Polar research: Reports and findings

Ice-trapped pollutants poison polar bears' diets

(Deutsche Welle, 20 August 2010) -- The iconic symbol of the Arctic — the polar bear — is under threat from the twin challenges of climate change and lingering chemical pollutants, such as PCBs (polychlorinated biphenyls), which are not breaking down in the region's cold waters. A comprehensive review of research on polar wildlife published recently in the journal Science of The Total Environment has concluded that the retreat of sea ice cover in the Arctic as a result of climate change could increase the exposure of species such as polar bears to a range of man-made chemical compounds, including flame retardants and substances used to harden plastics.

Scientists believe that lingering pollutants, locked up in the polar ice for decades, could be released into the ocean as the ice cover retreats. According to estimates, annual sea-ice cover in the Arctic in the northern summer is now between a quarter and a third less than it was 30 years ago. The world's polar bear population is currently estimated to total between 20,000 and 25,000 specimens, despite the Arctic region's vast size. Polar bears are particularly at risk, according to Bjorn Munro Jenssen, a Norwegian eco-toxicologist and polar bear expert who contributed to the review, because they are at the very top of the Arctic food chain.

"These contaminants are bio-accumulated and bio-magnified up the food chain," said Jenssen. "So the higher you are in the food chain, the higher are the contaminants."The fact that a polar bear's favorite meal is seal does not help matters in any way.

"These contaminants accumulate in fat, and the polar bear only eats the fat of the seals," explained Jenssen. "So they are exposed to huge amounts of fat when they eat one seal — and they eat maybe a few hundred or a thousand seals per year — and then it accumulates." Jenssen emphasizes that the contaminants involved are toxic, even in low concentrations. They can affect a polar bear's hormone system and immune system, which is likely to have an influence on the animals' overall reproduction and survival rates.


Posted by Amanda Graham – 22 August 2010; 12:56:17 PM – Permalink  

Borehole network confirms, permafrost is thawing worldwide

(Victoria Barber/Arctic Sounder, 13 August 2010) -- An expanded network of boreholes across the northern hemisphere has confirmed that permafrost throughout polar and sub-polar regions is thawing, say scientists who studied the topic during International Polar Year. "You look at a whole hemisphere and see the patterns everywhere," said Vladimir Romanovsky, a professor with the snow, ice and permafrost group at the University of Alaska Fairbanks Geophysical Institute, and lead author of a paper documenting the research.

Romanovsky and his colleagues launched a campaign to improve the global network of boreholes for International Polar Year, a science program focused on the Arctic and Antarctic that ran from 2007 to 2009. Boreholes are holes drilled anywhere from 6 feet to over 200 feet into the ground and equipped with sensors to allow scientists to measure soil conditions. The researchers established nearly 300 boreholes, nearly doubling the existing network. "The heart of monitoring is the measuring of the temperatures in boreholes," Romanovsky said.

Using information collected from 575 boreholes located throughout North America, Russia and the Nordic region, researchers found that permafrost temperatures during the International Polar Year were as much as 2 degrees Celsius (35.6 degrees Fahrenheit) warmer than they were 20 or 30 years ago. Also, they found that the rate permafrost changes decreases the closer it gets to 0 degrees Celsius - basically, cold permafrost thaws more quickly than warmer permafrost. Romanovsky, Sharon L. Smith and Hanne H. Christianson published their findings in the April/June 2010 edition of the science publication Permafrost and Periglacial Processes.


Posted by Amanda Graham – 21 August 2010; 8:20:19 PM – Permalink  

Exclusive: Historic Northwest Passage wreckage discovered beneath Beaufort Sea

(Don Martin/Calgary Herald, 28 July 2010) -- MERCY BAY, N.W.T. - The historic ship whose crew discovered Canada’s Northwest Passage has been found 155 years after it was abandoned and sank in this oft-frozen Arctic bay atop isolated Banks Island. The wreck of HMS Investigator was detected in shallow water within days of Parks Canada archeologists launching their ambitious search for the 422-tonne ship from this chilly tent encampment on the Beaufort Sea shoreline.

“It’s sitting upright in silt; the three masts have been removed, probably by ice,” said Ifan Thomas, Parks Canada’s superintendent of the western Arctic Field Unit. “It’s a largely intact ship in very cold water, so deterioration didn’t happen very quickly.” The clear Arctic water makes it possible to glimpse the outline of the ship’s outer deck, which is only eight metres below the surface. Three graves were also found Tuesday. They are undoubtedly the remains of British sailors who succumbed to disease in the final months of the ship’s three-year Arctic ordeal.

 “In anthropological terms, this is the most important shipwreck in history,” said senior marine archeologist Ryan Harris. “It’s a bit like finding a Columbus ship in the Arctic.”


Posted by Amanda Graham – 28 July 2010; 6:11:18 PM – Permalink  

Mitochondrial genome analysis revises view of the initial peopling of North America

(Cold Spring Harbor Laboratory press release, 28 June 2010) -- 29 June 2010 - The initial peopling of North America from Asia occurred approximately 15,000-18,000 years ago, however estimations of the genetic diversity of the first settlers have remained inaccurate. In a report published online today in Genome Research (www.genome.org), researchers have found that the diversity of the first Americans has been significantly underestimated, underscoring the importance of comprehensive sampling for accurate analysis of human migrations. Substantial evidence suggests that humans first crossed into North America from Asia over a land bridge called Beringia, connecting eastern Siberia and Alaska. Genetic studies have shed light on the initial lineages that entered North America, distinguishing the earliest Native American groups from those that arrived later. However, a clear picture of the number of initial migratory events and routes has been elusive due to incomplete analysis.

In this work, an international group of researchers coordinated by Antonio Torroni of the University of Pavia in Italy performed a detailed mitochondrial genome analysis of a poorly characterized lineage known as C1d. Mitochondrial DNA (mtDNA) is passed down through the maternal lineage, and mtDNA sequence markers are extremely useful tools for mapping ancestry. Similar to other haplogroups that were among the first to arrive in North America, C1d is distributed throughout the continent, suggesting that it may have been also present in the initial founding populations. However, C1d has not been well represented in previous genetic analyses, and the estimated age of approximately 7,000 years, much younger than the other founding haplogroups, was likely inaccurate.

To resolve these inconsistent lines of evidence, the group sequenced and analyzed 63 C1d mtDNA genomes from throughout the Americas. This high-resolution study not only confirmed that C1d was one of the founding lineages in North America 15,000 to 18,000 years ago, but revealed another critical insight. "These first female American founders carried not one but two different C1d genomes," said Ugo Perego of the Sorenson Molecular Genealogy Foundation and primary author of the study, "thus further increasing the number of recognized maternal lineages from Beringia."

These findings raise the number of founding maternal lineages in North America to fifteen. Furthermore, this work emphasizes the critical need for comprehensive analysis of relevant populations to gather a complete picture of migratory events. Alessandro Achilli of the University of Perugia, a coauthor of the report, suggests that the number of distinct mitochondrial genomes that passed from Asian into North America is probably much higher. "These yet undiscovered maternal lineages will be identified within the next three to four years," Achilli noted, "when the methodological approach that we used in our study will be systematically applied."

[Note: The article is open source and may be found here.]


Posted by Amanda Graham – 10 July 2010; 10:39:48 PM – Permalink  

New language research supports land bridge evidence

(Mary Beth Smetzer/Fairbanks Daily News-Miner via The Associated Press and via Anchorage Daily News, 6 July 2010) -- FAIRBANKS -- Research on a language connection between Asia and North America supports archaeological and genetic evidence for a Bering Strait land bridge, and the discovery is being endorsed by a growing list of scholars in linguistics and other sciences.  Western Washington University linguistics professor Edward Vajda has been studying the isolated Ket people of Central Siberia. His work is revealing more and more examples of an ancient language connection with the language family of Na-Dene, which includes Tlingit, Gwich'in, Dena'ina, Koyukon, Navajo, Carrier, Hupa, Apache and about 45 other languages.

In 2008, Vajda aired his hypothesis at a symposium in Alaska organized by James Kari of the University of Alaska Native Language Center. Vajda was trained in Slavic languages but became interested in Ket in the late 1980s, when he came across a book in Russian about the near extinct language in Siberia. His interest grew, and over the years he has engaged in extensive research, meeting Ket speakers twice in Germany, in southern Siberia and in Ket villages along the Yenisei River in central Siberia. To reach the remote Ket area, Vajda traveled via six airplanes, three trains and a 4 1/2-hour helicopter ride that sometimes barely cleared the tops of the Siberian spruce forests. Of the 1,200 Ket people, only about 100, all older than 55, still speak the language. ...  

The importance of studying a disappearing language goes far beyond a personal linguistic interest, Vajda explained. "It's a new way to understand human prehistory before there were historians to write it down. Isolated languages like Ket have developed features that are very unusual and interesting, and they help us to understand the human mind and human language ability."

"We linguists should not be the focus of attention here," Vajda added. "What is important are the languages and especially the Native communities themselves." Vajda takes no credit for coming up with the Asian language connection. "People developed the beginnings of these ideas even 300 years ago, and in 1923 someone made the specific claim I am arguing for. My work builds on vocabulary comparisons made by other linguists in the late 1990s as well."


Posted by Amanda Graham – 6 July 2010; 5:54:23 PM – Permalink  

Arctic Biodiversity Trends 2010: Selected indicators of change report

Unique Arctic habitats for flora and fauna, including sea ice, tundra, lakes, and peatlands have been disappearing over recent decades, and some characteristic Arctic species have shown a decline. The changes in Arctic Biodiversity have global repercussions and are further creating challenges for people living in the Arctic.

The above statements are examples on the key findings describing changes in Arctic biodiversity that is presented in ‘The Arctic Biodiversity Trends – 2010: Selected Indicators of Change’, a new report recently launched synthesizing scientific findings on the status and trends for selected biodiversity in the Arctic issued by the Conservation of Arctic Flora and Fauna (CAFF) Working Group under the Arctic Council.

This report was recently launched at the Arctic Council Deputy Ministers’ meeting in Copenhagen on May 27. UNEP/GRID-Arendal contributed to the report through editing, graphic design and the production of all cartographics.

Download the full report. (23 mb)

Maps and Graphics from the report are available in:
GRID-Arendal Maps & Graphics Library


Posted by Amanda Graham – 13 June 2010; 1:02:48 PM – Permalink  

Shift in Gulf stream could be deadly

(Lillian Rizzo/The Ticker, 10 May 2010) -- An asteroid might not have been the reason for the dinosaurs’ extinction. New research by Dr. Gregory Price of Plymouth University, who has been studying fossils and minerals from Arctic Svalbard, shows that a change in the Atlantic Gulf Stream may have led to the wipe out of dinosaurs.

“World’s seas plummeted 9 degrees Celsius from 13 degrees Celsius to just 4 degrees Celsius around 137 million years ago,” according to the dailymail.co.uk. The findings were published in the newspaper on April 23 when Price spoke to the publication. Price and Dr. Elizabeth Nunn of Johannes Gutenburg Universitat in Mainz, Germany, have been studying in the Arctic Svalbard since 2005.  ... During the Cretaceous period, the area was filled with dinosaurs and had warm, shallow seas and swamps. While scientists have long attributed the extinction of the dinosaurs to an asteroid or comet impact, this new research reveals that it was a series of environmental changes beginning with a drop in sea temperature in the Cretaceous period that led to extinction. The plunge in temperature is attributed to high carbon dioxide levels in the atmosphere that caused global warming, similar to the earth’s current situation now.

“The drop in temperatures may well have been caused by a change in ocean circulation, much like what is being predicted for the Gulf Stream,” said Price in The Daily Mail. “We believe dinosaurs were most likely to be cold-blooded creatures and would have needed the warmth to keep them alive. If they were unable to migrate south, they could have been wiped out.” Price and his staff brought the evidence back to Plymouth to be analyzed. There is evidence to suggest that this change in climate can occur again, except less abruptly. According to the Wood Hole Oceanographic Institution, “Abrupt regional cooling and gradual global warming can unfold simultaneously ... greenhouse warming is a destabilizing factor that makes abrupt climate change more probable.”


Posted by Amanda Graham – 13 May 2010; 10:22:49 AM – Permalink  

Asthma rates in Inuit below national average

(Arctic Institute of North America press release via EurekAlert, 3 May 2010) -- OTTAWA, ON - New research shows Inuit populations in the Canadian Arctic have asthma rates far below Aboriginal people in other parts of Canada, especially those in urban centres. The study, published recently in the International Journal of Circumpolar Health, says reported cases of asthma in Inuit children was 5%, compared to 12% for all other Aboriginal groups. In Inuit adults, 5.4% of respondents had been diagnosed with asthma, compared to the national average of 11%.

Eric Crighton, lead author of the paper and geography professor at the University of Ottawa, says while it's not unusual to see lower rates of asthma in rural areas, that doesn't always mean rural residents are healthier than their urban cousins. While there is less air pollution in rural regions than in cities, in most other determinants of health – such as income, education, housing and the availability of health care - the North scores extremely low.

"It's my personal opinion ... that it's the limited access to health care that explains this finding. Aboriginal populations are heavily underserved (by health care) all across Canada, but in the North it's a bit more extreme," says Crighton, adding "The biggest determinant of doctor reported asthma is whether you've been to the doctor." The study is based on an analysis of data in Statistics Canada's 2001 Aboriginal People's Survey. A total of 60,500 adults in northern and southern Canada were surveyed. A child and youth questionnaire was administered to 34,495 respondents (parent, grandparents, etc.).


Posted by Amanda Graham – 4 May 2010; 1:43:44 AM – Permalink  

Inuit preschoolers show changing patterns of growth

(Ruth Klinkhammer/AINA via Medical News Today, 20 April 2010) -- Inuit preschoolers in Nunavut are as tall as their U.S. counterparts but they're also heavier, according to a new study published in the online edition of the International Journal of Circumpolar Health. This represents a remarkable change from previous work showing Inuit infants began life with equivalent birth lengths, but were falling behind by the time they were six months old.

"This is in many ways a good news story," says Dr. Tracey Galloway, lead author and a Post-doctoral Fellow at the University of Toronto's Dalla Lana School of Public Health. "Height reflects overall health status over a lifetime and over generations."

Unlike weight, which can fluctuate quickly, it takes decades for changes in health to be reflected in the height of a population. Factors influencing height include nutrition of the child, maternal health and diet, and infectious disease rates. However, says Galloway, it's impossible to know whether this trend will continue because school-aged children and youth have not been recently surveyed. The study of 26% of three- to five-year-olds in 16 Nunavut communities marks the first time data on the height and weight of preschoolers has been collected for Inuit populations living in the North.

The data are from the International Polar Year Nunavut Inuit Child Health Survey led by McGill University, the University of Toronto and territorial and community partners.


Posted by Amanda Graham – 29 April 2010; 1:45:30 AM – Permalink  

Research shows part of Alaska inundated by ancient megafloods

(University of Washington press release via EurekAlert, 28 April 2010) -- New research indicates that one of the largest fresh-water floods in Earth's history happened about 17,000 years ago and inundated a large area of Alaska that is now occupied in part by the city of Wasilla, widely known because of the 2008 presidential campaign. The event was one of at least four "megafloods" as Glacial Lake Atna breached ice dams and discharged water. The lake covered more than 3,500 square miles in the Copper River Basin northeast of Anchorage and Wasilla.

The megaflood that covered the Wasilla region released as much as 1,400 cubic kilometers, or 336 cubic miles, of water, enough to cover an area the size of Washington, D.C., to a depth of nearly 5 miles. That water volume drained from the lake in about a week and, at such great velocity, formed dunes higher than 110 feet, with at least a half-mile between crests. The dunes appear on topographical maps but today are covered by roads, buildings and other development.

"Your mind doesn't get around dunes of that size. Obviously the water had to be very deep to form them," said Michael Wiedmer, an Anchorage native who is pursuing graduate studies in forest resources at the University of Washington.

Wiedmer is the lead author of a paper describing the Wasilla-area megaflood, published in the May edition of the journal Quaternary Research. Co-authors are David R. Montgomery and Alan Gillespie, UW professors of Earth and space sciences, and Harvey Greenberg, a computer specialist in that department.

By definition, a megaflood has a flow of at least 1 million cubic meters of water per second (a cubic meter is about 264 gallons). The largest known fresh-water flood, at about 17 million cubic meters per second, originated in Glacial Lake Missoula in Montana and was one of a series of cataclysmic floods that formed the Channeled Scablands of eastern Washington. The megaflood from Glacial Lake Atna down what is now the Matanuska River to the Wasilla region might have had a flow of about 3 million cubic meters per second. Another suspected Atna megaflood along a different course to the Wasilla region, down the Susitna River, might have had a flow of about 11 million cubic meters per second. The researchers also found evidence for two smaller Atna megafloods, down the Tok and Copper rivers.


Posted by Amanda Graham – 29 April 2010; 1:41:58 AM – Permalink  

Warming soil releases more greenhouse gas

(Randy Shore/Vancouver Sun, 19 April 2010) -- Warming soils in Canada's North are releasing a vast store of carbon that has been inert for millennia, which could further accelerate the rate of climate change, according to the author of a new study published in the journal Nature. Field work conducted in Canada by the study's co-author Ben Bond-Lamberty suggests that the release of carbon in the soils of the world's tundra and northern boreal forests — about one third of all terrestrial carbon — is already underway, and he says soils all over the world are releasing more carbon dioxide as temperatures rise.

Bond-Lamberty and co-author Allison Thomson at Maryland's Joint Global Change Research Institute analysed data from 439 studies on soil respiration conducted in 1,434 locations in every corner of the world and found that plant growth, decomposition and microbial activity in the soil release about 98 billion tonnes of CO2 into the atmosphere every year, about 10 times the amount that humans release by burning fossil fuels, he said. That phenomenon by itself is not worrisome because soil has always released CO2 as part of a complex carbon cycle in which released carbon is absorbed by the world's oceans and growing plants in equilibrium.

"It's not surprising that higher temperatures have given rise to greater soil respiration," said Bond-Lamberty. "That's just basic science." But the amount of carbon being released by soils has increased by .01 per cent a year over the past 20 years as the world's temperature has increased and may be liberating carbon that has been stored in peat bogs, boreal forests and frozen soils for thousands of years. The danger is that the release of so-called "old carbon" could create a loop in which rising temperatures lead to the release of more carbon, which in turn raises the world's temperature, leading to accelerated carbon release, Thomson told The Sun. Canada's Arctic is one of the world's largest deposits of old carbon.


Posted by Amanda Graham – 22 April 2010; 2:13:19 PM – Permalink  

Report: March was Earth’s warmest on record

(USAToday, 16 April 2010) -- Although a large chunk of the USA didn't get in on the warmth in March, the rest of the world sure did. March was the warmest March ever recorded worldwide, the National Climatic Data Center (NCDC) reported Thursday. NCDC records go back to 1880. Another source, the University of Alabama-Huntsville, also reported that March 2010 was the warmest March since their climate records began in 1979.

