Climate: Permafrost thaw doubles carbon losses

Study says greening tundra won’t offset permafrost meltdown

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Study says new plant growth won’t compensate for carbon emissions from melting tundra in the Arctic. bberwyn photo.

Staff Report

FRISCO — Permafrost could dwindle by 30 to 70 percent by the end of the century, and more vegetation in the Arctic won’t be enough to offset the carbon emissions from thawing organic soils.

Scientists with the Woods Hole Research Center reached their conclusions after a series of field tests designed to measure net gains or losses in carbon emissions. The study is published in the journal Ecology.

“Our results show that while permafrost degradation increased carbon uptake during the growing season, in line with decadal trends of ‘greening’ tundra, warming and permafrost thaw also enhanced winter respiration, which doubled annual carbon losses,” said WHRC assistant scientist Sue Natali. Continue reading

Despite global warming, new permafrost forming

New permafrost is forming around Alaska's Twelvemile Lake.

A USGS study finds new permafrost forming near Alaska’s Twelvemile Lake.

Small local variations in temperatures eyed as factor

Staff Report

FRISCO — Scientists with the U.S. Geological Survey say they’ve found new patches of permafrost forming in the margins a retreating lake in the interior of Alaska. The findings run counter the conventional wisdom that permafrost will shrink and disappear as the Earth’s climate warms — but don’t jump on the happy train just yet.

The new permafrost patches are small and suggest that the areas of frozen soil are sensitive to small temperature variations and other local factors, the USGS-led study suggests. Especially important is emerging vegetation around the edge of the lake. Thick willows shade the ground to the point that the soil can freeze, the scientists said. Continue reading

Climate models underestimating Arctic permafrost methane emissions

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Methane from melt ponds in the Canadian Arctic are a significant source of greenhouse gases. bberwyn photo.

Study targets small melt ponds in Canadian Arctic

By Summit Voice

FRISCO — When it comes to global warming, size can matter — in unexpected ways — according to scientists who studied methane emissions from thawing permafrost in the Canadian Arctic.

The findings suggest that most climate models are underestimating those emissions, and that including greenhouse gases coming from small thaw ponds could have a significant impact on climate. Continue reading

Study shows rapid retreat of Antarctic permafrost

‘It’s melting faster each time we measure’

Antarctica permafrost

Antarctic permafrost is melting at an accelerating rate. bberwyn photo.

By Summit Voice

FRISCO — While the massive ice cap covering much of Antarctica isn’t likely to melt down anytime soon, the fringes of the frozen continent are showing signs of wear and tear as the planet heats up.

Scientists making long-term measurements of permafrost in the McMurdo Dry Valleys region say permafrost is melting at an accelerating rate. Between 2001 and 2012, the rate rose to about 10 times the valley’s average during the present geologic epoch.

“The big tell here is that the ice is vanishing — it’s melting faster each time we measure,” said Joseph Levy, a research associate at The University of Texas at Austin’s Institute for Geophysics. “This is a dramatic shift from recent history,” Levy said, explaining there are no signs in the geologic record that the valley’s ground ice has retreated similarly in the past. Continue reading

What’s the climate tipping point for permafrost?

Cave study offers clues on temperature threshold

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Global permafrost is a significant factor in the climate-change equation. Map courtesy United Nations Environmental Program.

By Summit Voice

SUMMIT COUNTY — Climate scientists have long been warning that a meltdown of Arctic permafrost will trigger a spike in greenhouse gas emissions as long-frozen organic soils give up their carbon to the atmosphere. What’s not yet clear is how fast and how much of the permafrost will melt, but a new study helps identify a temperature threshold that could lead to widespread melting.

A team led by Oxford University scientists studied stalactites and stalagmites in caves along Siberia’s permafrost frontier, where the ground begins to be permanently frozen in a layer tens to hundreds of meters thick.

The stalactites and stalagmites only grow when liquid rainwater and snow melt drips into the caves. The formations record 500,000 years of changing permafrost conditions, including warmer climate periods. After studying the paleoclimate clues in the caves, the researchers concluded that another 1.5 degrees of warming would be enough to cause substantial thawing of permafrost far north from its present-day southern limit. Continue reading

Climate: Study IDs new permafrost threat

Study suggests direct sunlight can trigger CO2 emissions from disturbed permafrost soils

USGS researchers make ground-based permafrost measurements in Alaska.

