Mongbay: The thawing of permafrost in northern latitudes will become a major source of greenhouse gas emissions, according to a new study that more than doubles previous estimates of the amount of carbon stored in the frozen soils of Alaska and Siberia. Writing in the September 2008 issue of BioScience, Edward A. G. Schuur of the University of Florida and colleagues show that melting permafrost “could release as “could amount to roughly half those resulting from global land-use change during …