According to the climate center, the combined global land and ocean average surface temperature in March was 56.3 degrees, which is 1.39 degrees above the 20th-century average of 54.9 degrees. Additionally, the worldwide ocean surface temperature was the highest for any March on record -- 1.01 degree above the 20th century average of 60.7 degrees. This was the 34th consecutive March with global land and ocean temperatures above the 20th century average.

The warmth in northern Canada and the Arctic was also noteworthy. Temperatures there soared to as much as 15 degrees above average for the month, the University of Alabama-Huntsville noted. The UAH dataset uses satellite measurements of temperatures from the surface up to about five miles in altitude.

"We have seen similar large anomalies on a month-to-month basis in the Arctic during the cold months (Dec. - March) in the past," noted climatologist John Christy of the University of Alabama-Huntsville. "This particular case is interesting because it persisted somewhere in the Arctic for four months."


Posted by Amanda Graham – 18 April 2010; 11:26:08 AM – Permalink  

Hudson Bay belugas focus of 2 studies

(CBC News, 12 April 2010) -- Federal fisheries scientists have been studying beluga whales in Hudson Bay, where changes to sea ice may have led to dropping mercury levels in some female whales but an emerging threat from another whale species. Although killer whales have been spotted in Hudson Bay since the 1950s, people in area communities have reported seeing more of them in recent years, said Steve Ferguson, a research scientist with the federal Department of Fisheries and Oceans. Ferguson, who works in the department's Arctic aquatic research division in Winnipeg, said he is analyzing hormone levels from beluga whale samples to determine how the belugas are reacting to the rising killer-whale threat.

"The indication is that the killer whales are there a little longer, now there's less sea ice, and maybe they're doing a little more attacking on the beluga," Ferguson told CBC News. "We're taking samples from them [belugas] to see if they're finding it more stressful recently, trying to live with killer whales around that are trying to kill them and eat them." Ferguson's research complements work being done by fellow DFO research scientist Gary Stern, who has found mercury contaminant levels have gone down in female beluga whales in Hudson Bay.

Stern found that methyl mercury levels in the muscle tissue of female beluga whales harvested in Arviat, Nunavut, have dropped by 32 per cent between 1984 and 2008. Longer ice-free periods on Hudson Bay could be affecting what and where the whales are eating, as the female belugas may be eating less contaminated prey that are found in offshore areas, Stern said.


Posted by Amanda Graham – 15 April 2010; 8:24:44 AM – Permalink  

Scientists turn to Inuit traditions to collect data on Arctic weather

(Thandi Fletcher/Canwest News Service via The Gazette, 11 April 2010) -- OTTAWA - Using traditional Inuit weather knowledge passed down through generations, environmental scientists have uncovered new data on Arctic climate change. In a study appearing this month in the journal Global Environmental Change, researchers working closely with Inuit elders were able to "zero in on what we'd been hearing from the Inuit people for a number of years," said Elizabeth Weatherhead, chief author of the study and environmental scientist at the University of Colorado at Boulder.

Since the early 1990s, Inuit hunters and elders have been noticing increasingly unpredictable weather patterns in their Arctic communities. But their observations didn't match up with scientific weather data. Scientific measurements suggested "weather persistence" around the world was actually becoming "more firm" with less variation, said Weatherhead. "When we have warm spells or cold spells, they last a few days, not three weeks non-stop," she explained. That time cycle is shifting on a global scale, she said, with spells now lasting longer than before. But Inuit people said the opposite was happening in their part of the world — that Arctic weather was behaving unpredictably. "[Inuit people] were identifying these changes in the weather and identifying how important it was, long before scientists realized, 'Hey, this is happening,'" said Weatherhead. Until now, scientific studies of climate change focused mainly on mean temperatures, according to the study's researchers. ...

The researchers are still unsure as to what is causing Arctic weather unpredictability, but a few theories have been put forward. One of those is climate change, Weatherhead said, "but it's not clear yet if this is (climate change) driven by greenhouse gases." Mead Treadwell, chair of the U.S. Arctic Research Commission, said he believes a few factors, including wind patterns and more extreme temperatures, are playing a part in the thinning sea ice. "The biggest change I've seen is the withdrawal of sea ice," he said. ... Weatherhead said her team's work with Inuit elders demonstrates how important it can be for scientists to combine their methods with traditional, indigenous knowledge.


Posted by Amanda Graham – 12 April 2010; 12:00:08 PM – Permalink  

New narwhal survey boosts population estimate

(CBC News, 9 April 2010) -- The number of narwhal in Baffin Bay is estimated at more than twice the previous figure after a recent survey using new techniques, say scientists with the Department of Fisheries and Oceans. Previously estimated at between 20,000 and 30,000, the Baffin Bay population is now said to be more than 60,000. One of the new surveying techniques involves a formula to estimate the number of narwhal below the surface at any given time, says Pierre Richard, a research scientist with the Department of Fisheries and Ocean. Past surveys counted only whales on the ocean surface, not those beneath it, he said. For the most recent count, researchers attached trackers to more than a dozen whales. "We found that narwhal on average spent one-third of their time at the surface. So for every animal that you would see at the surface, there are another two below the surface," said Richard. ... The chair of the Hunters and Trappers Organization in Pond Inlet, Jayko Alooloo, says the new numbers are not a surprise. Still, he says there are fewer whales in certain places, such as Eclipse Sound. Alooloo says hunters worry that increased marine traffic, snowmobiles, and the placing of trackers on whales is causing narwhal to bypass former hunting zones.


Posted by Amanda Graham – 11 April 2010; 11:08:25 PM – Permalink  

Deep freeze caused by melting of ice sheet

(CBC News, 1 April 2010) -- The melting of a giant North American ice sheet 13,000 years ago caused the Gulf Stream to shut down and triggered rapid cooling on a global scale, suggests new research. The Big Freeze or Younger Dryas occurred suddenly when the world was just coming out of a glacial period. Temperatures were rising between 15,000 years ago and 13,000 years ago, when suddenly the trend reversed and glacial conditions returned for another 1,400 years. The cause, say scientists at the University of Sheffield, was a flood triggered by the melting of the Laurentide ice sheet, which covered much of North America. The flood caused fresh water to mix with salt water in the Arctic Ocean, causing more sea-ice to form and move into the North Atlantic, shutting down the Gulf Stream. With the Gulf Stream halted, warm water failed to circulate across the Atlantic, causing temperatures in Europe to plunge.

The Sheffield scientists are basing their findings on signs of erosion in sediments contained in cliff sections within the Mackenzie Delta. The delta lies at the end of the Mackenzie River where it enters the Beaufort Sea in Canada's Arctic. The researchers determined that this erosion could only have occurred if an enormous flood had occurred from the melting Laurentide ice sheet. "The combination of luminescence dating, landscape elevation models and sedimentary evidence allows an insight into what must have been one of the most catastrophic geological events in recent Earth's history," said Mark Bateman, one of the paper's authors, from the University of Sheffield's department of geography, in a release.

The research could shed light on what might happen if Arctic ice continues to melt, increasing the levels of fresh water in the North Atlantic. There is speculation the Gulf Stream could shut down once again, leading to massive cooling on a global scale. The paper is published in the April issue of Nature (doi:10.1038/464657a).


Posted by Amanda Graham – 7 April 2010; 11:52:21 AM – Permalink  

Stone Age Scandinavians unable to digest milk

(Uppsala University press release, 1 April 2010) -- The hunter-gatherers who inhabited the southern coast of Scandinavia 4,000 years ago were lactose intolerant. This has been shown by a new study carried out by researchers at Uppsala University and Stockholm University. The study, which has been published in the journal BMC Evolutionary Biology, supports the researchers' earlier conclusion that today's Scandinavians are not descended from the Stone Age people in question but from a group that arrived later.

"This group of hunter-gatherers differed significantly from modern Swedes in terms of the DNA sequence that we generally associate with a capacity to digest lactose into adulthood," says Anna Linderholm, formerly of the Archaeological Research Laboratory, Stockholm University, presently at University College Cork, Ireland. According to the researchers, two possible explanations exist for the DNA differences. "One possibility is that these differences are evidence of a powerful selection process, through which the Stone Age hunter-gatherers' genes were lost due to some significant advantage associated with the capacity to digest milk," says Anna Linderholm. "The other possibility is that we simply are not descended from this group of Stone Age people." The capacity to consume unprocessed milk into adulthood is regarded as having been of great significance for human prehistory.

"This capacity is closely associated with the transition from hunter-gatherer to agricultural societies," says Anders Götherström of the Department of Evolutionary Biology at Uppsala University. He serves as coordinator of LeCHE (Lactase persistence and the early Cultural History of Europe), an EU-funded research project focusing on the significance of milk for European prehistory." In the present case, we are inclined to believe that the findings are indicative of what we call "gene flow," in other words, migration to the region at some later time of some new group of people, with whom we are genetically similar," he says. "This accords with the results of previous studies." The researchers' current work involves investigating the genetic makeup of the earliest agriculturalists in Scandinavia, with an eye to potential answers to questions about our ancestors.


Posted by Amanda Graham – 5 April 2010; 12:49:05 PM – Permalink  

A river ran through it: Lake Agassiz drained northward

(University of Manitoba press release, 1 April 2010) -- A team of researchers have found evidence that climate change on a global scale took place about 13,000 years ago, caused by a flood of biblical proportions. Previous research had suggested that a massive outpouring of water from glacial Lake Agassiz in Canada may have travelled down the St. Lawrence eastward and out into the Atlantic Ocean, causing significant global climate change. But, writing in the journal Nature this week, geologists from England and Canada have discovered that the outflow likely went north into the Arctic Ocean instead. Lake Agassiz was a large body of water that covered much of what is now the Canadian prairies, created by the damming of northward drainage by the huge ice sheet that covered much of Canada at this time.

The team of geologists examined boulder gravel in the Athabasca River Valley just north of Fort McMurray, Alberta. This material was deposited when thousands of cubic kilometres of water from glacial Lake Agassiz rushed through the area many millennia ago. Most importantly, the dating of deposits related to this flood far downstream, near the mouth of the Mackenzie River, has established that this catastrophic flood occurred 13,000 years ago. This coincides with the start of a well-documented cooling period around the globe known as the Younger Dryas, which began a thousand-year-long cold spell. ...

“This new evidence adds to our view that the outburst flood from Lake Agassiz did lead to a change in ocean circulation and climate cooling,” explains research team member James Teller, geological sciences, University of Manitoba. “This may mean that the ice in the Arctic Ocean was forced out into the North Atlantic and helped change ocean circulation.”


Posted by Amanda Graham – 4 April 2010; 7:15:15 PM – Permalink  

Greenland ice sheet losing mass on northwest coast

(University of Colorado at Boulder press release via EurekAlert! 23 March 2010) -- Ice loss from the Greenland ice sheet, which has been increasing during the past decade over its southern region, is now moving up its northwest coast, according to a new international study. Led by the Denmark Technical Institute's National Space Institute in Copenhagen and involving the University of Colorado at Boulder, the study indicated the ice-loss acceleration began moving up the northwest coast of Greenland starting in late 2005.

The team drew their conclusions by comparing data from NASA's Gravity and Recovery Climate Experiment satellite system, or GRACE, with continuous GPS measurements made from long-term sites on bedrock on the edges of the ice sheet. The data from the GPS and GRACE provided the researchers with monthly averages of crustal uplift caused by ice-mass loss.

The team combined the uplift measured by GRACE over United Kingdom-sized chunks of Greenland while the GPS receivers monitor crustal uplift on scales of just tens of miles. "Our results show that the ice loss, which has been well documented over southern portions of Greenland, is now spreading up along the northwest coast," said Shfaqat Abbas Khan, lead author on a paper that will appear in Geophysical Research Letters. The team found that uplift rates near the Thule Air Base on Greenland's northwest coast rose by roughly 1.5 inches, or about 4 centimeters, from October 2005 to August 2009.

Although the low resolution of GRACE -- a swath of about 155 miles, or 250 kilometers across -- is not precise enough to pinpoint the source of the ice loss, the fact that the ice sheet is losing mass nearer to the ice sheet margins suggests the flows of Greenland outlet glaciers there are increasing in velocity, said the study authors.


Posted by Amanda Graham – 28 March 2010; 2:08:32 PM – Permalink  

Number of High Arctic animals declining

(CBC News, 18 March 2010) -- Animals in the Arctic have increased in number over the last 40 years, but populations closest to the North Pole are shrinking, a new international study says. The report, commissioned by the Circumpolar Biodiversity Monitoring Program (CBMP) and funded by the government of Canada, found that overall, the number of mammals, birds and fish in the Arctic has increased by 16 per cent since 1970. The Arctic Species Trend Index, released Wednesday at a conference in Miami, credited hunting restrictions in place for decades with the animals' recovery. The number of geese, for example, has doubled, and certain species of whale are also recovering. The biggest recovery was in the southernmost parts of the Arctic, where the number of animals was up 46 per cent from 1970 to 2004. In sharp contrast, though, is the High Arctic, the area closest to the North Pole. The number of animals dropped by 25 per cent in the same time period, while the number of caribou was down by about one-third."What we're seeing is that there's winners and losers with rapid changes in the Arctic," said Mike Gill, a Canadian government researcher and study co-author. Gill is also chair of the CBMP. Louise McRad of the Zoological Society of London said the decrease near the North Pole is most worrisome because the effects of climate change are most dramatic in that area and are expected to worsen. The pressure brought by the loss of sea ice will only increase, she said. Gill said there isn't enough evidence to blame climate change directly for the loss of animals, but it is "largely in line with what would be predicted with climate change."

Posted by Amanda Graham – 20 March 2010; 2:14:50 PM – Permalink  

High Arctic species on thin ice

(RedOrbit, 17 March 2010) -- A new assessment of the Arctic's biodiversity reports a 26 percent decline in species populations in the high Arctic. Populations of lemmings, caribou and red knot are some of the species that have experienced declines over the past 34 years, according to the first report from The Arctic Species Trend Index (ASTI), which provides crucial information on how the Arctic's ecosystems and wildlife are responding to environmental change. While some of these declines may be part of a natural cycle, there is concern that pressures such as climate change may be exacerbating natural cyclic declines.

In contrast, population levels of species living in the sub-Arctic and low Arctic are relatively stable and in some cases, increasing. Populations of marine mammals, including bowhead whales found in the low Arctic, may have benefited from the recent tightening of hunting laws. Some fish species have also experienced population increases in response to rising sea temperatures.

"Rapid changes to the Arctic's ecosystems will have consequences for the Arctic that will be felt globally. The Arctic is host to abundant and diverse wildlife populations, many of which migrate annually from all regions of the globe.

This region acts as a critical component in the Earth's physical, chemical, and biological regulatory system," says lead-author Louise McRae from the Zoological Society of London (ZSL). Data collected on migratory Arctic shorebirds show that their numbers have also decreased. Further research is now needed to determine whether this is the result of changes in the Arctic or at other stopover sites on their migration. ...

The findings of the first ASTI report will be presented at the 'State of the Arctic' Conference in Miami, USA. The full report will be available to download from www.asti.is on Wednesday March 17th, 2010.


Posted by Amanda Graham – 17 March 2010; 6:07:58 PM – Permalink  

Humans off hook for muskox decline

(Randy Boswell/Canwest News Service via The Gazette, 10 March 2010) -- Scientists studying DNA from ancient muskox bones collected in Canada and elsewhere around the world have ruled out prehistoric human hunters as the cause of a steep decline 12,000 years ago in populations of the iconic northern species, now restricted largely to Greenland and the Canadian Arctic islands.

An international team of 20 researchers from eight countries — including paleontologists from the Yukon government and the Canadian Museum of Nature in Ottawa — found that a warmer, wetter climate at the end of the last ice age was chiefly to blame for the disappearance of the shaggy beast from most of its traditional range across the planet's northern frontier. And while hunting in recent centuries has wiped out pockets of muskox in more southerly locales — including areas in mainland Canada around Hudson Bay — the Canadian North has been a crucial refuge for the animal over the millennia as it survived climate swings that doomed such other species as the woolly mammoth.

Yukon paleontologist Grant Zazula, co-author of the landmark study published in the journal Proceedings of the National Academy of Sciences, said yesterday that a 50,000-year record of muskox remains found at Yukon's Herschel Island was key to unravelling the history of the species. He said recent melting of the island's permafrost means that "tons of bones get washed up on the beach" — a priceless resource for international scientists studying the evolution of the muskox, a grazing cousin of cows and bison that once occupied the entire circumpolar world.


Posted by Amanda Graham – 10 March 2010; 5:42:17 PM – Permalink  

Site yields clues to evolution

(Randy Boswell/Canwest News Service, 5 March 2010) -- Scientists studying an ancient meteorite crash site in the Canadian Arctic have detected traces of microbes that point to the key role played by impact craters in the evolution of life on Earth and could help determine whether life once existed on Mars. The discovery — hailed by an 11-member team of researchers from Canada, Britain, the U.S. and Sweden as a scientific "first" — was made at Devon Island's famous Haughton Crater, a uniquely dry and desolate geological gem probed frequently by experts from NASA because of its Mars-like features.

"Meteorite impact craters have been proposed as possible sites to find microbial life on Mars, as they are a focus for heat and water circulation," the research team, including University of Western Ontario geologist Gordon Osinski, state in a summary of their findings. The researchers examined meteorite-shocked rocks from numerous sites throughout the 24-kilometre-wide crater and found telltale traces of sulphur left behind by heat-loving, "thermophilic" bacteria that moved into the crash site following the impact.

"Evidence of widespread microbial activity" in the Canadian crater, the team says, has "shown for the first time that a crater was pervasively colonized by microbes, and that colonization of over 20 cubic kilometres of impact rock was rapid, within 10,000 years after impact, while the rock was still warm."


Posted by Amanda Graham – 7 March 2010; 11:24:38 AM – Permalink  

International team sequences ancient polar bear mitochondrial genome

(Andrea Anderson/GenomeWeb News, 1 March 2010) -- NEW YORK - An international research team led by investigators at the University of Oslo's Natural History Museum has sequenced the mitochondrial genome of an ancient polar bear, finding new clues about polar bears' evolutionary history and relationship to brown bears. In a paper scheduled to appear online this week in the Proceedings of the National Academy of Sciences, researchers from Norway, Iceland, and the US used Roche 454 sequencing to sequence the complete mitochondrial genome from 110,000- and 130,000-year old polar bear remains found in Norway several years ago.

The findings suggest the ancient polar bear lived right around the time that the lineage leading to modern polar bears' divergence from the lineage of a closely related group of brown bears — called the ABC brown bears — found on Alaska's Admiralty, Baranof and Chichagof Islands.

