Students on Ice Blog

Images from 2001, top, and 2007 from Philip’s Universal Atlas of the World indicated a big decline in Arctic ice, used as proof of climate change

Exaggerated claims undermine drive to cut emissions, scientists warn

by Mark Henderson, Science Editor

The Times (October 30, 2009) — Exaggerated and inaccurate claims about the threat from global warming risk undermining efforts to cut greenhouse gas emissions and contain climate change, senior scientists have told The Times.

Environmental lobbyists, politicians, researchers and journalists who distort climate science to support an agenda erode public understanding and play into the hands of sceptics, according to experts including a former government chief scientist.

Excessive statements about the decline of Arctic sea ice, severe weather events and the probability of extreme warming in the next century detract from the credibility of robust findings about climate change, they said.

Such claims can easily be rebutted by critics of global warming science to cast doubt on the whole field. They also confuse the public about what has been established as fact, and what is conjecture.

The experts all believe that global warming is a real phenomenon with serious consequences, and that action to curb emissions is urgently needed.

They fear, however, that the contribution of natural climate variations towards events such as storms, melting ice and heatwaves is too often overlooked, and that possible scenarios about future warming are misleadingly presented as fact.

“I worry a lot that NGOs [non=governmental organisations] are very much in the habit of doing exactly that,” said Professor Sir David King, director of the Smith School for Enterprise and the Environment at the University of Oxford, and a former government chief scientific adviser.

“When people overstate happenings that aren’t necessarily climate change-related, or set up as almost certainties things that are difficult to establish scientifically, it distracts from the science we do understand. The danger is they can be accused of scaremongering. Also, we can all become described as kind of left-wing greens.”

Vicky Pope, head of climate change advice at the Met Office, said: “It isn’t helpful to anybody to exaggerate the situation. It’s scary enough as it is.”

She was particularly critical of claims made by scientists and environmental groups two years ago, when observations showed that Arctic sea ice had declined to the lowest extent on record, 39 per cent below the average between 1979 and 2001. This led Mark Serreze, of the US National Snow and Ice Data Centre, to say that Arctic ice was “in a downward spiral and may have passed the point of no return”.

Dr Pope said that while climate change was a factor, normal variations also played a part, and it was always likely that ice would recover a little in subsequent years, as had happened. It was the long-term downward trend that mattered, rather than the figures for any one year, she added.

“The problem with saying that we’ve reached a tipping point is that when the extent starts to increase again — as it has — the sceptics will come along and say, ‘Well, it’s stopped’,” she said. “This is why it’s important we’re as objective as we can be, and use all the available evidence to make clear what’s actually happening, because neither of those claims is right.”

Myles Allen, head of the Climate Dynamics Group at the University of Oxford, said: “Some claims that were made about the ice anomaly were misleading. A lot of people said this is the beginning of the end of Arctic ice, and of course it recovered the following year and everybody looked a bit silly.” Dr Allen said that predictions of how the world was likely to warm also needed to be framed carefully. While there was little doubt that the Earth would get hotter, there were still many uncertainties about the precise extent and regional impact.

“I think we need to be very careful about purporting to be able to supply very detailed and apparently accurate information about how the climate will be in 50 or 100 years’ time, when what we’re really giving is a possible future climate,” he added.

“We’re not in a position to say how likely it is and what the chances are of it being different. There’s an understandable tendency to want to make climate change real for people and tell them what’s going to happen in their postcode, and that’s very dangerous because it gets beyond the level on which current models can operate.”

Chris Huntingford, of the Centre for Ecology and Hydrology, said: “I think the research scientists in general are extremely cautious about making projections for the future, but that caution is vital. We don’t dispute that warming is happening, but it’s important that the NGOs and other people interested in the issue don’t always pick the high scenario and present it as fact.”

Temperature trends of the past two decades have also been widely mis-interpreted to support particular points of view, the scientists said. Rapid warming in the 1990s, culminating in the hottest year on record in 1998, was erroneously used to suggest that climate change was accelerating. Since then, temperatures have stabilised, prompting sceptics to claim that global warming has stopped.

