When Permafrost Melts, What Happens to All That Stored Carbon?
The Arctic’s frozen ground contains large stores of organic carbon that have been locked in the permafrost for thousands of years. As global temperatures rise, that permafrost is starting to melt, raising concerns about the impact on the climate as organic carbon becomes exposed. A new study is shedding light on what that could mean for the future by providing the first direct physical evidence of a massive release of carbon from permafrost during a warming spike at the end of the last ice age.
The study, published this week in the journal Nature Communications, documents how Siberian soil once locked in permafrost was carried into the Arctic Ocean during that period at a rate about seven times higher than today.
“We know the Arctic today is under threat because of growing climate warming, but we don’t know to what extent permafrost will respond to this warming. The Arctic carbon reservoir locked in the Siberian permafrost has the potential to lead to massive emissions of the greenhouse gases carbon dioxide and methane to the atmosphere,” said study co-author Francesco Muschitiello, a post-doctoral research fellow at Columbia University’s Lamont-Doherty Earth Observatory.
To understand how melting permafrost influenced the carbon cycle in the past, the scientists examined the carbon levels in sediment that accumulated on the seafloor near the mouth of the Lena River about 11,650 years ago, when the last glacial period was ending and temperatures in the Northern Hemisphere spiked by several degrees.
Continue reading at The Earth Institute at Columbia University
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