"It's basically a transitional link between brown bears and polar bears," co-lead author Charlotte Lindqvist, an evolutionary biology researcher at the University of Buffalo who performed some of the work as a post-doctoral researcher at the University of Oslo Natural History Museum, told GenomeWeb Daily News. "It truly is between at least brown bears from the ABC islands and polar bears." Lindqvist and her co-workers isolated DNA from ancient polar bear remains found at the Poolepynten site in western Norway's Svalbard Archipelago in 2004. The jawbone and canine tooth found at that site represent a rare find, partly because of polar bears' sea ice environment.

"Because polar bears live on the ice, their dead remains fall to the bottom of the ocean or get scavenged," senior author Øystein Wiig, a polar bear expert at the University of Oslo Natural History Museum, said in a statement. "They don't get deposited in the sediments like other mammals."


Posted by Amanda Graham – 3 March 2010; 6:59:44 PM – Permalink  

Permafrost line recedes 130 km in 50 years

(Université Laval press release, 17 February 2010) -- Quebec City - The southern limit of permanently frozen ground, or permafrost, is now 130 kilometers further north than it was 50 years ago in the James Bay region, according to two researchers from the Department of Biology at Université Laval. In a recent issue of the scientific journal Permafrost and Periglacial Processes, Serge Payette and Simon Thibault suggest that, if the trend continues, permafrost in the region will completely disappear in the near future.

The researchers measured the retreat of the permafrost border by observing hummocks known as "palsas," which form naturally over ice contained in the soil of northern peat bogs. Conditions in these mounds are conducive to the development of distinct vegetation—lichen, shrubs, and black spruce—that make them easy to spot in the field.

In an initial survey in 2004, the researchers examined seven bogs located between the 51st and 53rd parallels. They noted at that time that only two of the bogs contained palsas, whereas aerial photos taken in 1957 showed palsas present in all of the bogs. A second assessment in 2005 revealed that the number of palsas present in these two bogs had decreased over the course of one year by 86% and 90% respectively. Helicopter flyovers between the 51st and 55th parallels also revealed that the palsas are in an advanced state of deterioration over the entire James Bay area.

While climate change is the most probable explanation for this phenomenon, the lack of long-term climatic data for the area makes it impossible for the researchers to officially confirm this. Professor Payette notes, however, that the average annual temperature of the northern sites he has studied for over 20 years has increased by 2 degrees Celsius. "If this trend keeps up, what is left of the palsas in the James Bay bogs will disappear altogether in the near future, and it is likely that the permafrost will suffer the same fate," concludes the researcher affiliated to the Centre d'études nordiques.


Posted by Amanda Graham – 26 February 2010; 10:31:09 PM – Permalink  

New World's first humans may have come via Arctic

(Randy Boswell/Canwest News Service via Nunatsiaq News, 26 February 2010)** -- Two U.S. scientists have published a radical new theory about when, where and how humans migrated to the New World, arguing that the peopling of the Americas may have begun via Canada’s High Arctic islands and the Northwest Passage — much farther north and at least 10,000 years earlier than generally believed. The hypothesis — described as “speculative” but “plausible” by the researchers themselves — appears in the latest issue of the journal Current Biology [available free], which features a special series of new studies tracing humanity’s proliferation out of Africa and around the world beginning about 70,000 years ago.

The idea of an ancient Arctic migration as early as 25,000 years ago, proposed by University of Utah anthropologists Dennis O’Rourke and Jennifer Raff [get paper here], would address several major gaps in prevailing theories about how the distant ancestors of today’s aboriginal people in North and South America arrived in the Western Hemisphere. The most glaring of those gaps is the anomalous existence of a 14,500-year-old archeological site in Chile, near the southern extreme of the Americas, that clearly predates the time when East Asian hunters are thought to have first crossed from Siberia to Alaska via the Bering Land Bridge at the end of the last ice age some 13,000 years ago.

The new theory may also have implications for a lingering Canadian archeological mystery. For decades, the Canadian Museum of Civilization has stood largely alone in defending its view that the Yukon’s Bluefish Caves hold evidence of a human presence in the Americas — tool flakes and butchered mammoth bones — going back about 20,000 years. The Utah scientists, pointing to genetic affinities between certain central Asian populations and New World aboriginal groups, suggest an Arctic coastal migration may have begun from river outlets in present-day north-central Russia.


Posted by Amanda Graham – 26 February 2010; 5:54:51 PM – Permalink  

Grizzlies move in on polar bear habitat

(RedOrbit, 23 February 2010) -- Competition from other bears may threaten a polar bear population. Biologists affiliated with the American Museum of Natural History and City College of the City University of New York have found that grizzly bears are roaming into what was traditionally thought of as polar bear habitat—and into the Canadian province of Manitoba, where they are officially listed as extirpated. The preliminary data was recently published in Canadian Field Naturalist and shows that sightings of Ursus arctos horribilis in Canada's Wapusk National Park are recent and appear to be increasing in frequency.

"Grizzly bears are a new guy on the scene, competition and a potential predator for the polar bears that live in this area," says Robert F. Rockwell, a research associate at the Museum and a professor of Biology at CUNY. "The first time we saw a grizzly we were flying over the middle of Wapusk, counting fox dens, when all of the sudden Linda Gormezano, a graduate student working with Rockwell and a co-author of the paper, shouted 'Over there, over there—a grizzly bear.' And it wasn't a dirty polar bear or a moose—we saw the hump."

That sighting in August 2008 spurred Rockwell and Gormezano to look through records to get a better picture of the bear population in the park. There was no evidence of grizzly bears before 1996, not even in the trapping data from centuries of Hudson Bay Company operation. But between 1996 and 2008 the team found nine confirmed sightings of grizzly bears, and in the summer of 2009 there were three additional observations. "The opportunistic sightings seem to be increasing," says Gormezano. "This is worrying for the polar bears because grizzly bears would likely hibernate in polar bear maternity denning habitat. They would come out of hibernation at the same time and can kill polar cubs."

Before this study, researchers thought that the barren landscape north of the Hudson Bay was an impassable gap in resources for potentially migrating grizzly bears. But some U. arctos horribilis have managed to move from their historic ranges in the Rockies, the Yukon, and Nunavut, probably because of their flexible, mixed diet of berries and meat. The potential gap was navigable, and now some grizzly bears have reached the abundant caribou, moose, fish, and berries found to the south in Canada's Wapusk National Park.


Posted by Amanda Graham – 24 February 2010; 4:14:08 PM – Permalink  

Deep in sediments off Antarctica, Stanford scientists find insight into past -- and possible future -- climates

(PhysOrg.com, 18 February 2010) -- From the Antarctic Ocean, Earth scientist Rob Dunbar blogs about the challenges of drilling ancient deep-sea sediments -- and what he's found in them. If cabin fever is gnawing at you this winter, consider taking a vicarious voyage with Stanford Earth scientist Rob Dunbar, who is drilling in - and blogging from - the deep sea off the East Antarctic Ice Sheet. He's in search of clues to Earth's past climate, and his blog, full of video clips, photos and written entries, gives a lively account of an expedition to Wilkes Land, an area due south of Australia that has never been drilled before.

Dunbar and his fellow researchers are extracting cores of sediment from deposits under the ocean that were laid down over the last 50 million years or so, stretching back to a time when a balmier Antarctica was largely ice free and covered with forests. The team particularly wants to analyze sediments deposited about 34 million years ago, during the transition from that warm climate to a cooler one that produced the first growth of polar ice caps. Dunbar said the transition is thought to have been triggered by changes in the levels of carbon dioxide and other abrupt climate transitions in the past will help us better understand what lies ahead in our greenhouse future," he said.

Dunbar, a professor of environmental Earth system science, is on board the research vessel JOIDES Resolution, along with more than thirty other scientists including paleontologist Christina Riesselman, a graduate student in geological and environmental sciences. The ship set out from Wellington, New Zealand, in January and is scheduled to be out for a little over two months. Dunbar is blogging about the voyage for the Exploratorium as part of its Ice Stories project, which began covering Arctic and Antarctic scientific explorations during the International Polar Year (2007-2008).


Posted by Amanda Graham – 21 February 2010; 9:21:45 PM – Permalink  

Missing 'ice arches' contributed to 2007 Arctic ice loss

(NASA, 18 February 2010) -- PASADENA, Calif. - In 2007, the Arctic lost a massive amount of thick, multiyear sea ice, contributing to that year's record-low extent of Arctic sea ice. A new NASA-led study has found that the record loss that year was due in part to the absence of "ice arches," naturally-forming, curved ice structures that span the openings between two land points. These arches block sea ice from being pushed by winds or currents through narrow passages and out of the Arctic basin. Beginning each fall, sea ice spreads across the surface of the Arctic Ocean until it becomes confined by surrounding continents. Only a few passages — including the Fram Strait and Nares Strait — allow sea ice to escape.

"There are a couple of ways to lose Arctic ice: when it flows out and when it melts," said lead study researcher Ron Kwok of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We are trying to quantify how much we're losing by outflow versus melt."

Kwok and colleagues found that ice arches were missing in 2007 from the Nares Strait, a relatively narrow 30- to 40-kilometer-wide (19- to 25-mile-wide) passage west of Greenland. Without the arches, ice exited freely from the Arctic. The Fram Strait, east of Greenland, is about 400 kilometers (249 miles) wide and is the passage through which most sea ice usually exits the Arctic. Despite Nares' narrow width, the team reports that in 2007, ice loss through Nares equaled more than 10 percent of the amount emptied on average each year through the wider Fram Strait.

"Until recently, we didn't think the small straits were important for ice loss," Kwok said. The findings were published this month in Geophysical Research Letters.


Posted by Amanda Graham – 19 February 2010; 2:10:58 PM – Permalink  

Mackenzie River's fish contaminated with dangerous toxins: scientists

(Martin Mittelstaedt/Globe and Mail, 9 February 2010) -- Scientists studying burbot in the Mackenzie River, one of the country's most pristine rivers, have been surprised to discover that mercury, PCBs and DDT in the fish are rising rapidly, a finding they say is linked to climate change. The increase in the amount of harmful chemicals has been huge. In the period from the mid-1990s to 2008, PCBs have risen up to six times, DDT by three times, and mercury by 1.6 times in the burbot, a delicacy in the north described as tasting like a freshwater lobster.

Contaminant levels “going up so dramatically was quite surprising,” said Gary Stern, a senior scientist with the Department of Fisheries and Oceans and lead researcher on the study, which also involved scientists from the University of Manitoba and Geological Survey of Canada. Dr. Stern said the most plausible explanation for the trend is that as temperatures in the Arctic rise due to climate change, snow and ice cover are diminishing, leading to a profusion of algae, zooplankton and other aquatic microscopic life able to absorb pollutants from water. While this greening of the Arctic environment means there is more for wildlife to eat, it also allows harmful contaminants to enter the food chain in far greater amounts, he said.


Posted by Amanda Graham – 17 February 2010; 11:59:57 AM – Permalink  

Greenland ice loss driven by warming seas: study

(PhysOrg, 14 February 2010) -- Greenland's continent-sized icesheet is being significantly eroded by winds and currents that drive warmer water into fjords, where it carves out the base of coastal glaciers, according to studies released Sunday. The icy mass sitting atop Greenland holds enough water to boost global sea levels by seven metres (23 feet), potentially drowning low-lying coastal cities and deltas around the world.

At present, the ocean watermark is rising at around three millimetres (0.12 inches) per year, a figure that compares with 1.8mm (0.07 inches) annually in the early 1960s. But Greenland's contribution has more than doubled in the past decade, and scientists suspect climate change is largely to blame, although exactly how this is occurring is fiercely debated. Some theories point to air temperatures, which are rising faster in far northern latitudes than the global average. A rival idea is that shifting currents and subtropical ocean waters moving north are eroding the foundation of coastal glaciers, accelerating their slide into the sea, especially those inside Greenland's many fjords. Until now, however, these studies have been mainly based on mathematical models rather than observation.

A team of scientists led by Fiammetta Straneo of Woods Hole Oceanographic Institution in Massachusetts set out to help fill that data void. Working off of a ship in July and September 2008, the researchers took detailed measurements of the water properties in the Sermilik Fjord connecting Helheim Glacier in eastern Greenland with the ocean.

They found deep water streaming into the fjord was 3.0-4.0 degrees Celsius (37.4-39.2 degrees Fahrenheit), warm enough to cut into the base of the glaciers and hasten their plunge into the sea. Moored instruments left in the fjord for eight months showed that winds aligned with the coastline played a crucial role in the influx of these warmer waters.


Posted by Amanda Graham – 14 February 2010; 3:46:32 PM – Permalink  

New report: Traditional Aboriginal knowledge key to Boreal Forest conservation

(BorealCanada press release, 1 February 2010) -- OTTAWA - Traditional knowledge held by Canada’s Aboriginal people about the Boreal Forest offers western scientists a vitally important information source, according to a report published by the David Suzuki Foundation, the Canadian Boreal Initiative, and the Boreal Songbird Initiative. With the Boreal Forest facing increasing threats from climate change, habitat loss and fragmentation, and invasive species, this knowledge is more important than ever.

The report, Conservation Value of the North American Boreal Forest from an Ethnobotanical Perspective, describes the deep botanical and ecological knowledge that Canada’s Aboriginal peoples have gained over thousands of years of using the Boreal Forest as grocery, pharmacy, school, and spiritual centre. The report notes that the subsistence value of the Canada’s Boreal Forest to Aboriginal people in plant and animal foods alone could reach up to $575.1 million. Many other values have yet to be quantified.

“The deeply rooted knowledge of indigenous communities remains an essential but often overlooked element in conservation planning,” said Larry Innes, executive director of CBI. “This report contributes to building a better awareness among Canadians about the richness and diversity of plant use and knowledge among indigenous peoples.”

The report illustrates how scientists and policymakers often overlook ecological issues until a crisis arises. For example, although few plants species in the boreal region are classified as threatened or endangered under the federal Species at Risk Act or provincial and territorial species legislation, many face widespread human-induced pressures, including habitat loss and climate change.


Posted by Amanda Graham – 11 February 2010; 11:52:44 PM – Permalink  

Ancient man in Greenland has genome decoded

(Nicholas Wade/New York Times, 10 February 2010) -- The genome of a man who lived on the western coast of Greenland some 4,000 years ago has been decoded, thanks to the surprisingly good preservation of DNA in a swatch of his hair so thick it was originally thought to be from a bear. This is the first time the whole genome of an ancient human has been analyzed, and it joins the list of just eight whole genomes of living people that have been decoded so far. It also sheds new light on the settlement of North America by showing there was a hitherto unsuspected migration of people across the continent, from Siberia to Greenland, some 5,500 years ago. The Greenlander belonged to a Paleo-Eskimo culture called the Saqqaq by archaeologists. Using his genome as a basis, a team of researchers from the University of Copenhagen determined that the Saqqaq man’s closest living relatives were the Chukchis, people who live at the easternmost tip of Siberia. His ancestors split apart from Chukchis some 5,500 years ago, according to genetic calculations, implying that the Saqqaq people’s ancestors must have traveled across the northern edges of North America until they reached Greenland. ...

No traces of the Saqqaq people have been found in North America, said Michael H. Crawford, an expert on circumpolar populations at the University of Kansas and a co-author of the report. Because the land bridge that once connected Siberia and Alaska had long since foundered, the Saqqaq people might have crossed to Alaska on the winter ice or could have used the boats on which they hunted fish and seals. They evidently kept to Arctic latitudes, perhaps because more southerly regions were already occupied by the Inuit, or because they were better adapted to life in the Arctic, Dr. Rasmussen said. The Saqqaq man’s genome is so complete that the Danish researchers have been able to reconstruct his probable appearance and susceptibility to disease from the genetic information in his genome. They conclude that he would have had brown eyes because of variations, at four positions along his DNA, that are associated with brown eye color in East Asians. ...

Biologists used to think that DNA would be found only in the cells at the roots of the hair, not in the keratin of which the hair shaft is made. But it now seems that the cells become incorporated into the growing shaft and their DNA is sealed in by the keratin, protecting it from attack by bacteria and fungi. The Danish researchers, using an advanced DNA sequencing technology developed by Illumina of San Diego, reported that they were able to decode 80 percent of the ancient Greenlander’s genome to a high degree of accuracy. Their findings appear in the journal Nature.


Posted by Amanda Graham – 11 February 2010; 10:50:15 AM – Permalink  

Complex co-existence for indigenous peoples

(BarentsObserver, 3 February 2010) -- Tundra areas of the north may seem like endless wilderness with a huge potential for industrial activity. However, the activities of the industrial companies pose a challenge to the indigenous peoples' traditional use of the pasture lands and the reindeers migrating routes. In the Norwegian Barents Secretariat’s new report, Barents Review 2010, secretariat adviser Christina Henriksen writes about the complex challenges connected with co-existence of industry and indigenous peoples living in the Barents Region.

The natural resource potential of the north has contributed to an increased industrial focus on the region. North Russian and multinational companies have established activities in the region to exploit the rich deposits of oil, gas and minerals. In Nenets Autonomous Okrug as much as ninety percent of all the region's income is derived from the oil and gas industry. In recent years power has been continually transferred from local and regional authorities to the federal authorities, especially when it comes to management of natural resources.

"This has indirect impact on indigenous peoples, as discussions and negotiations regarding regional issues more often are carried out with representatives in Moscow, rather than in the respective regions," says Henriksen. Many times reindeer herders are not invited to give their view on new industrial projects in the area, since it is not mandatory to sign contracts with regional government bodies on production conditions for new industrial projects. ... Direct impact on indigenous peoples’ livelihood due to industrial expansion has required indigenous peoples in the Barents Region to join forces. Jointly, the different organizations and institutions work for the fulfillment of national and international obligations towards the indigenous peoples.


Posted by Amanda Graham – 6 February 2010; 11:52:14 PM – Permalink  

Report: Arctic warming could cost trillions of dollars

(Nunatsiaq News, 6 February 2010) -- Global warming in the Arctic will impose costs on the rest of the planet that could run into the trillions of dollars, a new economic report predicts. “The Arctic is the planet’s air-conditioning, and it’s starting to break down,” said Eban Goodstein, the economist who contributed a financial analysis of the report’s scientific findings. The report, by the Pew Environmental Group, attempts to calculate a dollar value for the effects of Arctic climate. The report found that if climate change continues at current rates, Arctic feedback loops will contribute the equivalent of 42 per cent of the current greenhouse gas emissions of the United States. That’s because changes in the Arctic environment also contribute to global warming. As the Arctic thaws it releases tonnes of methane, a greenhouse gas 25 times as potent as carbon dioxide when measured tonne per tonne. Also, white snow and ice reflect sunlight – and heat. Less snow and ice in the Arctic means less heat from the sun is reflected out into space and more is absorbed. “It’s becoming more and more dramatic as the climate is warmed,” said biologist Eugenie Euskirchen, the scientific contributor to the Pew report.