“In 1998, people thought the world was going to end, temperatures were going up so much,” Dr Pope said. “People pick up whatever makes their argument, but this works both ways. It’s the long-term trend that counts, which is continuing and inexorable.”

For more information, visit http://www.timesonline.co.uk/tol/news/science/earth-environment/article6896152.ece

How ’superswarms’ of krill gather

by Matt Walker, Editor, Earth News

BBC Earth News (October 9, 2009) — When krill come together, they form some of the largest gatherings of life on the planet.

An extraordinary gathering

Now scientists have discovered just how these small marine crustaceans do it.

Huge ’superswarms’ containing trillions of krill are formed by juveniles not adults, and these swarms are even denser than experts supposed.

That suggests that all krill in the Southern Ocean are more vulnerable to overfishing than previously thought, the scientists warn.

Krill are small shrimp-like crustaceans that gather in huge numbers.

Previous research has found that some gatherings of Antarctic krill (Euphausia superba) can stretch for tens of kilometres.

But while huge swarms are known to exist, scientists did not really understand why some swarms are bigger than others, and what drives krill to gather in this way.

So researchers working for the British Antarctic Survey (BAS) decided to investigate the phenomenon.

Led by Dr Geraint Tarling, a BAS researcher based in Cambridge, UK, the research team studied the composition and structure of 4525 separate krill swarms in the Scotia Sea, a vast expanse of water in the Southern Ocean.

The team used echo-sounding equipment, which works much like underwater radar, to find the krill across an area of water equivalent to the eastern half of the Atlantic Ocean.

What they found surprised them.

Krill tend to gather into two distinct types of swarm.

Some krill gather into smaller swarms, no longer than 50m long and up to 4m deep.

These swarms are not very tightly packed, with just ten individual krill per cubic metre, on average.

However, other much bigger swarms also occur.

Dubbed “superswarms”, these are an order of magnitude larger in area, often stretching over one kilometre in length, and averaging almost 30m deep.

What is more, these superswarms are much more densely packed, containing up to ten times greater density of animals.

“I was coming at it thinking there might be small swarms tightly packed, and then large swarms that were a bit more diffuse,” says Dr Tarling.

“But what we actually found was the opposite. There were small swarms that were quite diffuse and large swarms that were tightly packed.”

That means that the majority of krill living in the Antarctic Ocean at any one time will exist within a few, huge superswarms.

“We talking trillions of krill in one aggregation,” explains Dr Tarling.

“Ten or 12 swarms could explain 60 or 70% of the biomass in an area the size of the eastern Atlantic.”

“It was astonishing how much biomass could be concentrated into such a small area.”

A lone shrimp

Youthful gathering

The scientists then searched for reasons why such superswarms form.

Certain factors made superswarms more likely.

“The factors we identified included whether there was more likely to be a lot of food around or not, and when there wasn’t that much food around, they tended to form larger swarms,” says Dr Tarling.

The small, diffuse swarms are usually formed by mature, adult krill, the researchers discovered.

However, the huge superswarms are formed by juvenile krill.

“Where the animals were less mature, they were more likely to form the larger swarms,” says Dr Tarling.

“Why they do that I don’t know.”

A superswarm of krill located by echosounder (swarm shown in red)

Nightime mystery

One possible explanation could be that swarming together offers individual krill protection against marine predators such as whales or seals.

“All types of swarms are probably to a greater or lesser extent an antipredator response. There is safety in numbers, the predator confusion affect,” Dr Tarling says.

But swarming comes at a cost, as each individual shrimp has to compete with millions of others for food.

Adult krill are quite negatively buoyant, and have to keep swimming to stay afloat. That takes a lot of energy, which must be supplied by food, so adult krill likely want to avoid competing with millions of others for their next meal.

But juvenile krill are more buoyant, and need to eat less. So they can afford to gather into huge superswarms for protection.

