Editor's Summary

28 May 2009

Permafrost carbon release

The enormous amounts of carbon stored deep in permafrost soils — permafrost ecosystems contain almost twice as much carbon as is present in the atmosphere — have the potential to create a positive feedback to climate change if released into a warming world. The bulk of the permafrost carbon pool consists of 'old' carbon, accumulated over thousands of years, but the rate of carbon release from these soils is highly uncertain. Schuur et al. report data on net ecosystem carbon exchange and the radiocarbon age of ecosystem respiration from a long-term monitoring site in Alaska where permafrost temperatures have been directly measured since 1985, and observed to warm since then. They find significant losses of soil carbon with permafrost thaw that, over decadal timescales, overwhelms increased plant carbon uptake at rates that could make permafrost a large biospheric carbon source in a warmer world.

Letter: The effect of permafrost thaw on old carbon release and net carbon exchange from tundra

Edward A. G. Schuur, Jason G. Vogel, Kathryn G. Crummer, Hanna Lee, James O. Sickman & T. E. Osterkamp

doi:10.1038/nature08031

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