Permafrost More Powerful than Previously Thought
06.07.2009 - Land & Geology, Flora & Fauna, Other, Arctic
A new paper published in Global Biogeochemical Cycles has shown that there is twice as much carbon stored in permafrost at high latitudes than previously thought. If the vast quantities of methane and carbon dioxide are released into the atmosphere, it could lead to positive feedback loop, significantly increasing global temperatures before the end of this century.
Dr. Pep Canadell, Director of the Global Carbon Project, says that projections show that that "almost all near-surface permafrost will disappear by the end of this century exposing large carbon stores to decomposition and release of greenhouse gases." Models developed in collaboration with Dr. Candrell indicate that global warming could trigger an irreversible process of thawing, increasing microbial activity, which "would lead to sustained long-term chronic emissions of carbon dioxide and methane," and the formation of thermokarst lakes, which could draw heat to deeper layers of soil and bring more methane to the surface.
Only a small amount of permafrost would need to melt for a significant feedback to begin and have and impact on temperature. "If only 10 per cent of the permafrost melts, the resultant feedback could result in an additional 80 ppm carbon dioxide equivalent released into the atmosphere, equating to about 0.7°C of global warming," said Dr. Candrell.