Another reason could be that researchers have previously shown it is more energetically efficient to be in swarm than be isolated.

“For a juvenile that wants to grow very quickly, saving energy could be a bonus for them,” says Dr Tarling.

One mystery to emerge from the research, which is published in the journal Deep Sea Research I, is that superswarms are more likely to gather at night.

“That is more puzzling for us to explain,” says Dr Tarling.

“Up until this point, most polar biologists believed that the swarms dispersed [at night], because that’s the time they feed.”

“When daylight comes they get back into the swarm again for the antipredator benefit. But we found the opposite to that.”

A handful

Vulnerable to overfishing

The discovery that most krill in the Southern Ocean can be found gathered into just a few superswarms has significant implications for how the animals are fished, Dr Tarling warns.

Fishing fleets can efficiently locate and scoop up whole swarms of krill.

But by fishing out just a few huge superswarms, they may be removing the majority of krill living in the entire ocean.

“Focusing on large swarms can have a much larger effect on the environment than you would predict.”

For more information, visit http://news.bbc.co.uk/earth/hi/earth_news/newsid_8299000/8299690.stm

WHAT IS PLANETCALL?

PlanetCall is an invitation to young people to become co-architects of their future. PlanetCall is about sustainable solutions, and our generation’s willingness to embrace a low-carbon future. Our world is made smaller by the Internet, giving us the power to connect with so many more people. This is exactly what is needed to create innovation and sustainable solutions.

On PlanetCall, you demonstrate your willingness to take part in building this sustainable future by doing three things: Signing the Declaration; Posting a Call; Forwarding on, asking all those you know to do the same.

WHY PARTICIPATE?

PlanetCall is endorsed by the U.N. Secretary-General Ban Ki-moon and the Danish Government, the host of COP15, the United Nations Climate Change Conference to be held in Copenhagen in December 2009. PlanetCall is a global and future-focused resource going beyond describing the problems by demonstrating our willingness to develop sustainable societies. The decision-makers want to know what we demand. Participate. Sign. Make a Call. Your voice will be heard.

WHO ARE WE?

PlanetCall was initiated by Monday Morning, Scandinavia’s leading independent think tank, and the Copenhagen Climate Council, an initiative working for an effective new global treaty in Copenhagen in December 2009. Five youth organizations drive PlanetCall (see Partner page). These organizations form the Executive Committee.

For more information, visit http://www.planetcall.org/

By signing the PlanetCall Declaration you will increase our chances of uniting 1 million global youth on climate change before the U.N. Climate Change Conference in Copenhagen in December.

Tim Flannery
Chair, Copenhagen Climate Council

SOI Alumnus Maéva Gauthier (Antarctic University ‘09) has joined the 2009 CCGS Amundsen expedition – Exploring and documenting marine benthic ecosystems in the Arctic (www.amundsen.ulaval.ca and www.amundsen.quebec-ocean.ulaval.ca).

Location of Expedition:
Maéva and the other researchers began their expedition from Paulatuk (North West Territories) and will finish in Quebec City (Quebec), crossing the North West Passage, Lancaster Sound, along Baffin Island and the Labrador fjords. A SPOT (Satellite transmission of locations through internet) will be available for people to follow the expedition in real time. Maps of the expedition (Leg 4) are available below.

Expedition Itinerary:

Dates of Expedition:
The research cruise will occur from October 8 to November 18, 2009. This is Maéva’s first trip to the Arctic. She assisted with some preliminary explorations last year to test a remotely operated vehicle.

Expedition Participants:
This is an extensive and multidisciplinary national research survey. Maéva will work closely with the Université du Québec à Rimouski.

Expedition Sponsors and Funding:
The research expedition is organized and funded mainly by ArcticNet and the Canadian Healthy Oceans network (CHONe project).

