Tag Archives: arctic permafrost

Arctic permafrost: sleeping giant, or ticking time bomb?

Arctic permafrost melting – a 2004 photo

For those with some understanding of the climate system, and the danger of amplifying feed backs (or positive feed backs) the CO2 and methane currently buried under the Arctic permafrost is of concern. Now it seems it is leaking – out gassing – in greater quantities. Science Daily reports

Permafrost (perennially frozen) soils underlie much of the Arctic. Each summer, the top layers of these soils thaw. The thawed layer varies in depth from about 4 inches (10 centimeters) in the coldest tundra regions to several yards, or meters, in the southern boreal forests. This active soil layer at the surface provides the precarious foothold on which Arctic vegetation survives. The Arctic’s extremely cold, wet conditions prevent dead plants and animals from decomposing, so each year another layer gets added to the reservoirs of organic carbon sequestered just beneath the topsoil.

Over hundreds of millennia, Arctic permafrost soils have accumulated vast stores of organic carbon — an estimated 1,400 to 1,850 petagrams of it (a petagram is 2.2 trillion pounds, or 1 billion metric tons). That’s about half of all the estimated organic carbon stored in Earth’s soils. In comparison, about 350 petagrams of carbon have been emitted from all fossil-fuel combustion and human activities since 1850. Most of this carbon is located in thaw-vulnerable topsoils within 10 feet (3 meters) of the surface.

But, as scientists are learning, permafrost — and its stored carbon — may not be as permanent as its name implies. And that has them concerned.

“Permafrost soils are warming even faster than Arctic air temperatures — as much as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30 years,” Miller said. “As heat from Earth’s surface penetrates into permafrost, it threatens to mobilize these organic carbon reservoirs and release them into the atmosphere as carbon dioxide and methane, upsetting the Arctic’s carbon balance and greatly exacerbating global warming.”

Current climate models do not adequately account for the impact of climate change on permafrost and how its degradation may affect regional and global climate. Scientists want to know how much permafrost carbon may be vulnerable to release as Earth’s climate warms, and how fast it may be released.

Research is under way:

CARVing Out a Better Understanding of Arctic Carbon

Enter CARVE. Now in its third year, this NASA Earth Ventures program investigation is expanding our understanding of how the Arctic’s water and carbon cycles are linked to climate, as well as what effects fires and thawing permafrost are having on Arctic carbon emissions. CARVE is testing hypotheses that Arctic carbon reservoirs are vulnerable to climate warming, while delivering the first direct measurements and detailed regional maps of Arctic carbon dioxide and methane sources and demonstrating new remote sensing and modeling capabilities. About two dozen scientists from 12 institutions are participating.

“The Arctic is warming dramatically — two to three times faster than mid-latitude regions — yet we lack sustained observations and accurate climate models to know with confidence how the balance of carbon among living things will respond to climate change and related phenomena in the 21st century,” said Miller. “Changes in climate may trigger transformations that are simply not reversible within our lifetimes, potentially causing rapid changes in the Earth system that will require adaptations by people and ecosystems.”

Image source: Arctic Science Journeys

Tagged , , , , ,

Front page climate change news? The Age gets it right on permafrost story

Those of us attempting to communicate the risks associated with climate change often lament the lack of “serious” media coverage.

While climate change is frequently mentioned in the op-ed sections of Australia’s papers (and if a News Limited publication the stance is invariably skeptical) it is rare to see climate change make front page news.

Which is why I was impressed to see The Age today – the headline, At the edge of disastersays it all:

THE world is on the cusp of a “tipping point” into dangerous climate change, according to new data gathered by scientists measuring methane leaking from the Arctic permafrost and a report presented to the United Nations on Tuesday.

Journalist Ben Cubby should be congratulated on his story, especially getting it onto page one at time when every other paper is pursuing the faux-scandal that is the Gillard-AWU affair.

The story is about one of the more worrying climate related tipping points; the release of the vast stores of methane under the Arctic permafrost.

Methane is a more potent greenhouse gas than carbon, and has been of concern for several years now as this 2009 New Scientist article alludes:

I AM shocked, truly shocked,” says Katey Walter, an ecologist at the University of Alaska in Fairbanks. “I was in Siberia a few weeks ago, and I am now just back in from the field in Alaska. The permafrost is melting fast all over the Arctic, lakes are forming everywhere and methane is bubbling up out of them.”

Back in 2006, in a paper in Nature, Walter warned that as the permafrost in Siberia melted, growing methane emissions could accelerate climate change. But even she was not expecting such a rapid change. “Lakes in Siberia are five times bigger than when I measured them in 2006. It’s unprecedented. This is a global event now, and the inertia for more permafrost melt is increasing.”

What does this mean?

Simply put – it may imply warming is happening faster than anyone anticipated:

Now it appears that the assessment was too optimistic. The latest data from across the globe show that the planet is changing faster than expected. More sea ice around the Arctic Ocean is disappearing than had been forecast. Regions of permafrost across Alaska and Siberia are spewing out more methane, the potent greenhouse gas, than models had predicted.

Ice shelves in West Antarctica are breaking up more quickly than once thought possible, and the glaciers they held back on adjacent land are sliding faster into the sea.

Extreme weather events, such as floods and the heat wave that gripped much of the U.S. in the summer of 2012 are on the rise, too. The conclusion? “As scientists, we cannot say that if we stay below two degrees of warming everything will be fine,” says Stefan Rahmstorf, a professor of physics of the oceans at the University of Potsdam in Germany.

In my mind this is one of the most worrying tipping points (search WtD blog for “clathrate gun hypothesis”).

For some time it has been one of the things that terrify – yes terrify – me:

So let me state this: it is now pointless wrangling over the question of whether or not to attribute individual events to climate change.

Reality makes that debate redundant.

We’re here: we’ve arrived at the point in history when our species has engineered a new climate. The point we knew was coming – that was inevitable – if we did nothing.  

Tagged , , , , ,
%d bloggers like this: