by Deep Green Resistance News Service | Apr 22, 2012 | Climate Change
By Michael Marshall / NewScientist
As Arctic sea ice breaks apart, massive amounts of methane could be released into the atmosphere from the cold waters beneath.
High concentrations of the greenhouse gas have been recorded in the air above cracks in the ice. This could be evidence of yet another positive feedback on the warming climate – leading to even faster Arctic warming.
The Arctic is home to vast stores of methane – there are billions of tonnes of methane in permafrost alone. It is a potent greenhouse gas, so a major methane release would greatly accelerate climate change. The gas is found in icy crystals called hydrates beneath the shallow seas that flood some areas of the continental crust, as well as in permafrost. It is also being released from Arctic wetlands.
But this doesn’t explain why Eric Kort of the Jet Propulsion Laboratory in Pasadena, California, and his colleagues found patches of methane in remote regions of the Arctic Ocean, far from any of these known methane sources.
The team found the patches during five flights over the Arctic Ocean between 2009 and 2010, as part of a project to systematically map greenhouse gas levels in the atmosphere.
Kort estimates that, in the methane-rich regions, about 2 milligrams of the gas were being released per square metre of ocean every day. Some of the patches were close to the oil and gas plants in Prudhoe Bay, Alaska, but prevailing wind directions make these plants an unlikely source of the release.
Gassy ocean
So where does the gas come from? Since the 1970s, scientists have known that ocean surface waters are rich in methane. It seems to be made by marine bacteria trying to survive in waters that don’t have many nutrients in the form of nitrates. “This source appears to be a likely candidate to explain what we observed,” Kort says.
Water in the Arctic Ocean doesn’t mix well, so the water near the surface tends to remain there. Consequently, the methane ends up trapped near the surface. In other oceans, it would get broken down through reaction with oxygen or consumed by methanotrophic bacteria, but the cold weather helps to preserve it.
Kort saw methane releases close to cracks in the sea ice, or in places where the ice had broken up. This could be because methane only escapes from agitated water, says Ellen Damm of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany. This agitation is most likely to occur when autumn sets in and ice crystals start forming in the water, creating turbulence.
Hotter and hotter
The findings will need to be replicated, says Euan Nisbet, an earth scientist at Royal Holloway, University of London. But if the leak is widespread across the Arctic, this mechanism could prove to be a significant source of greenhouse gas.
“We know the Arctic is warming very fast indeed,” Nisbet says. And as the warming climate leads to more breaks in the sea ice, more ice-surrounded patches of open water will be able to release their methane, further accelerating global warming.
The question now is: how significant will this new effect on warming be? “It might be small,” Nisbet says, “or it could be another serious problem.”
From NewScientist: http://www.newscientist.com/article/dn21733-arctic-methane-leaks-threaten-climate.html
by Deep Green Resistance News Service | Mar 3, 2012 | Climate Change
By The State Column
A new study conducted by NASA finds that Arctic ice is melting at a rate far faster than previously expected, increasing the rate of release of a number of deadly chemicals.
The study, published and conducted by NASA’s Goddard Space Flight Center, finds the oldest and thickest arctic sea ice is disappearing faster than younger and thinner ice at the edges, leading to the release of certain chemicals.
The average thickness of the arctic sea ice cover is declining because it is rapidly losing its thick component, the multiyear ice,” said NASA scientists in a statement. “At the same time, the surface temperature in the arctic is going up, which results in a shorter ice-forming season.
NASA officials found that the extent of perennial ice, ice that has survived at least one summer, is shrinking at a rate of 12.2 percent per decade, while its area is declining at a rate of 13.5 percent per decade. The rate of melt is the highest yet recorded by NASA.
The study is the first to identify older sea ice as more vulnerable than new sea ice. Older sea ice usually survives the summer, rebuilding on itself as winter arrives.
Among the issues identified by NASA includes an accelerating release of chemicals into the atmosphere. Drastic reductions in Arctic sea ice in the last decade may intensify the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, said NASA researchers.
The study was launched with the aim of examining the nature of bromine explosions, which were first observed more than 20 years ago in Canada’s Arctic regions. The scientists “wanted to find if the explosions occur in the troposphere or higher in the stratosphere,” said NASA scientists.
The climate scientists said that melting Arctic sea ice is being replaced by a thinner and saltier ice, which releases bromine into the air when it interacts with sunlight and cold. That in turn triggers a chemical reaction called a “bromine explosion” that turns gaseous mercury in the atmosphere into a toxic pollutant that falls on snow, land and ice and can accumulate in fish.