Purpose of Expedition:
On the expedition Maéva and the research team will document marine ecosystems found on the seabed and the impact of climate change. More specifically, the sea ice extent will be measured in order to understand how it affects the ocean ecosystems below. Because they don’t know precisely what’s there, it is difficult for the researchers to understand the ecosystemic impacts of climate change. This is why they intend to document what they observe.

This project is a collaboration between Dr. S. Kim Juniper’s lab at the University of Victoria (British Columbia) and Dr. Philippe Archambault’s laboratory at the Université du Québec à Rimouski (Quebec).

The site selection is related to the interest of ArcticNet and CHONe projects. These networks bring scientists together in Canada to understand marine ecosystems. The research team will participate in three dives with a remotely operated vehicle at three different sites. They hope to capture some video footage of living communities. They will also use box cores and trawls to get samples and identify the species.

Maéva will also film the expedition for various projects for three different populations: Inuit communities, the scientific community and the general public. Her images will be used for International Polar Year educational packages, as well as CHONe, ArcticNet and UVIC’s lab. Maéva hopes to document the interactions between Inuit communities and expedition scientists, and students from the Schools on Board program in relation to CCGS Amundsen scientists.

www.amundsen.ulaval.ca and www.amundsen.quebec-ocean.ulaval.ca

Polar Perspectives IPY Speaker Series & Youth Forums: Success!

POLAR PERSPECTIVES (www.nature.ca/polar) wrapped up on Friday, October 16, 2009. Since its launch at the Canadian Museum of Nature on April 1, 2008, the series traveled to 15 venues across the country, in each of Canada’s provinces and territories! This pan-Canada IPY event was supported by the Government of Canada’s International Polar Year Program, the Walter & Duncan Gordon Foundation, the Alliance of Natural History Museums of Canada, Students on Ice, the Royal Canadian Geographical Society, Canadian Geographic Magazine, the National Inuit Youth Council and the Canadian IPY Youth Steering Committee.

The Speaker Series consisted of an evening lecture program delivered to a general audience by prominent scientists, writers, artists, filmmakers, adventurers and leaders. Speakers gave audiences the latest knowledge on the IPY, Arctic issues and their impact on both the northern and southern Canadian population. Topics ranged from environmental and cultural issues in the north to recent polar research discoveries. A two-speaker format drew on local, national and international speakers. Each evening program included special presentations, contests, and IPY-related booths and displays.

The Youth Forums were full-day educational programs providing secondary school students with a unique opportunity to learn about Arctic ecosystems, northern issues, IPY, climate change, Antarctica, and much more. Video-conferencing throughout the Canadian Arctic enabled northern youth to share their thoughts, stories and perspectives with other northern and southern youth regarding Health, Culture, Climate Change, Conservation, Sovereignty and other topics. Participating students were tasked to answer such questions as “What does the Arctic mean to you?”, and challenged to make “IPY Commitments”.

The free public lectures were well attended and a variety of IPY speakers, including Dr. Louis Fortier, Director of ArcticNet; Dr. Elizabeth Peacock, Polar Bear Researcher for the Government of Nunavut; Geoff Green, Founder & Executive Director of Students on Ice; Karsten Heuer, Author of Being Caribou; as well as many other representatives from Canadian Museums, Universities and IPY projects. The most recent public presentations at the Royal Ontario Museum in Toronto we made by Dr. Peter J. Van Coeverden de Groot (“Inuit Role In The Monitoring of Polar Bears In The Face of Global Climate Change”) and Dr. James Drummond (“A PEARL Near the Pole: Atmospheric Research at the Top of the World”).

The Youth Forums have been a resounding success! Over 750 students have participated in 16 events! Participating students have learned a great deal about the polar regions, the IPY, and have been motivated and inspired to become more engaged and to explore further opportunities.

Polar Perspectives has received excellent media coverage across the country (CBC, CTV, various newspapers, print and electronic media).

Thank you to all series partners for making Polar Perspectives IPY Speaker Series & Youth Forums such a success!