Posted by Amanda Graham – 6 February 2010; 11:02:38 PM – Permalink  

Arctic ice melting faster than feared: study

(CBC News, 5 February 2010) -- The head of the largest climate change study ever undertaken in Canada says the Arctic sea ice is thinning faster than expected. "It's happening much faster than our most pessimistic projections," said University of Manitoba Prof. David Barber, the lead investigator of the Circumpolar Flaw Lead study. A flaw lead is the term for open water between pack ice and coastal ice. The study aboard the Canadian Coast Guard research ship Amundsen began in July 2007 and involved 370 scientists from around the world. It was the first time a research vessel had ever remained mobile in open water in the Far North. Barber called the expedition climate scientists' "first opportunity to look at what the Arctic Ocean looks like in the middle of winter." They found that Arctic sea ice is disappearing faster than scientists expected.

"We're seeing it happen more quickly than our model thought [it] would happen," said Barber. "It's an early indicator of what we can expect to happen further south," Barber said at a news conference in Winnipeg. "We can expect things to happen faster here, too." Barber said the human impact on climate is being superimposed on the natural variation in climate and temperature. The result is more variability in the climate: warm spells are getting warmer and the cold spells are getting colder. The researchers also found that storms have become more frequent in the North as the sea ice thins.


Posted by Amanda Graham – 5 February 2010; 11:45:58 PM – Permalink  

Better food makes high-latitude animals bigger

(University of Chicago Press Journals press release via EurekaAlert via ScienceDaily, 28 January 2010) -- New research suggests that animals living at high latitudes grow better than their counterparts closer to the equator because higher-latitude vegetation is more nutritious. The study, published in the February issue of The American Naturalist, presents a novel explanation for Bergmann's Rule, the observation that animals tend to be bigger at higher latitudes.

Ever since Christian Bergmann made his observation about latitude and size in 1847, scientists have been trying to explain it. The traditional explanation is that body temperature is the driving force. Because larger animals have less surface area compared to overall body mass, they don't lose heat as readily as smaller animals. That would give big animals an advantage at high latitudes where temperatures are generally colder. But biologist Chuan-Kai Ho from Texas A&M University wondered if there might be another explanation. Might plants at higher latitudes be more nutritious, enabling the animals that eat those plants to grow bigger?

To answer that question, Ho along with colleagues Steven Pennings from the University of Houston and Thomas Carefoot from the University of British Columbia, devised a series of lab experiments. They raised several groups of juvenile planthoppers on a diet of cordgrass, which was collected from high to low latitudes. Ho and his team then measured the body sizes of the planthopppers when they reached maturity. They found that the planthoppers that fed the high-latitude grass grew larger than those fed low latitude grass. The researchers performed similar experiments using two other plant-eating species — grasshoppers and sea snails. "All three species grew better when fed plants from high versus low latitudes," Ho said. "These results showed part of the explanation for Bergmann's rule could be that plants from high latitudes are better food than plants from low latitudes." Although this explanation applies only to herbivores, Ho explained that predators might also grow larger as a consequence of eating larger herbivores.


Posted by Amanda Graham – 28 January 2010; 10:26:50 PM – Permalink  

Article: ‘Tropical’ diseases are common in Arctic dwellers, a survey finds

(Donald G. McNeil Jr./New York Times, 25 January 2010) -- The kind of worm and protozoan infections that are often called neglected “tropical” diseases are also common among aboriginal peoples living in the Arctic, according to a recent survey. Outbreaks of trichinosis, a larval-worm disease commonly associated with eating undercooked pork and carnivorous wild game, also occur among people who eat infected polar bear and walrus meat, and the Arctic harbors a unique species of the worm that can survive subzero temperatures. Mild infestations cause nausea and stomach pain; severe ones can kill.

In Alaska, there are sporadic human cases of a fish tapeworm known as diphyllobothriasis. Echinococcosis, a tapeworm disease that fills human lungs or livers with cysts that can crush blood vessels or kill if they rupture, needs both canines and hoofed animals in its life cycle. In New Zealand, it once thrived in sheep and working dogs; in the Arctic, it cycles between reindeer and elk and both wolves and domesticated dogs. It is declining in Alaska and Canada, where snowmobiles are replacing sled dogs, but is still common in Siberia and northern Russia.

Toxoplasmosis, a particular threat to pregnant women, also occurs in the Arctic, though its origins are mysterious. With domestic cats uncommon, it may be linked to wild lynx, but it seems to be picked up from eating caribou and seal.

The survey, "Neglected Infections of Poverty among the Indigenous Peoples of the Arctic" was published in PLoS Neglected Tropical Diseases by Dr. Peter J. Hotez, who edits the online journal. Cit: Hotez PJ (2010) Neglected Infections of Poverty among the Indigenous Peoples of the Arctic. PLoS Negl Trop Dis 4(1): e606. doi:10.1371/journal.pntd.0000606


Posted by Amanda Graham – 28 January 2010; 3:47:17 PM – Permalink  

Nature's Past: Episode 12 - Industrialization in Subarctic Environments [24:30]

(NiCHE, 19 January 2010) -- Between 1920 and 1960, Canada's northwest subarctic region experienced late-stage rapid industrialization along its large lakes. These included Lake Winnipeg, Lake Athabasca, Great Slave Lake, and Great Bear Lake. Powered by high-energy fossil fuels, the natural resources of the northwest were integrated into international commodity markets and distributed throughout the world. Whitefish from the large lakes found their way onto dinner plates in New York while uranium from Canada's northwest fueled the world's most destructive weapons, atomic bombs.

Professor Liza Piper joins us this month to discuss her new book The Industrial Transformation of Subarctic Canada from UBC Press. This book explores a region unfamiliar to most Canadians and how that space was transformed through industrial processes in the twentieth century. Rather than finding industrial technologies dominating the landscape of the northwest, Professor Piper found that humans used those technologies to assimilate nature. [See also other podcasts in History of the Environment at NICHE's iTunes page]


Posted by Amanda Graham – 24 January 2010; 9:41:36 PM – Permalink  

Scientists support Nunavut polar bear hunters

(Gabriel Zárate/Nunatsiaq News, 22 January 2010) -- Two of the most respected and influential wildlife conservation groups in the world have come out against calling polar bears an endangered species. TRAFFIC, the international non-governmental organization that monitors the trade of wild plants and animals and their products, has submitted documents opposing the reclassification of polar bears proposed by the U.S. government. TRAFFIC’s steering committee is composed of members of the World Wildlife Fund and the International Union for the Conservation of Nature.

“The threat to polar bears is not from trade. It is not really a concern at this time,” said Andrew Derocher, a member of the IUCN’s Polar Bear Specialist Group. “We are looking to the future, 40 years, for polar bears to be in trouble due to habitat loss and the effect of climate change.”


Posted by Amanda Graham – 23 January 2010; 1:15:22 PM – Permalink  

Ice is 'rotten' in the Beaufort Sea

(ScienceDaily, 23 January 2010) -- Recent observations show that Beaufort Sea ice was not as it appeared in the summer of 2009. Sea ice cover serves as an indication of climate and has implications for marine and terrestrial ecosystems. In early September 2009, satellite measurements implied that most of the ice in the Beaufort Sea either was thick ice that had been there for multiple years or was thick, first-year ice.

However, in situ observations made in September 2009 by Barber et al. show that much of the ice was in fact "rotten" ice — ice that is thinner, heavily decayed, and structurally weak due to a uniform temperature throughout. The authors suggest that satellite measurements were confused because both types of ice exhibit similar temperature and salinity profiles near their surfaces and a similar amount of open water between flows. The authors note that while an increase in summer minimum ice extent in the past 2 years could give the impression that Arctic ice is recovering, these new results show that multiyear ice in fact is still declining.

The results have implications for climate science and marine vessel transport in the Arctic. The research appears in the journal Geophysical Research Letters.


Posted by Amanda Graham – 22 January 2010; 11:57:19 PM – Permalink  

Oil from Exxon Valdez spill gets trapped in gravel beaches

(Roberta Kwok/Conservation Magazine, Journal Watch, 18 January 2010) -- Two decades after the Exxon Valdez released massive amounts of oil into Alaskan waters, remnants of the spill are still lingering on nearby beaches. Now, a study in Nature Geoscience has teased apart the reasons for the oil’s stubborn persistence.

Researchers studied a gravel beach in Alaska’s Prince William Sound and ran computer simulations of fluid movement. The beach had two layers: a highly permeable upper layer, which held the oil, and a less permeable lower layer. When the water table fell to a certain point, they found, the upper layer gradually released oil into the lower layer, where it got stuck.

The findings could apply to other gravel beaches, which are common in the mid- to high latitudes, the authors say. Such beaches can form two layers when waves and tides push small grains to the bottom. And the number of oil spills in the Arctic could soon go up as ice cover continues to melt, opening new passages to ships. DOI: 10.1038/NGEO749


Posted by Amanda Graham – 19 January 2010; 3:54:40 PM – Permalink  

Invading trees will cause warming over Arctic region

(Red Orbit, 14 January 2010) -- Contrary to scientists' predictions that, as the Earth warms, the movement of trees into the Arctic will have only a local warming effect, University of California, Berkeley, scientists modeling this scenario have found that replacing tundra with trees will melt sea ice and greatly enhance warming over the entire Arctic region.

Because trees are darker than the bare tundra, scientists previously have suggested that the northward expansion of trees might result in more absorption of sunlight and a consequent local warming. But UC Berkeley graduate student Abigail L. Swann, along with Inez Fung, professor of earth and planetary science and of environmental science, policy and management, doubted this local scenario because, while broad-leaved trees are dark, they also transpire a lot of water, and water vapor is a greenhouse gas that is well-mixed throughout the Arctic.

Taking account of this in a standard model of global warming, the researchers discovered that, while broad-leaved trees do absorb some additional sunlight, the water vapor they pump into the atmosphere causes a more widespread warming. ... More importantly, the researchers' model predicts that the increased water vapor would melt more sea ice, resulting in more absorption of sunlight by the open ocean and dumping more water vapor into the atmosphere. This positive feedback will warm the land even more and encourage faster, more efficient tree growth and perhaps a faster expansion of trees into the Arctic.

All told, the model predicts an additional 1 degree Celsius increase in temperature over the Arctic as a result of this effect. Global warming already is predicted to increase temperatures in the Arctic between 5 and 7 degrees Celsius within the next 100 years. The analysis was reported Jan. 7 in the online Early Edition of the journal Proceedings of the National Academy of Sciences.


Posted by Amanda Graham – 15 January 2010; 11:48:18 PM – Permalink  

Scientists say Canada's Arctic is for the birds

(Tom Spears, Canwest News Service, 14 January 2010) -- OTTAWA — Canadian scientists who slogged through wet tundra summer after summer think they've solved a puzzle: why millions of tiny shorebirds migrate from South America to the Arctic to nest. The answer is as old as parenthood. They do it for the kids.

It seems the farther north a sandpiper or curlew flies in spring, the better the chance that its eggs — laid on the ground — will escape foxes and hunting birds. The difference is enormous. High Arctic shorebirds suffer less than half as much loss to predators compared with birds around Hudson Bay, says the study in the journal Science.

"The Canadian Arctic supports huge numbers of the planet's shorebirds," says Grant Gilchrist, a biologist with Environment Canada and Carleton University in Ottawa, a member of the research team. "These birds are flying thousands of kilometres to reach their breeding grounds in the north." Why they don't just stop in Hudson Bay has always been the perplexing question, he says.


Posted by Amanda Graham – 15 January 2010; 11:34:28 PM – Permalink  

Ancient polar bear jaw found

(Svalbardposten, 7 January 2010) -- A polar bear jaw found on Prins Karls Forland in 2004 is the oldest fossil ever found of a polar bear. The researchers believe it may be up to 130,000 years old. The jaw was found in July 2004 by a group of geology students from UNIS, under the leadership of Professor Ólafur Ingólfsson. It was found on Pool Point on Prins Karls Forland, which is part of Forlandet National Park. Finding polar bear fossils, according to UNIS on their website, is something you do very rarely. One of the explanations is that polar bears live most of their lives on the ice, where they usually also die. Therefore, there is not much knowledge about the evolution of the polar bear in its history.

Research at Lund University in Sweden shows that the jaw is probably between 110,000 and 130,000 years old. That makes it the oldest fossil of a polar bear ever found, according to an article that was recently published by Professor Ólafur Ingólfsson, who works at the University of Iceland and UNIS, and Professor Øystein Wiig, University of Oslo. Scientists initially believed that the jaw came from a female bear, but after doing more analysis, it is evident now that it probably is from a full-grown male, with the same size as the male bears today. The jaw is well preserved, allowing for the possibility of further analysis of the fossil. Studies may be able to reveal more details about the evolutionary history of the polar bear. According Ingólfsson, this work has already started.


Posted by Amanda Graham – 13 January 2010; 12:08:26 AM – Permalink  

Northern forests do not benefit from lengthening growing season

(University of Helsinki press release via EurekAlert, 12 January 2010) -- Forests in northern areas are stunted, verging on the edge of survival. It has been anticipated that climate change improves their growth conditions. A study published last week in Forest Ecology and Management journal shows that due to their genetic characteristics trees are unable to properly benefit from the lengthening growing season. Furthermore, the researchers were surprised to find that the mortality of established trees considerably promotes the adaptation of forests to the changing environment. In cooperation with colleagues at the Universities of Oulu and Potsdam, Anna Kuparinen, Docent at the University of Helsinki's Faculty of Biological and Environmental Sciences, simulated forest growth from southern to northern Finland.

A meteorological dispersal model was applied to describe the spread of pollen and seeds in the atmosphere. Above all, the results illustrate the slowness of the adaptation process. Generally, trees stop growing before the frosts and this cessation of growth has been programmed in their genotype. Therefore, trees are unable to effectively follow the increasing environmental growing season. Instead, they cease growth as dictated by their genotype. It is estimated that after hundred years from now northern forests will substantially lag behind the speed of growth that would be enabled by their environment.

Evolution is promoted by the mortality of established trees The researchers assumed that demographic characteristics of the trees would have a notable impact on their adaptability. Tree species differ for example so that birch matures at a considerably younger age than pine, and birch seeds spread more effectively than pine seeds. However, the results showed that these differences had only minor impacts. Instead, the mortality of established trees played a large role in the evolutionary adaptation. The existing trees in northern forests will survive in a warmer climate better than before but, at the same time, they prevent genetically better adapted individuals from becoming more common. In a dense stand, old trees cast a shadow and prevent new seedlings from establishing. In this way, younger seedlings, which would be more suitable to warmer conditions, cannot easily progress beyond the sapling state.


Posted by Amanda Graham – 12 January 2010; 10:58:36 PM – Permalink  

Feedback accelerates Arctic ice melt — Canada, Alaska most pronounced

(Thomas Schueneman/ENN, 10 January 2010) -- Scientists at NASA and the National Snow and Ice Data Center published research last week in the Journal of Geophysical Research based on satellite microwave data of seasonal Arctic ice thaw from 1970 to 2009. The study indicates the seasonal Arctic sea ice melt melt season is now about 20 days longer than it was 30 years ago. The growing season of thaw is most pronounced in Arctic waters off the coasts of Alaska and Canada, including the Chukchi and Beaufort seas, where the season is 30 days longer now than in 1979. East Greenland and the Hudson Bay also share nearly a month longer of seasonal melt. The Hudson Bay exhibits one of the fastest increases in seasonal melt on the globe.

On average, seasonal melt has increased about 2.5 days per decade and lasts 3.7 days longer — an average of just under 20 days since 1979. "With the exception of the Sea of Okhotsk, all areas in the Arctic show a trend toward earlier melt onset and also a trend toward later freezeup," researchers said in their published report. Scientists suggest that the longer melt season creates a feedback loop further accelerating warming in the region. When the ice melts, darker ocean water absorbs more heat from the sun. With a longer melt season there is more time for these dark waters to absorb more heat, adding further to ice loss. The delayed fall freeze also means thinner ice reforms every season, leading to increased ice loss in the coming thaw next season.

NASA has recently published research showing that average thickness of Arctic sea ice shrank 2.2 feet between the winters of 2004 and 2008, with the surface area covered by multi-year ice shrinking by more than 42 percent.


Posted by Amanda Graham – 12 January 2010; 2:12:51 PM – Permalink  

Arctic terns' flying feat: same as 3 trips to Moon

(Alister Doyle/Reuters Environment, 11 January 2010) -- Arctic terns can fly more than 80,000 km (49,700 miles) a year, beating past estimates of the seabirds' record migrations and equivalent to three round trips to the Moon over a lifetime, a study showed on Monday. Tiny tracking devices attached to 11 of the small white birds breeding in Greenland or Iceland showed they flew a far more meandering route than expected on their annual trips to the Antarctic and back, an international team of scientists said. Already widely reckoned to have the longest migration of any creature, the birds flew an average of 70,900 km in a year, with one clocking up 81,600 km. That was double the 40,000 km often estimated in the past. And over a tern's lifetime of up to 34 years, the migrations add up to about 2.4 million km -- equivalent to three return trips to the Moon or a dizzying 60 times around the Earth.

"This is a mind-boggling achievement for a bird of just over 100 grams," said Carsten Egevang of the Greenland Institute of Natural Resources and lead author of the study with experts in Denmark, the United States, Britain and Iceland. "Tracking of Arctic terns...reveals longest animal migration," the scientists wrote in the U.S. journal Proceedings of the National Academy of Sciences. Other birds, such as albatrosses or sooty shearwaters, also have massive migrations.

Terns breed around the Arctic, from Iceland to Alaska, and exploit rich summertime fisheries for shrimp-like krill, other plankton and small fish in both polar regions. They escape freezing dark polar winters with their marathon flights. Egevang told Reuters that one surprise was that the Greenland and Iceland terns paused for a month or so to stock up on food in the Atlantic on their way south in August. Some birds then flew south past Africa, others close to South America.


Posted by Amanda Graham – 11 January 2010; 2:39:07 PM – Permalink  

Melting tundra creating vast river of waste into Arctic Ocean

(ScienceDaily, 11 January 2010) -- The increase in temperature in the Arctic has already caused the sea-ice there to melt. According to research conducted by the University of Gothenburg, if the Arctic tundra also melts, vast amounts of organic material will be carried by the rivers straight into the Arctic Ocean, resulting in additional emissions of carbon dioxide. Several Russian rivers enter the Arctic Ocean particularly in the Laptev Sea north of Siberia. One of the main rivers flowing into the Laptev Sea is the Lena, which in terms of its drainage basin and length is one of the ten largest rivers in the world. The river water carries organic carbon from the tundra, and research from the University of Gothenburg shows that this adds a considerable amount of carbon dioxide to the atmosphere when it is degraded in the coastal waters.

The increase in temperature in the Arctic, which has already made an impact in the form of reduced sea-ice cover during the summer, may also cause the permafrost to melt. "Large amounts of organic carbon are currently stored within the permafrost and if this is released and gets carried by the rivers out into the coastal waters, then it will result in an increased release of carbon dioxide to the atmosphere," says Sofia Hjalmarsson, native of Falkenberg and postgraduate student at the Department of Chemistry.