USGS researchers make ground-based permafrost measurements in Alaska.

By Summit Voice

SUMMIT COUNTY — Along with melting ice — one of the more obvious signs of global warming in the Arctic — the region is changing in other ways.

In some areas, long-frozen soils are melting and collapsing, forming potholes and other new landscape features, and the ancient carbon locked into those soils is extremely sensitive to sunlight. When it’s exposed, it releases heat-trapping carbon dioxide gas into the atmosphere much faster than previously thought, according to University of Michigan ecologist and aquatic biogeochemist George Kling.

Climate scientists have long known that melting permafrost will release huge amounts of CO2, but the new findings suggest that exposure to sunlight will speed the process. Continue reading

Global warming: USGS researchers quantify potential greenhouse gas releases from melting Arctic permafrost

Staggering amounts of nitrogen and carbon could lead to runaway warming in coming decades

Permafrost melting is expected to increase in coming decades.

By Summit Voice

FRISCO — Scientists with the U.S. Geological Survey say they’ve quantified the amount of greenhouse gases that could be released into the atmosphere as Arctic permafrost starts to melt.

“This study quantifies the impact on Earth’s two most important chemical cycles, carbon and nitrogen, from thawing of permafrost under future climate warming scenarios,” said USGS Director Marcia McNutt. “While the permafrost of the polar latitudes may seem distant and disconnected from the daily activities of most of us, its potential to alter the planet’s habitability when destabilized is very real.”

As much as 44 billion tons of nitrogen and 850 billion tons of carbon could be released into the environment as the region begins to thaw over the next century. This nitrogen and carbon are likely to impact ecosystems, the atmosphere, and water resources including rivers and lakes. For context, this is roughly the amount of carbon stored in the atmosphere today. Continue reading

Global warming: Pinpointing permafrost methane emissions

USGS researchers make ground-based permafrost measurements in Alaska.

New study will generate important data on Arctic carbon cycle

By Summit Voice

SUMMIT COUNTY — Methane emissions from Arctic landscapes remain one of the big wild cards in the global warming deck, with some dire predictions that methane from melting permafrost could significantly increase warming.

There has been relatively little sampling in the area, but a research mission led by scientists from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association (AWI) and the GFZ German Research Centre for Geosciences has recently completed airborne measurements that will help establish a baseline for methane and calculate future increases. Continue reading

Global warming: Tracking permafrost meltdown

Satellite measurements by the European Space Agency suggest that a permafrost meltdown may be starting.

European satellite monitoring measuring changes in permafrost regions

By Summit Voice

SUMMIT COUNTY —One of the biggest concerns related to global warming is that rapid permafrost melting in northern latitudes could release a massive surge of additional carbon dioxide into the atmosphere.

It’s not clear whether such a meltdown tipping point is imminent, but the satellite record suggests the process has started, according to researchers who gathered recently at a permafrost workshop at the Alfred Wegener Institute in Potsdam, Germany.

Research presented at the conference indicates that satellites are seeing changes in land surfaces in high detail at northern latitudes, suggesting thawing permafrost. Data from satellite monitoring by the European Space Agency was a key part of the conference findings.

Permafrost is ground that remains at or below 32 degrees for at least two consecutive years and usually appears in areas at high latitudes such as Alaska, Siberia and Northern Scandinavia, or at high altitudes like the Andes, Himalayas and the Alps. Continue reading

Global warming: Permafrost meltdown causing problems

A major rock avalanche in the Bregaglia after Christmas 2011 could be a result of temperature rise in permafrost areas. PHOTO COURTESY HELI BERNINA.

New mapping tool to help land-use planners and public safety officials locate potential trouble spots

By Summit Voice

SUMMIT COUNTY — While permafrost is most often associated with the Arctic north, it’s also an important component of alpine ecosystems, serving as a sort of glue that holds otherwise crumbly mountains together.

As the Earth warms rapidly due to the buildup of greenhouse gases in the atmosphere, some alpine countries have already had first-hand experience with thawing permafrost as a result of climate change. In some mountain locations, cable-car and powerline pylons have become unstable, and f temperatures continue to rise, the problem will intensify in many places. Continue reading

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