For more information, please contact Tim Straka at tim (at) studentsonice (dot) com or 1-866-336-6423.

www.nature.ca/polar

Global surface temperature anomalies for the month of September 2009. (Credit: NOAA)

NOAA: Global Surface Temperature Was Second Warmest for September

NOAA (October 15, 2009) — The combined global land and ocean surface temperature was the second warmest September on record, according to NOAA’s National Climatic Data Center in Asheville, N.C. Based on records going back to 1880, the monthly National Climatic Data Center analysis is part of the suite of climate services NOAA provides.

NCDC scientists also reported that the average land surface temperature for September was the second warmest on record, behind 2005. Additionally, the global ocean surface temperature was tied for the fifth warmest on record for September.

Global Temperature Highlights

* The combined global land and ocean surface temperature was 1.12 degrees F above the 20th century average of 59.0 degrees F. Separately the global land surface temperature was 1.75 degrees F above the 20th century average of 53.6 degrees F.

* Warmer-than-average temperatures engulfed most of the world’s land areas during the month. The greatest warmth occurred across Canada and the northern and western contiguous United States. Warmer-than-normal conditions also prevailed across Europe, most of Asia and Australia.

* The worldwide ocean temperature tied with 2004 as the fifth warmest September on record, 0.90 degree F above the 20th century average of 61.1 degrees F. The near-Antarctic southern ocean and the Gulf of Alaska featured notable cooler-than-average temperatures.

Other Highlights

* Arctic sea ice covered an average 2.1 million square miles in September – the third lowest for any September since records began in 1979. The coverage was 23.8 percent below the 1979-2000 average, and the 13th consecutive September with below-average Arctic sea ice extent.

* Antarctic sea ice extent in September was 2.2 percent above the 1979-2000 average. This was the third largest September extent on record, behind 2006 and 2007.

* Typhoon Ketsana became 2009’s second-deadliest tropical cyclone so far, claiming nearly 500 lives across the Philippines, Cambodia, Laos and Vietnam. The storm struck the Philippines on September 26, leaving 80 percent of Manila submerged.

Scientists, researchers, and leaders in government and industry use NCDC’s monthly reports to help track trends and other changes in the world’s climate. The data have a wide range of practical uses, from helping farmers know what and when to plant, to guiding resource managers with critical decisions about water, energy and other vital assets.

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.

For more information, visit http://www.noaanews.noaa.gov/stories2009/20091015_sepglobalstats.html

Polar Bears in the Arctic are feeling the impacts of accelerating climate change.
(Photo Credit: Annelise Miska)

Arctic sees more signs of accelerating climate change

Greenbang (October 26, 2009) — North Pole Melt Ponds (NOAA)This past summer might have seen more Arctic sea ice cover than in 2007 or 2008, but scientists continue to see dramatic – and accelerating – signs of climate change in the region, according to the latest Arctic Report Card.

The annual assessment is a collaborative effort of 71 national and international scientists.

“The Arctic is a special and fragile place on this planet,” said Jane Lubchenco, undersecretary for oceans and atmosphere and an administrator with the National Oceanographic and Atmospheric Administration (NOAA). “Climate change is happening faster in the Arctic than any other place on Earth — and with wide-ranging consequences. When I visited the northern corners of Alaska’s Arctic region earlier this year, I saw an area abundant with natural resources, diverse wildlife, proud local and native peoples — and a most uncertain future. This year’s Arctic Report Card underscores the urgency of reducing greenhouse gas pollution and adapting to climate changes already under way.”

Among the changes highlighted in the 2009 update to the Arctic report card were:

* A change in large-scale wind patterns affected by the loss of summer sea ice;
* The replacement of multi-year sea ice by first-year sea ice;
* Warmer and fresher water in the upper ocean linked to new ice-free areas;
* A continued loss of the Greenland ice sheet;
* Less snow in North America and increased runoff in Siberia; and
* The effect of the loss of sea ice on Arctic plant, animal, and fish species.