Posted by Amanda Graham – 11 January 2010; 2:33:07 PM – Permalink  

Melt season for Canadian Arctic sea ice outpacing global average: study

(Bob Weber/Canadian Press via Winnipeg Free Press, 6 January 2010) -- American researchers suggest the melting season for Arctic sea ice is growing faster across much of the Canadian Arctic than anywhere else in the world.

A recently published article outlines how they used satellite microwave data to measure when sea ice begins to melt in the spring and when it starts refreezing in the fall. The researchers were able to look with 99 per cent accuracy as far back as 1979 and examine the entire circumpolar globe, the first time scientists have been able to do so. They found that, on average, sea ice has started melting 2.5 days earlier every decade and begun to refreeze 3.7 days later.

That means the average melt season is just under 20 days longer than it was 30 years ago. "All areas in the Arctic show a trend toward earlier melt onset and also a trend toward later freeze-up," says the paper, published in the latest Journal of Geophysical Research. However, the melt period for ice in several areas of the Canadian Arctic is growing even faster. In Baffin Bay, at the eastern gate of the Northwest Passage, it is increasing about 20 per cent faster than the global average. And in the Beaufort Sea and Hudson Bay, the melt period is now a full month longer than it was in 1979.

In fact, the melting season for Hudson Bay ice is increasing at one of the fastest paces in the world, probably because it's one of the most southerly ice packs. The only Canadian melt period increasing at the global average was found in ice tucked in between the High Arctic islands. The study couldn't answer why the Canadian ice melt periods were growing faster than some in Russian waters.


Posted by Amanda Graham – 6 January 2010; 10:28:27 PM – Permalink  

Research report foresees no 'armed mad dash for resources' in the Arctic

With climate change making the Arctic gradually more accessible, some observers have suggested that interest in Arctic natural resources and disputed marine borders could take on a military aspect. A new study by researchers of the Fridtjof Nansens Institute (FNI) in Norway refutes this view, finding that dispassionate diplomacy is a more likely and rational way of dispute resolution than military confrontation.

"Contrary to the general picture drawn by the media and some commentators over the last couple of years, the Arctic region does not suffer under a state of virtual anarchy. The era when states could claim rights to territory and resources by simply planting their flag is long gone," says a law of the sea expert Øystein Jensen, one of researchers behind the study. He refers to the 2007 Arktika expedition that planted a Russian flag into the seabed below the North Pole point, an event which raised concerns in Arctic capitals, and sparked off a round of media reports on an "Arctic race for territory and resources."

"The basic fact here is that the Arctic Ocean is an ocean, and as such, regulated by the law of the sea. Previous tendencies to question the legal status of the Arctic Ocean as a sea area -- due to it being predominantly ice-covered -- stand no chance of being accepted today. At the outset, there is thus no support in international law to treat the waters of the frozen North differently from other maritime spaces," Jensen stresses. Ref: Øystein Jensen, Svein Vigeland Rottem. The politics of security and international law in Norway's Arctic waters. Polar Record, 2010; 46 (1): 75 DOI: 10.1017/S0032247409990076 Article information


Posted by Amanda Graham – 5 January 2010; 12:57:29 PM – Permalink  

Loss of sea ice stirs up Arctic waters

(AGU press release via ScienceDaily, 4 January 2010) -- The Arctic Ocean is generally considered a remarkably quiet ocean, with very little mixing, because a cover of sea ice prevents wind from driving the formation of internal waves. To study this effect and investigate how melting sea ice might affect ocean mixing in the Arctic, Rainville and Woodgate analyze data from moorings in the northern Chukchi Sea. They find that when the ocean was mostly covered with ice, even strong winds did not generate much response in it.

On the other hand, during the summers when less sea ice was present, wind generated large internal oscillations and increased turbulence. The extent of Arctic sea ice in the summer has been declining significantly in recent years, likely resulting in increased internal wave generation, the authors note. Because internal waves bring deeper waters closer to the surface, the results have important implications for Arctic Ocean ecosystems and ocean dynamics. The research is published in Geophysical Research Letters. Authors include Luc Rainville and Rebecca A. Woodgate: Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.


Posted by Amanda Graham – 3 January 2010; 9:57:39 PM – Permalink  

Updated count of Pacific walrus posted [mp3]

(Annie Feidt/APRN Anchorage, 30 December 2009) -- The US Fish and Wildlife Service is out with an updated count for Pacific Walrus.  The agency estimates there are a minimum of 129,000 animals in the population, but says the new number can’t be compared to past counts. The massive undertaking was a collaboration between the US and Russia.


Posted by Amanda Graham – 31 December 2009; 10:57:09 AM – Permalink  ann-20091230-01.mp3

Arctic Ocean’s ice-free past may shed light on 2100, study says

(Alex Morales/Bloomberg, 30 December 2009) -- Evidence that the Arctic Ocean was ice-free 3 million years ago, when average global temperatures were similar to projections for 2100, may shed light on how the far north will change as the Earth warms, a U.S. scientist said. Fossilized shells recovered from the seabed show the Arctic Ocean was ice-free for at least part of the year during the mid- Pliocene era about 3 million to 3.3 million years ago, U.S. Geological Survey researcher Marci Robinson said in the journal Stratigraphy. The average temperature globally was about 3 degrees Celsius (5.5 degrees Fahrenheit) warmer than today, in line with United Nations forecasts for 2100, she said.

The USGS scientist said the findings can be used to refine predictions of ice melt, after sea ice in 2007 shrank to the lowest extent on record. An ice-free Arctic would open up new shipping routes and ease access to undersea mineral resources, and companies including Royal Dutch Shell Plc and BP Plc are stepping up exploration for oil and gas off Alaska and Canada.

“The lack of summer sea ice during the mid-Pliocene suggests that the record-setting melting of Arctic sea ice over the past few years could be an early warning of more significant changes to come,” Robinson said in an e-mailed statement. Effects of losing sea ice could include enhanced coastal erosion in the Arctic due to increased wave activity and harm to wildlife including polar bears and seals. Other possible changes include more winter precipitation in western and southern Europe and less rainfall in the U.S. West, the researcher said.


Posted by Amanda Graham – 31 December 2009; 9:43:45 AM – Permalink  

North magnetic pole moving due to core flux

(Richard A. Lovett/National Geographic News, 24 December 2009) -- Earth's north magnetic pole is racing toward Russia at almost 40 miles (64 kilometers) a year due to magnetic changes in the planet's core, new research says. The core is too deep for scientists to directly detect its magnetic field. But researchers can infer the field's movements by tracking how Earth's magnetic field has been changing at the surface and in space.

Now, newly analyzed data suggest that there's a region of rapidly changing magnetism on the core's surface, possibly being created by a mysterious "plume" of magnetism arising from deeper in the core. And it's this region that could be pulling the magnetic pole away from its long-time location in northern Canada, said Arnaud Chulliat, a geophysicist at the Institut de Physique du Globe de Paris in France.

Magnetic north, which is the place where compass needles actually point, is near but not exactly in the same place as the geographic North Pole. Right now, magnetic north is close to Canada's Ellesmere Island. Navigators have used magnetic north for centuries to orient themselves when they're far from recognizable landmarks. Although global positioning systems have largely replaced such traditional techniques, many people still find compasses useful for getting around underwater and underground where GPS satellites can't communicate.

The magnetic north pole had moved little from the time scientists first located it in 1831. Then in 1904, the pole began shifting northeastward at a steady pace of about 9 miles (15 kilometers) a year. In 1989 it sped up again, and in 2007 scientists confirmed that the pole is now galloping toward Siberia at 34 to 37 miles (55 to 60 kilometers) a year. A rapidly shifting magnetic pole means that magnetic-field maps need to be updated more often to allow compass users to make the crucial adjustment from magnetic north to true North. [See also Brian Vastag, "North Magnetic Pole is Shifting Rapidly Toward Russia," National Geographic News, 15 December 2009.]


Posted by Amanda Graham – 31 December 2009; 9:41:06 AM – Permalink  

Permafrost thaw may accelerate Arctic groundwater runoff

(American Geophysical Union press release via ScienceDaily, 31 December 2009) -- As the Arctic warms, permafrost will degrade, potentially resulting in increased groundwater runoff as frozen ground that had blocked the flow of water melts. To investigate how groundwater systems will evolve as surface temperatures rise, Bense et al., developed a model to simulate an idealized aquifer covered by a layer of permafrost. The authors found that although the initial distribution of ice influences the response, in all cases groundwater flow to streams and rivers accelerates over time. In fact, the results indicate that substantial increases in groundwater flow are likely over the next few centuries even if surface air temperatures stabilize at current levels. The research is published in Geophysical Research Letters.


Posted by Amanda Graham – 30 December 2009; 10:32:06 PM – Permalink  

Mysterious collapse of reindeer herd blamed on freak storms

(Alexis Madrigal/Wired Science 17 December 2009) -- SAN FRANCISCO — On a remote island in the Bering Strait during World War II, a tiny band of Americans ran a radar station. Twenty-nine reindeer were placed on St. Matthew Island with them, to be eaten in case of emergency. The emergency never came, and population biologist Dave Klein counted 6,000 reindeer on the island by 1963, spread out over just 50 square miles of land. Then, sailors started to report seeing bleached reindeer skeletons dotting the island. When Klein returned in 1966, there were only 42 left and no males with the ability to reproduce. The herd dwindled and eventually went extinct.

There this strange mystery sat for decades until extreme weather specialist John Walsh of the University of Alaska-Fairbanks and University of Nebraska climatologist Martha Shulski teamed up with the now 80-year-old Klein to solve it. They announced their findings this week here at the American Geophysical Union meeting. It turns out that a series of winter cyclones comparable in intensity to a Category 2 hurricane buffeted the island in early 1964. Overpopulated and isolated as the island was, the reindeer herd proved vulnerable to the extreme storms, which brought much heavier than normal snowfall, stronger winds, and lower temperatures.

The question that remains is why these extra-strong storms occurred. For reasons that still aren’t understood, a series of weather systems sweeping across the Pacific from Japan intensified just east of the dateline and then headed north. Over that winter, the closest weather station to reindeer’s home, St. Paul Island, got more than six and a half feet more snow than normal. The barometric pressure differential between the low of the strongest storm and the regional high in Siberia was the highest in the 60-year period for which measurements are available. The reindeer were no match.


Posted by Amanda Graham – 29 December 2009; 12:46:56 PM – Permalink  

Arctic could face warmer and ice-free conditions

(United States Geological Survey press release, 29 December 2009) -- There is increased evidence that the Arctic could face seasonally ice-free conditions and much warmer temperatures in the future. Scientists documented evidence that the Arctic Ocean and Nordic Seas were too warm to support summer sea ice during the mid-Pliocene warm period (3.3 to 3 million years ago). This period is characterized by warm temperatures similar to those projected for the end of this century, and is used as an analog to understand future conditions.

The U.S. Geological Survey found that summer sea-surface temperatures in the Arctic were between 10 to 18°C (50 to 64°F) during the mid-Pliocene, while current temperatures are around or below 0°C (32°F). Examining past climate conditions allows for a true understanding of how Earth's climate system really functions. USGS research on the mid-Pliocene is the most comprehensive global reconstruction for any warm period. This will help refine climate models, which currently underestimate the rate of sea ice loss in the Arctic. Loss of sea ice could have varied and extensive consequences, such as contributions to continued Arctic warming, accelerated coastal erosion due to increased wave activity, impacts to large predators (polar bears and seals) that depend on sea ice cover, intensified mid-latitude storm tracks and increased winter precipitation in western and southern Europe, and less rainfall in the American west.

"In looking back 3 million years, we see a very different pattern of heat distribution than today with much warmer waters in the high latitudes," said USGS scientist Marci Robinson. "The lack of summer sea ice during the mid-Pliocene suggests that the record-setting melting of Arctic sea ice over the past few years could be an early warning of more significant changes to come." Global average surface temperatures during the mid-Pliocene were about 3°C (5.5°F) greater than today and within the range projected for the 21st century by the Intergovernmental Panel on Climate Change. Read the full article at http://micropress.org/stratigraphy/


Posted by Amanda Graham – 29 December 2009; 12:29:04 PM – Permalink  

Aviation contributes up to one-fifth of warming in some areas of the Arctic

(Rex Dalton/NatureNews, doi:10.1038/news.2009.1157, 21 December 2009) -- The first analysis of emissions from commercial airline flights shows that they are responsible for 4–8% of surface global warming since surface air temperature records began in 1850—equivalent to a temperature increase of 0.03–0.06 °C overall.

The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapour trails produced 15–20% of warming. ... Previous studies have only estimated the impacts of commercial aviation, but this is the first use of actual emissions data—from 2004 and 2006—to calculate warming from such flights, says Mark Jacobson, a Stanford engineer who presented the analysis on 17 December at the American Geophysical Union's annual meeting in San Francisco, California.


Posted by Amanda Graham – 23 December 2009; 11:50:35 AM – Permalink  

Northern Lights burst captured on film

(UPI.com, 18 December 2009) -- LOS ANGELES - Cameras for the first time have filmed waves of aurora borealis colliding to produce spectacular bursts of light, scientists in California said. "Our jaws dropped when we saw the movies for the first time. These outbursts are telling us something very fundamental about the nature of auroras," space scientist Larry Lyons of the University of California, Los Angeles, said in a release Thursday.

The images have been captured since December 2007 by a network of NASA cameras spread across thousands of miles around the Arctic. Each burst of light was preceded by a broad wave, or curtain, of slow-moving auroras and a smaller knot of fast-moving auroras, initially far apart. The slow curtain hung almost immobile while the fast-moving knot rushed in from the north to collide with the slow curtain and produce a blast of light. The collisions occurred on such a vast scale that isolated observers, with limited fields of view, had never noticed them before, said Lyons, who led the expedition team. Movies of the phenomenon were shown Thursday at the meeting of the American Geophysical Union in San Francisco.


Posted by Amanda Graham – 19 December 2009; 11:15:09 PM – Permalink  

NASA takes a rare look at warming Arctic

(NASA press release via PRNewswire-USNewswire via Yahoo! News, 15 December 2009) -- HAMPTON, Va. - A NASA field campaign to study man-made and natural influences on the Arctic atmosphere delivered a collection of rare data that is illuminating the impact of industrial pollution from Europe and Asia, and smoke and soot from agricultural and forest fires. NASA's first in-depth airborne campaign to sample the Arctic atmosphere in years, the Atmospheric Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission took place in the spring and summer of 2008. It was the first in-depth airborne campaign to sample the Arctic atmosphere in years beginning in cooperation with NOAA, the Department of Energy, and international agencies as part of the International Polar Year.

Scientists from NASA and a number of universities will be presenting their ARCTAS research results from the campaign during the American Geophysical Union's fall meeting in San Francisco from Dec. 14-18. Aircraft observations revealed a stronger influence of Asian pollution than previously thought and saw smoke plumes travel to the Arctic from great distances. While ground-based instruments and satellites make routine measurements, these up-close airborne measurements provide a more finely resolved look at the changing chemistry of the Arctic, the most rapidly warming region on Earth. "For scientists interested in studying the role of changing atmospheric composition on climate, the ARCTAS data will represent the best and often only detailed information available for this poorly characterized region," said Jim Crawford, a research scientist at NASA's Langley Research Center and the ARCTAS program manager during the campaign.


Posted by Amanda Graham – 15 December 2009; 10:11:26 PM – Permalink  

Portions of Arctic coastline eroding, no end in sight, says new study

(University of Colorado at Boulder press release, 15 December 2009) -- The northern coastline of Alaska midway between Point Barrow and Prudhoe Bay is eroding by up to one-third the length of a football field annually because of a "triple whammy" of declining sea ice, warming seawater and increased wave activity, according to new study led by the University of Colorado at Boulder. The conditions have led to the steady retreat of 30 to 45 feet a year of the 12-foot-high bluffs—frozen blocks of silt and peat containing 50 to 80 percent ice—which are toppled into the Beaufort Sea during the summer months by a combination of large waves pounding the shoreline and warm seawater melting the base of the bluffs, said CU-Boulder Associate Professor Robert Anderson, a co-author on the study. Once the blocks have fallen, the coastal seawater melts them in a matter of days, sweeping the silty material out to sea.

Anderson, along with collaborators Cameron Wobus of Stratus Consulting and Irina Overeem of CU's Institute of Arctic and Alpine Research, or INSTAAR, each presented results from components of their study at the annual meeting of the American Geophysical Union in San Francisco held Dec. 14-18. The problem is caused by several factors, including increased erosion along the Alaskan coastline due to longer ice-free summer conditions and warmer seawater bathing the coast, Anderson said. The third potential factor is that the longer the sea ice is detached from the coastline, the further out to sea the sea-ice edge will be. This open-ocean distance between the sea ice and the shore, known as the "fetch," increases both the energy of waves crashing into the coast and the height to which warm seawater can come into contact with the frozen bluffs, said Anderson.


Posted by Amanda Graham – 15 December 2009; 8:42:17 PM – Permalink  

Climate change in Arctic could bring Pacific mollusks, other species to Atlantic

(Krista Armstrong/CP via Google News, 13 December 2009) -- HALIFAX, N.S. — Mollusks from the Pacific could march into the Atlantic Ocean within decades because of the melting of Arctic sea ice, researchers in California say. For mollusks to pass, the Arctic would need to have less than 75 per cent sea-ice cover for 125 consecutive days—something that could happen around 2050, according to an estimate two years ago by the Intergovernmental Panel on Climate Change. But Peter Roopnarine, curator of geology and paleontology at the California Academy of Sciences in San Francisco, says that could happen sooner.

"We could be looking at between 2020 and 2030," says Roopnarine, who based his prediction on models of climate change within the last three years. Roopnarine and Geerat Vermeij, a geologist and evolutionary biologist at the University of California, Davis, say Pacific-to-Atlantic migration is probable for all kinds of sea life, including fish, crabs, sea stars, sea urchins and seaweed.

They base much of their theory, which first appeared in the scientific journal Science last year, on fossil records from the last time mollusks traversed the Arctic: about 3.5 million years ago. At the time there was a shift in climate, which kept the Bering Strait open long enough to allow hundreds of species, such as mollusks, cod and herring, to migrate from the Pacific to the Atlantic over the ice-free Arctic. Some of the species became extinct, but others colonized the Atlantic and continue to populate its waters today.

Roopnarine says a similar phenomenon is in the offing. "A lot of fish, for example, are certainly going to be part of this invasion," he says. "It's going to change the entire composition of the Northwest Atlantic ecosystem."


