Ancient permafrost quickly transforms to carbon dioxide upon thaw
Huge stores of organic carbon in permafrost soils -- frozen for hundreds to tens of thousands of years across high northern latitudes worldwide -- are currently isolated from the modern day carbon cycle. However, if thawed by changing climate conditions, wildfire, or other disturbances, this massive carbon reservoir could decompose and be emitted as the greenhouse gases carbon dioxide and methane, or be carried as dissolved organic carbon to streams and rivers.
"Many scientists worldwide are now investigating the complicated potential end results of thawing permafrost," said Rob Striegl, USGS scientist and study co-author. "There are critical questions to consider, such as: How much of the stored permafrost carbon might thaw in a future climate? Where will it go? And, what are the consequences for our climate and our aquatic ecosystems?"
http://www.sciencedaily.com/releases/2015/10/151026171407.htm