Arctic melt releasing ancient methane
By RICHARD BLACK - BBC NEWS - SCIENCE & ENVIRONMENT
Added: Sun, 20 May 2012 20:30:38 UTC
Many of the sites were bubbling methane that has been stored for millennia
Scientists have identified thousands of sites in the Arctic where methane that has been stored for many millennia is bubbling into the atmosphere.
The methane has been trapped by ice, but is able to escape as the ice melts.
Writing in the journal Nature Geoscience, the researchers say this ancient gas could have a significant impact on climate change.
Methane is the second most important greenhouse gas after CO2 and levels are rising after a few years of stability.
There are many sources of the gas around the world, some natural and some man-made, such as landfill waste disposal sites and farm animals.
Tracking methane to these various sources is not easy.
But the researchers on the new Arctic project, led by Katey Walter Anthony from the University of Alaska at Fairbanks (UAF), were able to identify long-stored gas by the ratio of different isotopes of carbon in the methane molecules.
Using aerial and ground-based surveys, the team identified about 150,000 methane seeps in Alaska and Greenland in lakes along the margins of ice cover.
Local sampling showed that some of these are releasing the ancient methane, perhaps from natural gas or coal deposits underneath the lakes, whereas others are emitting much younger gas, presumably formed through decay of plant material in the lakes.
"We observed most of these cryosphere-cap seeps in lakes along the boundaries of permafrost thaw and in moraines and fjords of retreating glaciers," they write, emphasising the point that warming in the Arctic is releasing this long-stored carbon.
Damian Carrington - The Observer 3 Comments
"In the long run, I would still be more concerned about the impact of climate change, but this work shows that even if we stabilise the climate, we might still get sea level rise due to how we use water."
- - BBC News - Science & Environment 6 Comments
An "annular eclipse" will be visible from a 240 to 300km-wide swathe of Earth stretching from Asia across the Pacific to the western US on Monday.
Sid Perkins - Science - AAAS.org 8 Comments
Did a comet wipe out woolly mammoths and an ancient Indian culture almost 13,000 years ago? Geologists have fiercely debated the topic since 2007. Now a new study says an extraterrestrial impact wasn't to blame, though the scientists who originally proposed the impact idea still aren't convinced.
Megan Scudellari - TheScientist 14 Comments
Melting Ice Releases Ancient Microbes
Living cells escaping from Antarctic glaciers could speed global warming and affect marine life.
MORE BY RICHARD BLACK
Richard Black - BBC News - Science &... 95 Comments
Funding came from a number of sources, including charitable foundations maintained by the Koch brothers, the billionaire US industrialists, who have also donated large sums to organisations lobbying against acceptance of man-made global warming.
Richard Black - BBC News - Science &... 66 Comments
The principle behind the idea is that high-altitude aerosols would cool the planet's surface by reflecting solar energy back into space, mimicking the effect of huge volcanic eruptions.
Richard Black - BBC News Science &... 16 Comments
Some shark species make "mental maps" of their home ranges, allowing them to pin-point destinations up to 50km (30 miles) away, research suggests.