Posted by Amanda Graham – 14 December 2009; 1:09:53 AM – Permalink  

Barents Sea affected by climate changes

(Barents Observer, 8 December 2009) -- The first joint Norwegian-Russian report on the Barents Sea Ecosystem raises concerns about sea mammals’ reproduction due to the ongoing climate changes.  The report was initiated by the Joint Russian-Norwegian Commission on Environmental Cooperation and the work has been carried out in co-operation with the Joint Russian-Norwegian Fisheries Commission. The main objective was to provide a comprehensive description of the Barents Sea ecosystem using relevant scientific knowledge from both Russian and Norwegian scientists. More than 130 experts from a total of nine Russian and 20 Norwegian institutions have participated. The work has been led by Sevmorgeo and PINRO on the Russian side and Institute of Marine Research and the Norwegian Polar Institute on the Norwegian side.

In general, the report describes a healthy ecosystem in the Barents Sea. Much of the illegal fishing is ended and the fish stocks are in sustainable conditions. The ocean is relatively little polluted, but receives long-range transboundary transported pollution through both atmospheric and oceanic advection. In particular, the level of PCBs and other persistent organic pollutants as well as some inorganic contaminants worries the scientists. Among species high up in the food chain the levels are considerable. Especially polar bear and some sea birds are exposed to high levels of toxics. In addition, climatic changes have considerable effects on the system. Reproductive failure and negative population trends in ice-dependent marine mammals are possible effects of climate change, the report writes. Ocean acidification caused by anthropogenic emission of CO2 is an emerging problem that might have a large impact on the Barents Sea ecosystem in the future, according to the joint Norwegian-Russian report.


Posted by Amanda Graham – 13 December 2009; 5:15:32 PM – Permalink  

Study reveals how Arctic food webs affect mercury in polar bears

(University of Michigan press release via EurekAlert! 8 December 2009) -- ANN ARBOR, Mich. - With growing concerns about the effects of global warming on polar bears, it's increasingly important to understand how other environmental threats, such as mercury pollution, are affecting these magnificent Arctic animals. New research led by biogeochemists Travis Horton of the University of Canterbury and Joel Blum of the University of Michigan lays the groundwork for assessing current and future effects of mercury deposition and climate change on polar bears. The study appears in the December issue of the journal Polar Research.

Mercury is a naturally occurring element, but some 150 tons of it enter the environment each year from human-generated sources such as coal-burning power plants, incinerators and chlorine-producing plants. Deposited onto land or into water, mercury is picked up by microorganisms, which convert some of it to methylmercury, a highly toxic form that builds up in fish and the animals that eat them. As bigger animals eat smaller ones, the methylmercury is concentrated—a process known as bioaccumulation.

Sitting at the top of the food chain, polar bears amass high concentrations of the contaminant. Although that much is known, the details of how mercury moves through different food webs—particularly in the Arctic, where snow and ice contribute to mercury deposition—are not well understood. To tease out that information, Horton, Blum and co-workers studied polar bear hair samples from museum specimens collected in the late 19th and early 20th centuries, before mercury emissions from human-generated sources began to escalate.

By looking at three chemical signatures—nitrogen isotopes, carbon isotopes and mercury concentrations—the researchers learned that polar bears get their nutrition (and mercury) from two main food webs. At the base of one web are microscopic plants that float on the surface of the ocean (known as phytoplankton). The foundation of the second web is algae that live on sea ice. The study showed that polar bears that get most of their nutrition from phytoplankton-based food webs have greater mercury concentrations than those that participate primarily in ice algae-based webs.


Posted by Amanda Graham – 9 December 2009; 10:35:44 PM – Permalink  

U.S. scientists: warming Arctic not a pretty picture

(Jane George/Nunatsiaq News Online, 7 December 2009) -- COPENHAGEN - As sea ice on the Arctic Ocean thins and shrinks, Greenland’s ice sheet melts and seas turn acid, water temperatures will go up, sea levels rise, and marine life die, U.S scientists attending the COP15 gathering in Copenhagen said this week. The Arctic’s overall temperature has already risen by 3°C — much more than the half of a degree rise experienced globally. That’s the un-pretty picture painted by the scientists from the United States, who shared their most recent information about the Arctic’s melting ice at the United Nations climate change meeting in Copenhagen. The ice melt has gone so far that turning back to Arctic’s cold environment of the past may be “very hard,” the scientists said at the event, called “The Arctic: one of the earth’s most rapidly warming regions.” The scientists didn’t want to use the word “tipping point” to describe this situation of no return for the planet. But they said it would be impossible to turn around the warming processes that could leave the Arctic with no summer sea ice by 2050 at the latest, and with an ocean incapable of sustaining any marine life, from clams to whales. As the scientists spoke to a sparse audience in the U.S. government’s meeting room on the opening morning of the climate change conference, an overflow crowd watched Dr. Rajendra Pachauri, chairman of the United Nations’s Intergovernmental Panel on Climate Change, defend the science in the IPCC’s fourth assessment report in 2007, which also warned of disappearing ice. To keep climate change in check, Denmark’s environment minister, Connie Hedegaard, urged the 15,000 delegates at the UN climate change to compromise, agree, come up with concrete solutions and “mark this meeting in history.”


Posted by Amanda Graham – 8 December 2009; 11:57:38 AM – Permalink  

Sea lion survey finds one group increasing another declining

(Dan Joling/Anchorage Daily News, 6 December 2009) -- A count of Alaska's Steller sea lion pups indicates the state's two populations are headed in different directions for recovery. Pups in the eastern population, living along Alaska's Panhandle, are thriving.

 "The eastern stock has met its recovery criteria," said Lowell Fritz, a biologist at the National Marine Mammal Laboratory in Seattle. The population may even be close to removal from the threatened species list, he said. The western population, from Prince William Sound to the Aleutian Islands and the Bering Sea, continues to struggle.

"We expected to see the increased Steller sea lion numbers in Southeast Alaska again," said Doug DeMaster, director of the Alaska Fisheries Science Center in Seattle. "The mixed results in the western population, however, indicate that some areas have improved in numbers while others continue to decline, especially the western Aleutian Islands." Most of the world's sea lions live in Alaska. The western stock declined by 75 percent between 1976 and 1990, leading to their listing as endangered. Disease and contaminants have diminished as suspects, Fritz said. The decline likely was due to a combination of factors, including environmental changes, nutritional stress or changes in prey.

"We don't really know how to weight those," Fritz said. Federal, university and state researchers have spent millions trying to find out. Federal wildlife managers implemented no-fishing zones around rookeries and haulouts to enhance recovery, a move questioned by Alaska's commercial fishing industry.


Posted by Amanda Graham – 6 December 2009; 12:23:01 PM – Permalink  

Carbon and oxygen in tree rings can reveal past climate information

(Arctic Institute of North America press release, 3 December 2009) -- OTTAWA - The analysis of carbon and oxygen isotopes embedded in tree rings may shed new light on past climate events in the Mackenzie Delta region of northern Canada. Scientists have long looked at the width of tree rings to estimate temperature levels of past years. Larger rings indicate more tree growth in a season, which translates into warmer summer temperatures. But the analysis of carbon and oxygen isotopes in tree rings can also provide accurate data on past climate events, say researchers working in northern Canada. In a paper published in the most recent issue of the journal of Arctic, Antarctic and Alpine Research, Trevor Porter, a PhD student in Geography and Environmental Science at Carleton University, and three other authors compared temperature data collected in Inuvik, Northwest Territories (NT) since 1957 with their own analysis of isotopes found in white spruce trees in the Mackenzie Delta region of the NT. They found a strong correlation between the two data sets and temperatures.

"Isotope analysis is a good way to measure past climate change," says Porter about the results. Isotope analysis is not a new way to measure past air temperatures. However, the method has not been widely used because lab costs have been prohibitive, especially when compared with the examination of tree ring width. Now, however, the cost of equipment has dropped substantially making it more affordable for researchers to use this method. Porter's work was carried out on the northern edge of the boreal forest in the NT where trees are small but surprisingly old. "A 15 to 20 cm. tree could be a 300 to 400 year old tree," says Porter. This slow rate of growth actually helps researchers because smaller trees stay standing longer. Trees that fall begin to decay making data analysis difficult or impossible. "Once they get too large, it's difficult for trees to persist. They are susceptible to wind and ice storms. One of the reasons trees (in the North) persist so long is because they don't grow as much," says Porter. ...

Porter is hoping his work will lay the foundation for a model that can be used to investigate the long-term climate history of the Mackenzie Delta region. Although the temperature record for Inuvik only dates back to 1957, the dead and live tree ring record stretches to nearly 1000 years before present. That prospect excites the young researcher. "The tree ring record goes back almost a thousand years in this area, but it's never been used for a temperature reconstruction. This is a really exciting time to work in climate research, especially for a young student," he says adding, "This is a hot topic."


Posted by Amanda Graham – 5 December 2009; 6:13:32 PM – Permalink  

First comprehensive review of the state of Antarctica's climate

(British Antarctic Survey press release, 30 November 2009) -- The first comprehensive review of the state of Antarctica's climate and its relationship to the global climate system is published this week (Tuesday 1 December) by the Scientific Committee on Antarctic Research (SCAR). The review—Antarctic Climate Change and the Environment—presents the latest research from the icy continent, identifies areas for future scientific research, and addresses the urgent questions that policy makers have about Antarctic melting, sea-level rise and biodiversity. Based on the latest evidence from 100 world-leading scientists from 13 countries, the review focuses on the impact and consequences of rapid warming of the Antarctic Peninsula and the Southern Ocean; rapid ice loss in parts of Antarctica and the increase in sea ice around the continent; the impact of climate change on Antarctica's plants and animals; the unprecedented increase in carbon dioxide levels; the connections between human-induced global change and natural variability; and the extraordinary finding that the ozone hole has shielded most of Antarctica from global warming. ...

Professor John Turner of British Antarctic Survey is the lead editor of the review. He said, " For me the most astonishing evidence is the way that one man-made environmental impact—the ozone hole—has shielded most of Antarctica from another—global warming. Understanding the complexities surrounding these issues is a challenge for scientists—and communicating these in a meaningful way to society and to policymakers is essential. There is no doubt that our world is changing and human activity is accelerating global change. This review is a major step forward in making sure that the latest and best evidence is available in one place. It sets the scene for future Antarctic Research and provides the knowledge that we all need to help us live with environmental change." [See the 10 main findings in the original press release.]


Posted by Amanda Graham – 1 December 2009; 11:27:43 AM – Permalink  

Swedish archaeologists celebrate ancient find

(The Local, 29 November 2009) -- People lived in the Torne River Valley on the border with Sweden and Finland some 11,000 years ago, an important new archaeological find has shown. The settlement, found near Pajala in the far north of Sweden, are the oldest known find in the county of Norrbotten, according to the archaeologist Olof Östlund. The find was uncovered when archaeologists were searching for ancient remains in the area around Kaunisvaar near Pajala where a new mine is set to open, according to a report in local newspaper Norrländska Socialdemokraten.

"Now the pages in the National Encyclopaedia regarding inland ice can be torn out and burned," Östlund told the newspaper. The archaeologists located the settlements in the beginning of September and they have now been dated with the help of radiocarbon dating. "I had been expecting old dates. But when I saw that the first numbers were very high I felt immediately that this was bingo. When the second number was five figures—I felt faint," Östlund explained to news agency TT. He was surprised that the find was so old and compared it to another settlement located nearby in Kangofors five years ago. That settlement had been used 10,000 years ago.

The survey was conducted on commission from a company prospecting for mines in the vicinity of Pajala and will shed light on the first inhabitants of Norrbotten. "So this is important. Especially as in archaeological circles, in southern Sweden, the accepted theory is that there was no ancient age up here in northern Sweden it is thus important to raise the issue." Östlund compared the new discovery to the find in Voullerim in the middle of the 1980s of 6,000 year-old stone age shelters. Then the assumptions regarding the history of the pre-history of Norrland were revalued to take into account that people had actually lived there. Archaeologists were also then given new types of remains to look for—and several finds were then later uncovered. See also Irish Sun, "Polar ice cap during last Ice Age may not have been as extensive as previously thought,"30 November 2009).


Posted by Amanda Graham – 30 November 2009; 1:07:13 AM – Permalink  

GW researcher moves closer to understanding cause of mass extinction

(George Washington University press release, 24 November 2009) -- WASHINGTON – Years of scientific debate over the extinction of ancient species in North America have yielded many theories. However, new findings from J. Tyler Faith, GW Ph.D. candidate in the hominid paleobiology doctoral program, and Todd Surovell, associate professor of anthropology at the University of Wyoming, reveal that a mass extinction occurred in a geological instant. During the late Pleistocene, 40,000 to 10,000 years ago, North America lost over 50 percent of its large mammal species. These species include mammoths, mastodons, giant ground sloths, among many others. In total, 35 different genera (groups of species) disappeared, all of different habitat preferences and feeding habits.

What event or factor could cause such a mass extinction? The many hypotheses that have been developed over the years include: abrupt change in climate, the result of comet impact, human overkill and disease. Some researchers believe that it may be a combination of these factors, one of them, or none. A particular issue that has also contributed to this debate focuses on the chronology of extinctions. The existing fossil record is incomplete, making it more difficult to tell whether or not the extinctions occurred in a gradual process, or took place as a synchronous event. In addition, it was previously unclear whether species are missing from the terminal Pleistocene because they had already gone extinct or because they simply have not been found yet.

However, new findings from Faith indicate that the extinction is best characterized as a sudden event that took place between 13.8 and 11.4 thousand years ago. Faith’s findings support the idea that this mass extinction was due to human overkill, comet impact or other rapid events rather than a slow attrition. ... The article, "Synchronous Extinction of North America's Pleistocene Mammals" appears in the Nov. 23 edition of Proceedings of the National Academy of Sciences.


Posted by Amanda Graham – 29 November 2009; 11:05:43 AM – Permalink  

Climate 'time bombs' stoke scientists' fears

(Marlowe Hood/AFP, 29 November 2009)—PARIS — Whatever the outcome of the UN climate summit in Copenhagen, Nature may have some extremely nasty surprises up its sleeve, say scientists. They say Earth's biosphere has numerous "tipping points"—triggers that cause global warming and its impacts to lurch up a gear or two, rather than occur in a smooth, incremental way. In other words, the planet itself would become the main driver of warming, making the crisis far more difficult to manage. Many of the tipping points have only been discovered within the last decade or so, and experts admit to many unknowns as to how and when they could occur.

Here is a summary of the main triggers, outlined by the UN's Intergovernmental Panel on Climate Change (IPCC) and in studies published in peer-reviewed journals: The Arctic ice cap, which in winter covers some 15 million square kilometres (5.8 million square miles), is shrinking. Whether the region's first ice-free summer happens in five years or 50 is only a matter of 'when', not 'if', many scientists say. ... Since 2000, though, Greenland has lost 1,500 billion tonnes of ice, contributing 0.75 mm (0.03 inch) annually to sea levels, and some scientists fear it could collapse within a couple of centuries. ...

Locked inside permafrost, covering a fifth of Earth's land surface, are billions of tonnes of carbon in the form of methane, a greenhouse gas 30 times more potent than CO2. The top three metres (10 feet) of this frozen landscape—up to a kilometre (half-mile) thick—contain as much carbon as Earth's atmosphere. As temperatures rise, more and more methane is freed and enters the atmosphere, adding to the greenhouse effect. ...

More than half the CO2 humans generate is absorbed, in roughly equal measure, by forests and oceans. Earth's plant life is so far keeping pace with emissions despite tropical deforestation. But oceans are showing signs of fatigue, according to a study released last week by the Global Carbon Project (GCP), an international consortium of climate scientists.

Over the last half century, the percentage of CO2 pumped into the atmosphere that stays there has gone up from 40 to 45 percent, fuelling the greenhouse effect. Part of the decrease may be due to carbon saturation and rising emissions. But rising temperatures also cause ocean acidification, hampering the ability of marine organisms—plankton, algae, coral—to transform CO2 into calcium-rich shells that help to lock away carbon for millennia.


Posted by Amanda Graham – 29 November 2009; 10:55:25 AM – Permalink  

Hungry polar bears eat young due to shrinking sea ice: scientists

(CP via GoogleNews, 28 November 2009) -- Scientists say shrinking Arctic sea ice may be forcing some hungry polar bears to cannibalize bear cubs. At least seven cases of mature male polar bears eating bear cubs have been spotted this year among the animals around Churchill, Man. Ian Stirling, a retired Environment Canada biologist who specializes in the Churchill bears, calls it the highest incidence of cannibalization he has ever seen. Stirling says evidence suggests the cubs are being killed for food, not just so the male can mate with the sow. He says the Hudson Bay sea ice, which the bears use to get at the seals they need to fatten up for winter, isn't appearing until weeks later than it used to.

Posted by Amanda Graham – 28 November 2009; 12:05:57 PM – Permalink  

Canadian researcher says arctic ice is thinning

(AP, 28 November 2009) -- WINNIPEG, Manitoba - The permanent Arctic sea ice that is home to the world's polar bears and usually survives the summer has all but disappeared, a Canadian researcher said Friday. University of Manitoba Arctic researcher David Barber said experts around the world believed the ice was recovering because satellite images showed it expanding, but the thick, multiyear frozen sheets have been replaced by thin ice that cannot support the weight of a polar bear.

"Polar bears are being restricted to a small fringe of where this multiyear sea ice is. As we went further and further north, we saw less and less polar bears because this ice wasn't even strong enough for the polar bears to stand on," said Barber, who just returned from an expedition to the Beaufort Sea. The deterioration has far-reaching consequences for the North and its iconic mammal. Polar bears that rely on the permanent ice to survive the summer have fewer and fewer places of refuge, Barber said.

The researcher said permanent ice, which is normally up to 10 meters (30 feet) thick, was easily pierced by the research ship. The team finally reached what it thought was stable ice, only to watch a crack appear just as researchers were preparing to descend onto the floe. "As I watched, over the course of five minutes, the entire multiyear ice floe broke up into pieces. This floe was 10 miles across," said Barber, who holds the Canada research chair in Arctic science at the University of Manitoba. Ten miles equal about 16 kilometers. The ice is unable to withstand battering waves and storms because global warming is rapidly melting it at a rate of 70,000 square kilometers (27 square miles) each year, he said.

Multiyear sea ice used to cover 90 percent of the Arctic basin, Barber said. It now covers roughly 19 percent. Where it used to be up to 10 meters thick (32 feet), it's now two meters (6 feet) at most. The findings, which are soon to be published in the journal Geophysical Research Letters, come as a shock to experts worldwide. Although northern sea ice hit a record low in 2007, researchers believed it was recovering because of what they were seeing on satellite images.


Posted by Amanda Graham – 28 November 2009; 12:04:17 PM – Permalink  

New book and launch: The Kandik Map, by Linda Johnson

(University of Alaska Press, 15 October 2009/28 November 2009) -- In 1880, a Native American named Paul Kandik and a French explorer, François Mercier, traveled across northeastern Alaska and western Canada to create the earliest known map of the region. Linda Johnson now delves into the fascinating story behind the Kandik Map, examining the reasons why and how these two men from such different backgrounds combined their extensive knowledge of the country to map the Kandik River region. Drawing on historical letters, geographical analysis, and the original map itself held in the University of California’s Bancroft Library, Johnson produces a groundbreaking study on the history of the Kandik Map and reveals its significant implications for Native American scholarship.