The study is likely to rekindle the debate on limiting carbon dioxide and other greenhouse gases into the air. Already a number of various international agencies have sought to curtail the release of deadly compounds related to global warming, warning that an increase in the average temperature of the earth could have unforeseen consequences.
“Shrinking summer sea ice has drawn much attention to exploiting Arctic resources and improving maritime trading routes,” said the U.S. space agency. “But the change in sea ice composition also has impacts on the environment. Changing conditions in the Arctic might increase bromine explosions in the future.”
Read more from The State Column
by Deep Green Resistance News Service | Feb 13, 2012 | Climate Change
By Jeremy Hance / mongabay.com
Last year the Arctic, which is warming faster than anywhere else on Earth due to global climate change, experienced its warmest twelve months yet. According to recent data by NASA, average Arctic temperatures in 2011 were 2.28 degrees Celsius (4.1 degrees Fahrenheit) above those recorded from 1951-1980. As the Arctic warms, imperiling its biodiversity and indigenous people, researchers are increasingly concerned that the region will hit climatic tipping points that could severely impact the rest of the world. A recent commentary in Nature Climate Change highlighted a number of tipping points that keep scientists awake at night.
“If set in motion, [tipping points] can generate profound climate change which places the Arctic not at the periphery but at the core of the Earth system,” Professor Duarte, a climatologist with the University of Western Australia’s Ocean Institute and co-author other paper, said in a press release. “There is evidence that these forces are starting to be set in motion. This has major consequences for the future of human kind as climate change progresses.”
One of the tipping points is sea ice loss. The Arctic wasn’t just relatively hot last year—beating the previous record set in 2010 by 0.17 degrees Celsius (0.3 degrees Fahrenheit)—it also experienced the lowest sea ice volume yet recorded, and the second-lowest extent. Sea ice is essential to many Arctic species, from polar bears to walrus, and narwhals to seals. In just over 30 years, sea ice volume has dropped precipitously, declining by 76 percent from 1979 (16,855 cubic kilometers) to 2011 (4,017 cubic kilometers). This loss of sea ice also leads to greater regional and global warming, as the Arctic’s sea reflects the sun’s light back into space, cooling not only the region but the world.
Sea ice loss may also be having a direct impact on weather in the mid-latitudes. In fact, recent research has suggested that, perhaps unintuitively, the extreme cold spell experienced by Europe this winter was linked to the sea ice decline in the Arctic. Researchers argue that the Arctic Oscillation, which is partially responsible for weather conditions in the Northern Hemisphere in winter, has become unhinged by the sea ice decline, causing more extreme winters, such as Europe’s cold spell and the massive blizzards that hit the U.S. in 2009 and 2010.But it’s not just sea ice loss that has produced stark concerns: greenhouse gases from thawing permafrost could be just as disastrous. A study published in Nature late last year warned that greenhouse gas emissions due to permafrost thaw could equal the amount currently emitted by deforestation worldwide, a significantly larger estimate than has been put forward before. Moreover, since permafrost thaw emissions include methane, a more potent greenhouse gas than carbon, it could have an impact 2.5 times larger than deforestation overall.
“The larger estimate is due to the inclusion of processes missing from current models and new estimates of the amount of organic carbon stored deep in frozen soils,” co-author Benjamin Abbott, a University of Alaska Fairbanks graduate student, explained in a press release. “There’s more organic carbon in northern soils than there is in all living things combined; it’s kind of mind boggling.”
University of Florida researcher Edward Schuur says he doesn’t expect permafrost greenhouse gas emission to trump anthropogenic (human-caused) greenhouse gas emissions anytime soon, however they could become “an important amplifier of climate change.”
Further tipping points include an input of freshwater into the Atlantic Ocean from melting ice and glaciers, already increased by 30 percent, which Durate says “may affect the whole ocean current system and, as a result, the climate at a regional level.”Governments have responded to warming in the Arctic with a resource race. Governments with Arctic territories plan to drastically expand oil and gas exploitation, utilize new shipping routes, and increase mining. The industrialization of the Arctic, according to Duarte, may only accelerate impacts on the fragile region and push tipping points.
“[Arctic tipping points] represents a test of our capacity as scientists, and as societies to respond to abrupt climate change,” Duarte said. “We need to stop debating the existence of tipping points in the Arctic and start managing the reality of dangerous climate change. We argue that tipping points do not have to be points of no return. Several tipping points, such as the loss of summer sea ice, may be reversible in principle—although hard in practice. However, should these changes involve extinction of key species—such as polar bears, walruses, ice-dependent seals and more than 1,000 species of ice algae—the changes could represent a point of no return.”
The solution, Durate says, is to cut the fossil fuel emissions that are causing climate change.