The Arctic Report Card is an annual assessment that was introduced by NOAA’s Climate Programme Office in 2006. The report card established a baseline of conditions in the region at the beginning of the 21st century, and the annual updates track and monitor the often quickly-changing conditions in the Arctic. Using a color-coded system of red to indicate consistent evidence of warming and yellow to indicate mixed signals about warming from climate indicators and species, the report card is updated annually in October and tracks Arctic data in six categories: atmosphere, sea ice, biology, ocean, land, and conditions in Greenland.

“The Arctic we see today is very different from the Arctic we saw even five years ago,” said Jackie Richter-Menge of the USACE Cold Regions Research and Engineering Laboratory in Hanover, New Hampshire, and the report’s chief technical editor and contributing author. “It’s a warmer place with less thick and more mobile sea ice, warmer and fresher ocean water, and increased stress on caribou, reindeer, polar bears and walrus in some regions.”

The 2009 update to the report card reflects the contributions of an international team of 71 researchers from countries that include the US, Canada, UK Belgium, China, Denmark, Japan, The Netherlands and Russia.

For more information, visit http://www.greenbang.com/arctic-sees-more-signs-of-accelerating-climate-change_12319.html

Snow is shown on the San Bernardino mountians framed by four palm trees in Covina, California December 26, 2008. (REUTERS/Fred Prouser)

Palms grew in ice-free Arctic 50 million years ago: study

by Alister Doyle, Environment Correspondent

Reuters (October 26, 2009) Oslo — Palms flourished in the Arctic during a brief sweltering period about 50 million years ago, according to a study on Sunday that hints at big gaps in scientific understanding of modern climate change.

The Arctic “would have looked very similar to the vegetation we now see in Florida,” said Appy Sluijs of Utrecht University in the Netherlands who led an international study. Evidence of palms has never been found so far north before.

The scientists, sampling sediments on a ridge on the seabed that was about 500 km (300 miles) from the North Pole 53.5 million years ago, found pollens of ancient palms as well as of conifers, oaks, pecans and other trees.

“The presence of palm pollen implies that coldest month mean temperatures over the Arctic land masses were no less than 8 Celsius” (46.40F), the scientists, based in the Netherlands and Germany, wrote in the journal Nature Geoscience.

That contradicts computer model simulations — also used to predict future temperatures — that suggest winter temperatures were below freezing even in the unexplained hothouse period that lasted between 50,000 and 200,000 years in the Eocene epoch.

Palms are quickly killed by frost.

Sluijs said that it was also striking that palms, which do not lose their leaves in winter, grew in an area where the sun does not shine for about five months. Experiments with modern palms indicate that they can survive prolonged darkness.

SURPRISES

The scientists said that presence of palms — it was not clear if they were trees or plants — hinted that the modern climate system could yield big surprises.

Temperatures are now rising because of man-made greenhouse gases, mainly from burning fossil fuels, according to the U.N. Climate Panel. Arctic ice shrank in 2007 to its smallest size since satellite measurements began in the 1970s.

One possibility for the ancient spike in temperatures was an abrupt rise in carbon dioxide levels, to far beyond concentrations now. That might have been caused by volcanic eruptions, or a melt of frozen methane trapped in the seabed.

“We cannot explain this with the current knowledge of the climate system,” Sluijs said. One possibility was that new types of clouds formed in the Arctic as it warmed, acting as a blanket that trapped ever more heat and accelerated warming.

“If the ocean was very warm it’s possible that these clouds form at a higher latitude than now,” he said. Such effects caused by new cloud formation could be an unexpected tripwire in accelerating modern climate change.

More than 190 nations are due to meet in Copenhagen from December 7-18 to agree a new U.N. climate treaty to succeed the U.N.’s Kyoto Protocol.

For more information, visit http://in.reuters.com/article/lifestyleMolt/idINTRE59O1NK20091025

Photo: NASA Scientific Visualization Studio Collection

Arctic now traps 25 percent of World’s carbon — but that could change

United States Geological Survey (October 14, 2009) — The arctic could potentially alter the Earth’s climate by becoming a possible source of global atmospheric carbon dioxide. The arctic now traps or absorbs up to 25 percent of this gas but climate change could alter that amount, according to a study published in the November issue of Ecological Monographs.