Book launch in Whitehorse: 2 December 2009, Yukon Archives Display Room, 3:30 to 5:00 pm. For more information call 867-668-4205. Refreshments. Everyone is very welcome to attend.


Posted by Amanda Graham – 28 November 2009; 11:32:43 AM – Permalink  

Researchers establish common seasonal pattern among bacterial communities in Arctic rivers

(University of Maryland Center for Environmental Science press release via EurekAlert! 24 November 2009) -- Cambridge, Md. - New research on bacterial communities throughout six large Arctic river ecosystems reveals predictable temporal patterns, suggesting that scientists could use these communities as markers for monitoring climate change in the polar regions.

The study, published this week in the Proceedings of the National Academy of Sciences Early Edition, shows that bacterial communities in the six rivers shifted synchronously over time, correlating with seasonal shifts in hydrology and biogeochemistry. The research team documents these patterns through a three-year, circumpolar study of planktonic bacterial communities in the six largest rivers of the pan-arctic watershed: the Ob', Yenisey, Lena, Kolyma, Yukon, and Mackenzie Rivers.

"Our results demonstrate that synchrony, seasonality and annual reassembly in planktonic bacterial communities occur on global scales," said lead author Dr. Byron Crump of the University of Maryland Center for Environmental Science Horn Point Laboratory. "Since bacterial communities in big arctic rivers shift predictably with circumpolar seasonal changes in environmental conditions, they may serve as sensitive indicators of climate change in the Arctic."

"The six river systems studied are comparable in size to the Mississippi River in the United States," said coauthor Rainer Amon of Texas A&M University at Galveston. "One of the things we learned is the bacteria communities in all six of them seem to be very similar. There are many questions still to be answered, such as how these bacteria communities might respond to a continued increase in temperature."


Posted by Amanda Graham – 25 November 2009; 10:47:26 AM – Permalink  

Ancient hunters not to blame for driving mammoths to extinction

(Ian Sample/Guardian, 19 November 2009) -- Woolly mammoths and other large, lumbering beasts faced extinction long before early humans perfected their skills as spearmakers, scientists say. The prehistoric giants began their precipitous decline nearly 2,000 years before our ancestors turned stone fragments into sophisticated spearpoints at the end of the last ice age. The animals, which included mammoths, elephant-sized mastodons and beavers the size of black bears, were probably picked off by more inept hunters who only much later developed specialised weapons when their prize catches became scarce.

"Some people thought humans arrived and decimated the populations of these animals in a few hundred years, but what we've found is not consistent with that rapid 'blitzkrieg' overkill of large animals," said Jacquelyn Gill, a PhD student at the University of Wisconsin, Madison, who led the research team. ... The rise of the Clovis culture was thought to coincide with the demise of the woolly mammoth and other slow-moving giants on the continent, leading many researchers to suspect the animals died at the ends of the hunters' spears.

Gill's team rules this out by putting a more accurate date on the decline and fall of woolly mammoths and more than 30 other large mammals that dominated the landscape as the ice sheets retreated from North America. Among them were giant sloths the size of SUVs. ... Writing the US journal Science, the researchers describe how the amount of mammal dung started to fall around 14,800 years ago, long before advanced spearheads became commonplace. The animals had been almost completely wiped out a thousand years later. "We know there were people who pre-dated the Clovis culture who were butchering mammoths in the area. What we're suggesting is the declines happened before the Clovis toolkit was adopted. These earlier people had tools, but they probably weren't as sophisticated," said Gill.


Posted by Amanda Graham – 25 November 2009; 1:21:54 AM – Permalink  

Acid in Arctic waters eating away at shellfish

(Nunatsiaq News, 20 November 2009) -- Greenhouse gas emissions from vehicles, power stations and industries far to the south are putting shellfish in the Arctic Ocean at risk, an international team reports in the Nov. 20 edition of the journal Science. Acidification may put “some species may be at risk,” say the researchers — this would have a major impact on the entire marine food chain. And acidification is expected to increase as sea ice cover decreases due to global warming, they say.

Ten years of study in the Beaufort Sea showed the seawater is becoming more acidic and fresher, which means there’s less of minerals and carbonate needed for shell formation. The shellfish which may now be at risk include mussels and clams that need minerals in the water to form their shells and skeletons. If emissions of carbon dioxide are not curbed, the researchers conclude “the Arctic ecosystem may be at risk,” because the acidification of the seawater and resulting damage to shellfish could affect other marine life and fisheries.


Posted by Amanda Graham – 20 November 2009; 3:51:50 PM – Permalink  

Icy oil spill easier to clean, scientists say

(Elizabeth Bluemink/Anchorage Daily News, 17 November 2009) -- Scientists funded by Shell and six other oil companies say that cleaning up oil spills in Arctic ice is in many respects easier than cleaning it from open water. The reason, they said Tuesday, is that oil spilled in open water tends to spread out quickly over large areas and contaminate the shoreline. In contrast, recent testing in the Barents Sea above northern Europe has shown that ice can act as a natural blockade that traps the oil and gives responders more time to clean it up. The researchers' preliminary findings conflict with the conventional wisdom about how spills in Arctic ice would be difficult, if not impossible, to clean up.

Environmentalists cite botched spill cleanup experiments that occurred a decade ago in the Beaufort Sea. At the time, the state concluded that Prudhoe Bay oil field operator BP could not adequately clean spills in slushy water. Shell says spill-response techniques have improved greatly since then and is trying to enlist Alaskans' support for offshore exploration in federal waters. The company spent more than $2 billion last year to acquire leases and is seeking state and federal permits to explore for oil next summer in the Beaufort and Chukchi seas, which geologists say may hold vast amounts of oil and natural gas. But several conservation groups and Arctic village governments have sued to block Shell's drilling, saying it could result in pollution or interfere with subsistence whale hunts.


Posted by Amanda Graham – 18 November 2009; 2:05:31 PM – Permalink  

New report: boreal forests contain more carbon than tropical forest per hectare

(Jeremy Hance, mongabay.com, 12 November 2009) -- A new report states that boreal forests store nearly twice as much carbon as tropical forests per hectare: a fact which researchers say should make the conservation of boreal forests as important as tropical in climate change negotiations. The report from the Canadian Boreal Initiative and the Boreal Songbird Initiative, entitled The Carbon the World Forgot, estimates that the boreal forest—which survives in massive swathes across Alaska, Canada, Northern Europe, and Russia—stores 22 percent of all carbon on the earth's land surface. According to the study the boreal contains 703 gigatons of carbon, while the world's tropical forests contain 375 gigatons.

"Past accounting greatly underestimated the amount and depth of carbon stored in and under the boreal forest," says Jeff Wells, one of the report's authors. Researchers explain that while tropical forests store most of their carbon in vegetation, boreal forests store vast amounts of the greenhouse gas deep in permafrost soil and peatlands in addition to its trees. Cold temperatures prevent the complete breakdown of dead biomass in the boreal, so that carbon is accumulated over time, sometimes even millennia. Scientists have found carbon that has been locked away for 8,000 years. ...

Wells says that these findings should not change scientists' or policymakers' view that tropical forests require immediate protection, but only that boreal forests must also be included in negotiations if the world is to successfully to mitigate climate change.

See the report here: http://www.borealbirds.org/carbonreport.shtml or download the full report.


Posted by Amanda Graham – 12 November 2009; 9:44:52 PM – Permalink  

Greenland ice loss accelerating: study

(Alister Doyle/Reuters, 12 November 2009) -- Greenland's ice losses are accelerating and nudging up sea levels, according to a study showing that icebergs breaking away and meltwater runoff are equally to blame for the shrinking ice sheet. The report, using computer models to confirm satellite readings, indicated that ice losses quickened in 2006-08 to the equivalent of 0.75 mm (0.03 inch) of world sea level rise per year from an average 0.46 mm a year for 2000-08.

"Mass loss has accelerated," said Michiel van den Broeke, of Utrecht University in the Netherlands, who led the study, in Friday's edition of the journal Science. "The years 2006-08, with their warm summers, have seen a huge melting," he told Reuters of the study with colleagues in the United States, the Netherlands and Britain. "The underlying causes suggest this trend is likely to continue in the near future," Jonathan Bamber, a co-author at the University of Bristol, said in a statement. The computer models matched satellite data for ice losses—raising confidence in the findings—and showed that losses were due equally to meltwater, caused by rising temperatures, and icebergs breaking off from glaciers.


Posted by Amanda Graham – 12 November 2009; 9:39:32 PM – Permalink  

Ancient penguin DNA raises doubts about accuracy of genetic dating techniques

(Oregon State University press release via EurekAlert! 10 November 2009) -- CORVALLIS, Ore. - Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been routinely underestimating the age of many specimens by 200 to 600 percent.

In other words, a biological specimen determined by traditional DNA testing to be 100,000 years old may actually be 200,000 to 600,000 years old, researchers suggest in a new report in Trends in Genetics, a professional journal. The findings raise doubts about the accuracy of many evolutionary rates based on conventional types of genetic analysis.

"Some earlier work based on small amounts of DNA indicated this same problem, but now we have more conclusive evidence based on the study of almost an entire mitochondrial genome," said Dee Denver, an evolutionary biologist with the Center for Genome Research and Biocomputing at Oregon State University. "The observations in this report appear to be fundamental and should extend to most animal species," he added. "We believe that traditional DNA dating techniques are fundamentally flawed, and that the rates of evolution are in fact much faster than conventional technologies have led us to believe." ... "For the genetic analysis to be accurate, however, you must have the right molecular clock rate," Denver said. "We now think that many genetic changes were happening that conventional DNA analysis did not capture. They were fairly easy to use and apply but also too indirect, and inaccurate as a result."

A precise study of this ancient DNA was compared to the known ages of the bones, and produced results that were far different than conventional analysis would have suggested. Researchers also determined that different types of DNA sequences changed at different rates. Aside from raising doubts about the accuracy of many specimens dated with conventional approaches, the study may give researchers tools to improve their future dating estimates, Denver said.


Posted by Amanda Graham – 11 November 2009; 9:45:30 AM – Permalink  

Researcher's analysis shows buying Alaska no sweet deal for American taxpayers

(Newswise, 6 November 2009) -- Sarah Palin has a new book out, and the former Alaska governor's rise to fame has brought more notoriety to her native state than it's had since the United States dropped $7.2 million in gold to buy it from Russia in 1867. But a new analysis by a University of Iowa economist suggests the investment hasn't been worth it for U.S taxpayers.

"Cash flow from Alaska to the federal government since 1867 has certainly exceeded the initial purchase price, but this fact is not sufficient to demonstrate the purchase was a sound financial investment," said David Barker, an economist and adjunct professor of finance in the Tippie College of Business. "The economic benefits that have been received from Alaska over the years could have been obtained without purchasing the territory. In financial terms, Alaska has clearly been a negative net present value project for the United States." Barker acknowledges that Alaska provides many benefits to the country. It's a rich source of natural resources, especially oil; its vistas, open spaces and wildlife provide unmatched natural beauty; and, for many Republicans like Barker, there's Palin herself. But Barker argues that the federal government spent so much money to acquire Alaska (the $7.2 million in gold had the value of about $10 million in greenback currency at the time), then govern the area and build the infrastructure needed to access its resources that whatever financial benefits the state has provided have been far offset by the costs.

By Barker's calculation, the state has cost the federal government $13.4 million in 1867 dollars, which translates to a $16.5 billion loss in today's dollars, adjusting for the size of the economy. ... As for revenues, Barker said the federal government has collected many forms of them from Alaskans over the years, including income and excise taxes, a seal fur tax early in the territory's history, land leasing and sales, and, most significantly, taxes on oil. But he said that revenue can best be described as "occasional spikes followed by long periods of net federal subsidy" and have never offset the costs to the American taxpayer of purchasing, financing and paying to develop Alaska. Even today, no state collects more federal aid than Alaska, Barker said. Barker also acknowledges that Alaska has been helpful strategically to the United States. For instance, its North Slope reserves provide an important domestic source of oil for the country.

But Barker points out the belief among many historians that if the United States had not purchased Alaska, Great Britain would have acquired it and made it a part of Canada. Given the historically close and friendly relationship between the United States and Canada, Barker said Americans still would have had access to Alaska's resources, just as Americans today have largely open access to Canada's resources, including its oil. But that access would have come at a much lower cost to Americans, Barker notes, because the costs of developing the region's economy with roads, rail, port facilities and other infrastructure would have been paid by Canadian taxpayers, not American. A copy of Barker's study is available online at http://news-releases.uiowa.edu/2009/november/David%20Barker-Alaska.pdf


Posted by Amanda Graham – 6 November 2009; 4:16:29 PM – Permalink  

Tackling new Arctic challenges from space

(European Space Agency, 5 November 2009) -- International scientists, researchers and decision makers met at the 'Space and the Arctic workshop' to identify the needs and challenges of working and living in the rapidly changing Arctic and to explore how space-based services can help to meet those needs. The workshop, held from 20 to 21 October in Stockholm, Sweden, was organised by the Swedish National Space Board and the Swedish Meteorological and Hydrological Institute together with ESA, EUMETSAT and the EC. ... One of the highlights of the workshop was the 'Arctic Marine Transport and Space' presentation given by Dr Lawson Brigham of the University of Alaska Fairbanks that outlined the Arctic Marine Shipping Assessment (AMSA) report for 2009. ...

"New space assets are crucial for improving marine communications in many regions of the Arctic Ocean in order to improve search and rescue and environmental response activities," Brigham said. "One key AMSA recommendation is the need for a comprehensive Arctic marine traffic awareness system; only space assets in the long-term can provide the coverage necessary to achieve effective monitoring and tracking of Arctic ships." "Improved space sensors measuring sea-ice thickness, mapping snow cover and tracking icebergs will be increasingly important to Arctic ship safety and route optimisation," he continued. "Continued satellite monitoring is also central to recording the retreat of sea ice and other changes to the cryosphere in a warming Arctic." In order to build the infrastructure needed in the Arctic to meet these challenges, workshop participants investigated ways space infrastructure could facilitate communication, environmental monitoring, early warning systems and navigation and vessel tracking in the area.

The workshop was held under the auspices of the Swedish Presidency of the Council of the EU as part of a commitment to face the challenges of climate change and increased human activity. It focused on these main themes: climate change and environment; transport safety and security; and sustainable exploitation.


Posted by Amanda Graham – 6 November 2009; 3:40:43 PM – Permalink  

New translation explores life of Russian scientist and Gulag survivor

(Arctic Institute of North America, 2 November 2009) -- One of the most prominent Soviet Arctic scientists of the 1920s and 1930s, Mikhail Mikhailovich Ermolaev was a geologist, physicist, and oceanographer. After working in the Arctic for some 13 years, he was arrested by the Russian police force (NKVD), convicted on a trumped-up charge of "sabotage," and sent to the Gulag for ten years.

The original Russian biography of this fascinating man was written by Ermolaev's son, Sleksei Mikhailovich Ermolaev, and V.M. Diber. Translated from the original Russian and edited by William Barr, Arctic Scientist, Gulag Survivor: The Biography of Mikhail Mikhailovich Ermolaev, 1905-1991 (University of Calgary Press, 2009, $44.95) is a fascinating personal account typical of the experiences of so many Soviet citizens who were unjustly banished to the infamous Gulag. Because Ermolaev was part of a specialist team, the conditions he endured were better than most, with reasonably comfortable quarters and relatively adequate food. However, his story still clearly illustrates the brutality and inhumanity of the system.

After barely surviving a year of correctional hard labour in a lumber camp, Ermolaev was appointed to a sharashka, or professional team, which was charged with extending the railroad to the coal mines of Vorkuta in the farthest reaches of northeastern European Russia. Still later, he and his family were exiled to Syktyvkar and Arkhangel'sk. Remarkably, Ermolaev was eventually able to resume his academic career, ultimately establishing a new Department of the Geography of the Oceans at Kaliningrad State University.

Aleksei's recollections of his father's arrest and of the family's experiences while his father was in the Gulag, along with an excellent selection of family photographs, infuse Arctic Scientist, Gulag Survivor with a sense of immediacy and personal connection. Thanks to the expertise of William Barr, Ermolaev's story is now available in English for the first time.


Posted by Amanda Graham – 2 November 2009; 10:04:00 PM – Permalink  

Russian tundra getting greener

(Barents Observer, 22 October 2009) -- New research has uncovered a significant clue in solving one of the lingering mysteries in climate change: what is causing the significant increase in Arctic tundra productivity detected by satellites since the early 1980s?

Groundbreaking research, led by Bruce Forbes, professor at the Arctic Centre, University of Lapland in Rovaniemi, has been able to pinpoint what has long been suspected but never quantified (the release). By studying the annual growth rings of a common and widespread willow species, an international team of researchers has determined that deciduous, or leafy, tundra shrubs closely track Russian Arctic warming and ‘greening’. A regional increase in shrub cover has important implications for future climate due to feedbacks between the ground surface and earth’s atmosphere. The researchers have been studying the areas on the tundra in the Nenets Autonomous Okrug in the northern part of the Barents Region.

"In the earliest stages of this research I had information from Nenets reindeer herders, who are indigenous to the area, that shrubs seemed to have increased in height during their lifetime," explains lead author Bruce Forbes, who did his field research in Russia’s Nenets Autonomous Okrug, about 20 km inland from the coast of the Barents Sea. According to meteorological observation, the temperature in the Arctic is rising two times faster than the world’s average temperature, reports Bellona web with reference to Murmansk Hydro-Meteorological Centre. 2007 was the warmest year in the region since 1961. According to Yelena Siekkinen of the Murmansk Hydro-Meteorological Centre, observations of the temperature in the region show a 0.7 degree Celsius rise every decade since 1976. In other words, the temperature in Russia’s Arctic region has risen more than 2 degrees Celsius over the last 30 years.


Posted by Amanda Graham – 26 October 2009; 10:18:12 PM – Permalink  

Current Arctic heat wave among rarest in 200,000 years, study says

(Martin Mittelstaedt/Globe and Mail, 19 October 2009) -- The Canadian Arctic is experiencing a heat wave that has seldom been matched in the past 200,000 years, says a new scientific paper based on the study of sediments found at the bottom of a remote lake on Baffin Island.

Scientists looking at the remains of microscopic plants and insects preserved in the lake's crusty bottom say a comparison of flora and fauna found in the remote past and in recent decades suggest temperatures are now so elevated they've rarely occurred. Over the 200,000 years in question, the sediments revealed a natural ebbing and rising of various species that either favoured warmer or colder climate conditions. But recently there have been unprecedented increases of some algae types dependent on warmer conditions that were almost never found during the pre-industrial era.

“Our findings show that the last several decades have been the most ecologically unique in 200,000 years,” said Neil Michelutti, a research scientist at Queen's University in Kingston, Ont., and one of the members of the team that conducted the study, which is appearing this week in the online edition of the Proceedings of the National Academy of Sciences.


