Greenhouse Gas Bubbling from Melting Permafrost Feeds Climate Warming at Much Higher Than Expected Rates

September 6, 2006

A study co-authored by a Florida State University scientist and published in the Sept. 7 issue of the journal Nature has found that as the permafrost melts in North Siberia due to climate change, carbon sequestered and buried there since the Pleistocene era is bubbling up to the surface of Siberian thaw lakes and into the atmosphere as methane, a greenhouse gas 20 times more potent than carbon dioxide.

In turn, that bubbling methane held captive as carbon under the permafrost for more than 40,000 years is accelerating global warming by heating the Earth even more --- exacerbating the entire cycle. The ominous implications of the process grow as the permafrost decomposes further and the resulting lakes continue to expand, according to FSU oceanography Professor Jeff Chanton and study co-authors at the University of Alaska-Fairbanks.

"This is not good for the quality of human life on Earth," Chanton said.

The researchers devised a novel method of measuring ebullition (bubbling) to more accurately quantify the methane emissions from two Siberian thaw lakes and in so doing, revealed the world's northern wetlands as a much larger source of methane release into the atmosphere than previously believed. The magnitude of their findings has increased estimates of such emissions by 10 to 63 percent.

Understanding the contribution of North Siberia thaw lakes to global atmospheric methane is critical, explains the paper that appears in this week's Nature, because the concentration of that potent greenhouse is highest at that latitude, has risen sharply in recent decades and exhibits a significant seasonal jump at those high northern latitudes.

Chanton points to the thawing permafrost along the margins of the thaw lakes -- which comprise 90 percent of the lakes in the Russian permafrost zone -- as the primary source of methane released in the region. During the yearlong study, he performed the isotopic analysis and interpretation to determine the methane's age and origin and assisted with measurements of the methane bubbles' composition to shed light on the mode of gas transport.

"My fellow researchers and I estimate that an expansion of these thaw lakes between 1974 and 2000, a period of regional warming, increased methane emissions by 58 percent there," said Chanton. "Because the methane now emitted in our study region dates to the Pleistocene age, it's clear that the process, described by scientists as 'positive feedback to global warming,' has led to the release of old carbon stocks once stored in the permafrost."

In addition to Chanton, the John Widmer Winchester Professor of Oceanography at FSU, co-authors of "Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming" include K. M. Walter (Institute of Arctic Biology, University of Alaska-Fairbanks); S. A. Zimov (Northeast Science Station, Cherskii, Russia); and D. Verbyla (Forest Science department, University of Alaska-Fairbanks).

Source: Florida State University

Explore further: Methane in Arctic lake traced to groundwater from seasonal thawing

Related Stories

Study measures methane release from Arctic permafrost

August 22, 2016

A University of Alaska Fairbanks-led research project has provided the first modern evidence of a landscape-level permafrost carbon feedback, in which thawing permafrost releases ancient carbon as climate-warming greenhouse ...

Large and increasing methane emissions from northern lakes

January 4, 2016

Methane is increasing in the atmosphere, but many sources are poorly understood. Lakes at high northern latitudes are such a source. However, this may change with a new study published in Nature Geoscience. By compiling previously ...

Defrosting the world's freezer—thawing permafrost

June 14, 2017

Snowy peaks rise up in one direction; boggy tundra spreads across the other. Fuzzy heads of long-stemmed plants sway in the wind, interspersed with bog blueberries. This is Alaska's Eight Mile Lake, where the nearest town ...

Team pioneers new way to survey thawing Arctic

January 31, 2013

(Phys.org)—In the snow of Alaska, a Stanford-led team of researchers has found a new way to determine if the soil beneath lakes, normally frozen, is thawing as a result of climate change. If so, the lakes could become a ...

Recommended for you

Mountain glaciers shrinking across the West

October 22, 2017

Until recently, glaciers in the United States have been measured in two ways: placing stakes in the snow, as federal scientists have done each year since 1957 at South Cascade Glacier in Washington state; or tracking glacier ...

Carbon coating gives biochar its garden-greening power

October 20, 2017

For more than 100 years, biochar, a carbon-rich, charcoal-like substance made from oxygen-deprived plant or other organic matter, has both delighted and puzzled scientists. As a soil additive, biochar can store carbon and ...

Cool roofs have water saving benefits too

October 20, 2017

The energy and climate benefits of cool roofs have been well established: By reflecting rather than absorbing the sun's energy, light-colored roofs keep buildings, cities, and even the entire planet cooler. Now a new study ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.