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 has recently 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 instead, possibly make the Arctic a source of carbon dioxide.

“This study is another example of the important role played by USGS and its partners in providing the scientific research that must be the backbone of any actions related to climate change,” said Secretary of the Interior Ken Salazar.

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 organic matter decomposition, releasing more carbon dioxide into the atmosphere. Of greater concern, 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 dioxide.

“In the short term, warming temperatures could release more Arctic carbon to the atmosphere,” says McGuire. “And with permafrost thawing, there will be more available carbon to release.”

On the scale of a few decades, the thawing permafrost could also result in a more waterlogged Arctic, says McGuire, a situation that could encourage the activity of methane-producing organisms. Currently, the Arctic is a substantial source of methane to the atmosphere: as much as 50 million metric tons of methane are released per year, in comparison to the 400 million metric tons of carbon dioxide the Arctic stores yearly. But methane is a very potent greenhouse gas – about 23 times more effective at trapping heat than carbon dioxide on a 100-year time scale. If the release of Arctic methane accelerates, global warming could increase at much faster rates.

“We don’t understand methane very well, and its releases to the atmosphere are more episodic than the exchanges of carbon dioxide with the atmosphere,” says McGuire. “It’s important to pay attention to methane dynamics because of methane’s substantial potential to accelerate global warming.”

But uncertainties still abound about the response of the Arctic system to climate change. For example, the authors write, global warming may produce longer growing seasons that promote plant photosynthesis, which removes carbon dioxide from the atmosphere. Also, the expansion of shrubs in tundra and the movement of treeline northward could sequester more carbon in vegetation. However, increasingly dry conditions may counteract and overcome these effects. Similarly, dry conditions can lead to increased fire prevalence, releasing even more carbon.

McGuire contends that only specific regional studies can determine which areas are likely to experience changes in response to climate change.

“If the response of the arctic carbon cycle to climate change results in substantial net releases of greenhouse gases, this could compromise proposed mitigation efforts for controlling the carbon cycle,” he says.

The article, “Sensitivity of the Carbon Cycle in the Arctic to Climate Change”, will be in the November issue of Ecological Monographs. The coordinating lead author is David McGuire, USGS, and the co-authors include internationally renowned scientists from Canada, Germany, Sweden, and the United States. This study was sponsored by the Arctic Monitoring and Assessment Program, the Climate in the Cryosphere Program, and the International Arctic Science Committee.

USGS provides science for a changing world. For more information visit www.usgs.gov.

Ayr Lake on Baffin Island may hold the secrets to Arctic climate change. (Photo Credit: Jason Briner)

Baffin Island reveals dramatic scale of Arctic climate change

Study delves back into 200,000 years of history to demonstrate the devastating impact of global warming

by Steve Connor, Science Editor

Independent (October 20, 2009) — A frozen lake on a remote island off Canada’s northern coast has yielded remarkable insights into how the Arctic climate has changed dramatically over 50 years.

Muddy sediment from the bottom of the lake, some of it 200,000 years old, shows that Baffin Island, one of the most inhospitable places on Earth, has undergone an unprecedented warming over the past half-century. Scientists believe the temperature rise is probably due to human-induced warming. It has more than offset a natural cooling trend which began 8,000 years ago.

Instead of cooling at a rate of minus 0.2C every 1,000 years – a trend that was expected to continue for another 4,000 years because of well-known changes to the Earth’s solar orbit – Baffin Island, like the rest of the Arctic, has begun to get warmer, especially since 1950. The Arctic is now about 1.2C warmer than it was in 1900, confirming that the region is warming faster than most other parts of the world.