Posted by Amanda Graham – 20 October 2009; 9:52:21 AM – Permalink  

Arctic to be ice-free in summer in 20 years: scientist

(Peter Griffiths/Reuters, 15 October 2009) -- LONDON - Global warming will leave the Arctic Ocean ice-free during the summer within 20 years, raising sea levels and harming wildlife such as seals and polar bears, a leading British polar scientist said on Thursday. Peter Wadhams, professor of ocean physics at the University of Cambridge, said much of the melting will take place within a decade, although the winter ice will stay for hundreds of years.

The changes will mean the top of the Earth will appear blue rather than white when photographed from space and ships will have a new sea route north of Russia.

Scientists say evidence of melting Arctic ice is one of the clearest signs of global warming and it should send a warning to world leaders meeting in Copenhagen in December for U.N. talks on a new climate treaty.

"The data supports the new consensus view—based on seasonal variation of ice extent and thickness, changes in temperatures, winds and especially ice composition—that the Arctic will be ice-free in summer within about 20 years," Wadhams said in a statement. "Much of the decrease will be happening within 10 years." [See also,  Schueneman/Environmental News Network, "Scientists suggest new Arctic study may oversate sea ice melting," 17 October 2009.]


Posted by Amanda Graham – 15 October 2009; 10:36:41 AM – Permalink  

Arctic land and seas account for up to 25 percent of world's carbon sink

(Ecological Society of America press release via EurekAlerts, 14 October 2009) -- In a new study in the journal Ecological Monographs, ecologists estimate that Arctic lands and oceans are responsible for up to 25 percent of the global net sink of atmospheric carbon dioxide. Under current predictions of global warming, this Arctic sink could be diminished or reversed, potentially accelerating predicted rates of climate change.

In their review paper, David McGuire of the U.S. Geological Survey and the University of Alaska at Fairbanks and his colleagues show that the Arctic has been a carbon sink since the end of the last Ice Age, which over time has accounted for between zero and 25 percent, or up to about 800 million metric tons, of the global carbon sink. On average, says McGuire, the Arctic accounts for 10-15 percent of the Earth's carbon sink. But the rapid rate of climate change in the Arctic—about twice that of lower latitudes—could eliminate the sink and possibly make the Arctic a source of carbon dioxide.

Carbon generally enters the oceans and land masses of the Arctic from the atmosphere and largely accumulates in permafrost, the frozen layer of soil underneath the land's surface. Unlike active soils, permafrost does not decompose its carbon; thus, the carbon becomes trapped in the frozen soil. Cold conditions at the surface have also slowed the rate of organic matter decomposition, McGuire says, allowing Arctic carbon accumulation to exceed its release. But recent warming trends could change this balance. Warmer temperatures can accelerate the rate of surface decomposition, releasing more carbon into the atmosphere.

More concerning, says McGuire, is that the permafrost has begun to thaw, exposing previously frozen soil to decomposition and erosion. These changes could reverse the historical role of the Arctic as a sink for carbon. "In the short term, warming temperatures could expose more Arctic carbon to decomposition," says McGuire. "And with permafrost melting, there will be more available carbon to decompose."


Posted by Amanda Graham – 15 October 2009; 10:17:45 AM – Permalink  

New emphases in Arctic climate change research

(ScientistLive, 8 October 2009) -- Much of circumpolar Arctic research focuses on the physical, direct changes resulting from climate warming such as sea ice retreat and temperature increases. “What’s understudied is the living component of the Arctic and that includes humans,” said Syndonia “Donie” Bret-Harte, associate professor of biology at the University of Alaska Fairbanks and co-author of a paper to be published September 11, 2009 in the journal Science.

The paper reviews current knowledge on the ecological consequences of climate change on the circumpolar Arctic and issues a call for action in several areas of global climate change research. ... The international team of scientists who collaborated on this paper reviewed dozens of research documents on the effects of circumpolar Arctic warming. They note that numerous direct effects including lengthening of growing season following a rapid spring melt, earlier plant flowering and appearance of insects following a warmer spring, deaths of newborn seal pups following melting of their under-snow birthing chambers have other, often more subtle, indirect effects on plants, animals and humans that warrants increased attention.

Understanding how changes in plant and animal populations affect each other and how they affect the physical or nonliving components of the Arctic is critical to understanding how climate warming will change the Arctic. ... The authors call for immediate attention to the conservation of Arctic ecosystems; understanding the ecology of Arctic winters; understanding extreme events such as wildfires and extended droughts; and the need for more baseline studies to improve predictions.


Posted by Amanda Graham – 8 October 2009; 4:06:49 PM – Permalink  

Earth's glaciers melting at an accelerated rate

(Physicsworld.com, 24 September 2009) -- Glaciers along the margins of Antarctica and Greenland are flowing into the ocean at an ever-increasing rate due to rising sea temperatures, warn researchers in the UK. The "dynamic thinning" of these high-latitude ice sheets has been tracked over a five-year period using lasers on board a NASA satellite and detailed in a new series of topological maps. The unprecedented resolution of the data could help physicists to develop more accurate models of the poorly understood processes involved in glacial melting.

Glaciers are like "rivers of ice" that drain water from the mountains to lower levels. Where the ice meets the sea it either melts, breaks away into the ocean as icebergs, or feeds into the ice shelf—a floating extension of the land. Under stable environmental conditions there exists a balance in which ice lost to the sea as melt is continually replaced by the falling of snow inland. However, a sudden rise in sea temperatures can cause this balance to be disturbed—the result being that coastal ice-melt is not sufficiently replaced by inland precipitation.

Scientists estimate that melting land ice is contributing 1.8 mm of the current 3.2 mm annual sea rise. In the latest report of the Intergovernmental Panel on Climate Change (IPCC) there is a worst-case scenario in which a 4 °C rise by 2090–2099 will result in an average sea-level rise of 0.26–0.59 m within the same period. The forecasted rise comes from a combination of melting ice sheets and the thermal expansion of sea waters.


Posted by Amanda Graham – 24 September 2009; 11:52:19 AM – Permalink  

Northern brown bears discovered feeding on whitefish runs

(Arctic Institute of North America, 22 September 2009) -- The discovery of brown (grizzly) bears feeding on migrating broad whitefish in a stream in Mackenzie Delta region of the Northwest Territories has researchers advising increased care in petroleum extraction and infrastructure development within the area. In a paper published in the September issue of the journal Arctic, Oliver Barker and Andrew Derocher from the University of Alberta report seeing at least one brown bear engaged in the unusual activity of caching whitefish at Pete's Creek, a small Mackenzie River tributary located between Inuvik and Tuktoyaktuk. While it is well known that brown bears feed on salmon, trout and charr, this is the first scientific reporting of brown bears feeding on whitefish and supports what is recorded from local traditional knowledge. Each spring since 2003, several bears were outfitted with satellite radio-collars. In October 2007, while conducting a helicopter survey of the bears, the researchers noticed two patches of disturbed ground near Pete's Creek. What they found when they landed surprised them: two caches with whole and partially eaten whitefish.

"My first impression was excitement. My second was apprehension," says Barker, "I don't like being in willow thickets when there are bears nearby." Realizing their shotgun was in the helicopter, Barker beat a hasty retreat. Once in the air, they did indeed observe a young female nearby. "She was quite fat and shiny. Very roly-poly,'" recalls Barker. Brown bears in the Mackenzie Delta face several challenges. Not only are food sources scarce, the bears are often active for just five months of the year. This creates extreme pressure for them to find adequate nutrition.

"These bears are real opportunists. They'll take advantage of different food sources," says Barker. This means some will turn to whitefish which are easily available in large numbers when they migrate in the fall. And although bears are omnivores and can exist on mostly vegetarian diets, fish are a better food source because they are rich in protein and fat. Barker says the fall run of whitefish could be playing a significant role in the diets of some Mackenzie Delta brown bears. He would like to see more research conducted on the bears and their feeding habits, in order to mitigate the impacts of development activities. "Pete's Creek may be an important but spatially concentrated food source, but we can't put it into context until we know more" says Barker. "It could take a small amount of disturbance in an area like this to disrupt these bears. There is still a lot we don't know about Mackenzie Delta bears, and any development should be mindful of such resources."


Posted by Amanda Graham – 22 September 2009; 10:03:50 PM – Permalink  

Polar bears on involuntary diets

(Norden News, 8 September 2009) -- Climate change is causing weight loss among polar bears as the ice starts to thaw earlier and earlier each spring, according to a new report by the Nordic Council of Ministers.  The earlier thaw restricts the number of seals the bears are able to hunt, and in certain parts of the Arctic the average female now weighs only 225 kgs, i.e. 25% less than two decades ago. If the trend continues there is a risk of the polar bear disappearing completely from parts of the Arctic.

The purpose of the new report was to identify indicators that will help quantify the impact of climate change and follow developments in Nordic eco-systems. The 14 indicators also describe the impact of global warming on, for example, the growing- and pollen seasons as well as fish and plankton stocks. Pollen seasons are starting earlier and earlier, making life more difficult for allergy sufferers. In parts of Denmark, Norway and Iceland the birch pollen season now starts a month earlier than it did in the 1980s, for example.

The report Signs of Climate Change in Nordic Nature was written by a working party under the auspices of the Nordic Council of Ministers' environment sector.  Read the report. More on Nordic co-operation on the environment


Posted by Amanda Graham – 22 September 2009; 11:05:22 AM – Permalink  

Opting out of migration: as climate warms, Arctic-nesting geese elect to winter in Alaska instead of Mexico

(U.S. Geological Survey press release, 9 September 2009) -- The winter distribution of Pacific brant, a small, dark sea goose, has shifted northward from low-temperate areas such as Mexico to sub-Arctic areas as Alaska’s climate has warmed over the last four decades, according to a just-released article in Arctic.

Until recently, nearly the entire (90 percent) population of Pacific brant wintered in Mexico, but now as many as to 30 percent are opting to spend their winters in Alaska instead, according to the U.S. Geological Survey-led study. Although records are sparse, fewer than 3,000 brant were detected wintering in Alaska before 1977, a number that has jumped to as many as 40,000 birds now. Pacific brant breed primarily in Alaska and winter along the Pacific coast of North America from Alaska to Mexico. The species is "of federal management concern" because its numbers have been declining steadily across its entire range since the early 1960s.

"This increase in wintering numbers of brant in Alaska coincides with a general warming of temperatures in the North Pacific and Bering Sea," said David Ward, the lead author of the study and a USGS researcher at the Alaska Science Center. "This suggests that environmental conditions have changed for one of the northernmost-wintering populations of geese." ... Brant, said Ward, are "short-stopping" on their southward migration and remaining north of their traditional wintering grounds farther south.  Ward and his co-authors suspect that Pacific brant numbers will continue to increase in Alaska during winter, given climate predictions for ever-warming temperatures and less ice at higher latitudes.  But, he cautions, the picture may not be all that balmy for brant wintering in Alaska.


Posted by Amanda Graham – 20 September 2009; 12:17:17 PM – Permalink  

How will Greenland’s glacier melt change sea levels?

(redOrbit, 11 September 2009) -- Scientists are trying to determine what occurred in Greenland’s history to cause its glaciers to rapidly melt, and what implications it might have for the earth’s future in light of looming global warming. In 2005, scientists noticed that Greenland’s Helheim Glacier had nearly doubled in speed as it moved through a river at a pace of 100 feet per day. The rapid movement caught researchers by surprise and sparked concerns that it could be a sign of a massive melting of the Greenland’s ice sheet to come.

"It does seem that the very rapid speeds were only sustained for a short period of time, although none of these glaciers have returned to the 'normal' flow speeds yet," Gordon Hamilton, a glaciologist from the University of Maine, told the Associated Press.

A melting of the massive two-mile-thick ice sheet could result in a global sea level increase of 20 feet. Now scientists are trying to recover information that could provide clues as to why Greenland’s glaciers sped up five years ago as the world confronts the dangers of global warming.

"This is like medical science in the 15th century," David Holland, director of the Center for Atmosphere Ocean Science at New York University, told the AP.


Posted by Amanda Graham – 12 September 2009; 2:02:36 PM – Permalink  

Scientists scale new heights underwater

(Paul Watson/Toronto Star, 11 September 2009) -- VANCOUVER - Breaking through heavy polar ice, a joint mission of Canadian and American scientists has explored unseen areas of Canada's Arctic sea floor, including what looks like an undersea mountain and volcano buried in thick sediment.

A joint mission by mapping teams aboard the Canadian Coast Guard's CCGS Louis S. St-Laurent and the U. S. Coast Guard's USCGC Healy in the high Arctic gathered some 40 per cent more data than expected, scientists said by satellite phone from the ships today. Part of Canada's Arctic sovereignty claim depends on finding evidence far below the polar ice in sediments that have piled up on the seabed over eons. Finding thick sediments in the previously unmapped region where the seamount was discovered may help Ottawa make its case that Canada's continental shelf extends high into the Arctic.

"It's too early to say where the outer limits will be," Jacob Verhoef, the Halifax-based official who heads Canada's Arctic seabed mapping operations, told Canadian and U. S. reporters. "I think our aim at the moment is to collect the best scientific information, to do the best we can to define those outer limits. And the next step, if there are any kind of potential conflicts or overlaps, is to resolve that in a peaceful way.

"Using sound waves from powerful bubbles fired from air guns, and high-frequency sound pulses, scientists aboard the two icebreakers were able to get a two-dimensional view of a part of the Earth humans have never seen before.


Posted by Amanda Graham – 12 September 2009; 11:25:33 AM – Permalink  

Arctic oil a bonus for nest predators

(redOrbit, 8 September 2009) -- A new study by the Wildlife Conservation Society, U.S. Fish and Wildlife Service, and other groups reveals how oil development in the Artic is impacting some bird populations by providing "subsidized housing" to predators, which nest and den around drilling infrastructure and supplement their diets with garbage – and nesting birds. Oil development has attracted populations of opportunistic predators including Arctic fox, ravens, and gulls, which feed on nesting birds. The predators use oil infrastructure, which ranges from drilling platforms to road culverts, to build their nests or dens. In this study researchers found one bird species, the Lapland longspur, lost significantly more nests in areas closer to oil development than farther away. Nests beyond 5 kilometers (3.11 miles) from oil development remained unaffected by predators.

Other birds, including red and red-necked phalaropes, may also be feeling impacts from predators, though data was less strong than with longspurs. At the same time, other species tested did not show an effect. Authors believe this may be due to high natural variation in nesting success across years and between sites. The study appears in the September issue of the journal Ecological Applications.


Posted by Amanda Graham – 8 September 2009; 7:00:08 PM – Permalink  

Gamburstev and the Alps underneath the Antarctic

(ScientificBlogging.com, 8 September 2009) -- An international team of scientists has not only verified the existence of a mountain range that is suspected to have caused the massive East Antarctic Ice Sheet to form, but also has created a detailed picture of the rugged landscape buried under more than four kilometers (2.5 miles) of ice.

"Working cooperatively in some of the harshest conditions imaginable, all the while working in temperatures that averaged -30 degrees Celsius, our seven-nation team has produced detailed images of last unexplored mountain range on Earth," said Michael Studinger, of Columbia University's Lamont-Doherty Earth Observatory, the co-leader of the U.S. portion of the Antarctica's Gamburstev Province (AGAP) project. "As our two survey aircraft flew over the flat white ice sheet, the instrumentation revealed a remarkably rugged terrain with deeply etched valleys and very steep mountain peaks."

The initial AGAP findings—which are based on both the aerogeophysical surveys and on data from a network of seismic sensors deployed as part of the project—while extremely exciting, also raise additional questions about the role of the Gamburtsevs in birthing the East Antarctic Ice Sheet, which extends over more than 10 million square kilometers atop the bedrock of Antarctica, said geophysicist Fausto Ferraccioli, of the British Antarctic Survey (BAS), who led the U.K. science team.


Posted by Amanda Graham – 8 September 2009; 6:54:11 PM – Permalink  

Satellite altimetry quantifies the alarming thinning of Arctic sea ice

(Mark Wilson/Physics Today, American Institute of Physics, September 2009) -- The Arctic Ocean's floating sea-ice cover waxes and wanes with the seasons. The icecap grows in the fall when the hours of sunlight shorten and intense cold sets in. When long summer days return, ice floes melt or are driven by wind and ocean currents into the North Atlantic Ocean.

A quarter century ago, the coverage ranged from about 7 million to 16 million km2 between late summer and the following March. Since 1978, when satellites began routinely monitoring the Arctic, the extent covered by perennial ice—that which survives the summer melt—has declined by close to 10% per decade, at least until 2007. In September of that year, the summer ice extent plummeted to a record low 4.2 million km2, down 23% from a previous record low in 2005. The perennial ice lost in those two years alone covered an area almost twice the size of Texas. ...

For basinwide estimates of ice thickness, researchers had to wait until 2003, when Seymour Laxon and colleagues from University College London published the first radar-altimetry data taken from the European Space Agency’s ERS-1 and ERS-2 satellites.


Posted by Amanda Graham – 4 September 2009; 4:21:17 PM – Permalink  

Man's link to melting Arctic revealed in historic study

(Bob Weber/The Canadian Press, 4 September 2009) --  A groundbreaking study that traces Arctic temperatures further back than ever before has shown the region is now warmer than at any time in the last 2,000 years. The study, published yesterday in the journal Science, also provides real-world evidence to back mathematical climate models that suggest greenhouse gases are behind global warming.

"There are no other forcing factors at work other than the greenhouse gas composition of the atmosphere that could explain the dramatic warming that took place," said Darrell Kaufman, the paper's lead author, from Northern Arizona University. Kaufman and nearly three dozen scientists used data from tree rings, lake sediments and glacial ice deposits from 23 sites around the circumpolar world to track average summer temperatures for every decade of the last two millennia—1,600 years longer than had ever been done before. All three methods are accepted gauges of weather. The warmer the summer, the thicker a tree ring or layer of organic sediment.

The measurements showed that from Year 1 to about 1900, summer Arctic temperatures were slowly decreasing by about 0.2C every 1,000 years. That chimes with studies that have calculated the result of tiny decreases in the amount of solar energy the North gets as a result of wobbles in the Earth's orbit. But things began to change at the 20th century's outset. Data from all three sources showed a dramatic upward jog that, in a graph, looks like the blade of a hockey stick. The research suggests four of the Arctic's five warmest decades occurred after 1950. Warmest of all was 1999-2008, with average temperatures about 1.4C higher than they would have been if the cooling trend had continued.

The study says the constancy of other major variables about that time—no large volcanic eruptions, for example—suggests there could only be one culprit for the warming Arctic: carbon dioxide emissions that began increasing rapidly during the Industrial Revolution.

See also USAToday, "Study: Arctic temperatures highest in 2,000 years," 3 September 2009.


Posted by Amanda Graham – 4 September 2009; 10:15:10 AM – Permalink