Baffin Island, the largest island in the Arctic Canadian Archipelago, is subjected to prevailing northerly winds that keep average temperatures at about minus 8.5C, well below similar Arctic locations at a comparable latitude. Polar bears, arctic fox and arctic hares walk the island’s territory while narwhal, walrus and beluga whale patrol its coastline.

The island is dotted with lakes, the bottoms of which have been periodically scoured by glaciers with each passing ice age. However, scientists have found that the sediments at the bottom of some of the lakes, which build up each year rather like tree rings, have survived this scouring process intact.

This has enabled the scientists to take core samples going back tens of thousands of years. One such lake on Baffin Island, known as CF8, has been found to have layers of sediment dating back 200,000 years, which makes it the oldest lake sediment bored from any glaciated parts of Canada or Greenland, according to the study published in the journal Proceedings of the National Academy of Sciences.

It is the CF8 lake that has provided scientists with the sediment core showing the unprecedented warming of Baffin Island over the past few decades, compared with a time span going back 200,000 years, a period which included two ice ages and three interglacial periods – and roughly the time that Homo sapiens has been on earth.

“The past few decades have been unique in the past 200,000 years in terms of the changes we see in the biology and chemistry recorded in the cores,” said Yarrow Axford of the University of Colorado at Boulder. “We see clear evidence for warming in one of the most remote places on earth at a time when the Arctic should be cooling because of natural processes.” The scientists found that certain cold-adapted organisms in the layers of sediment have decreased in frequency since about 1950. Larvae from species of Arctic midge, which only live in cold conditions, have abruptly declined and two species in particular have disappeared altogether.

Meanwhile, a species of lake alga or diatom that is better suited to warmer conditions has increased significantly over the same period, indicating longer periods when the lake’s surface was free of ice, the scientists said. Other sediment measurements support a dramatic reversal of the natural cooling trend, they said.

As part of a 21,000-year cycle, the Arctic has been receiving progressively less summertime energy from the Sun for the past 8,000 years because of a well-established “wobble” in the Earth’s solar rotation – the Earth is now 0.6 million miles further from the Sun during an Arctic summer solstice than it was in 1BC. This decline will not reverse for another 4,000 years, but changes to the climate of Baffin Island show that the cooling it should have caused has gone into reverse in the past few decades.

A separate team of scientists analysing Arctic lakes in Alaska found a similar warming trend in recent years compared to sediment records going back a few thousand years. They, too, concluded that the warming was unprecedented and could be explained by human activities, namely the build of man-made carbon dioxide in the atmosphere.

“The amount of energy we’re getting from the Sun in the 20th century continued to go down, but the temperature went up higher than anything we’ve seen in the last 2,000 years,” said Nicholas McKay of the University of Arizona in Tucson.

“The 20th century is the first century for which how much energy we’re getting from the Sun is no longer the most important thing governing the temperature of the Arctic,” said Dr McKay, when the study was published last month in the journal Science.

Baffin Island: An ancient trading post

*Baffin Island lies between Greenland and the northern coast of Canada and, for all its remoteness and inhospitable climate, it may have played an important role as a staging post on the first-ever transatlantic trade route.

Archaeologists have found wooden items and a length of yarn at Nunguvik in the south which they believe indicate that visiting Vikings were interacting with the local natives, known as the Dorset people, who lived on Baffin Island between 500BC and AD1500.

The scientists believe that the Dorset, who dressed in animal skins, did not know how to spin yarn, unlike the Vikings. The three-metre strand, found frozen in the tundra, was spun from arctic hare fur mixed with goat hair, similar to yarn found at Viking settlements on Greenland. There are no goats on Baffin Island.

Further evidence comes from one of the wooden carvings which shows two faces chin to chin. One has the features of indigenous North Americans, whose ancestors had an Asian origin, while the other shows a long, narrow face and nose with a heavy beard – a portrait perhaps of a visiting Viking.

For more information, visit http://www.independent.co.uk/environment/climate-change/baffin-island-reveals-dramatic-scale-of-arctic-climate-change-1805623.html