Joe Romm: Siberian permafrost at 30 feet warmed a remarkable 1.6°F in 10 years. The permafrost is soil that stays below freezing for at least two years. Permafrost warming “amplifies global climate change, because when frozen sediments thaw it unlocks soil organic carbon,” warns the study in the journal Nature Communications.
Plants capture CO2 from the air during photosynthesis, releasing that carbon into the atmosphere after dying. Arctic permafrost acts like a large carbon freezer — and the decomposition rate is very low.
Or, rather, it was. Humanity is leaving the freezer door wide open, and the tundra is being transformed from a long-term carbon locker to a short-term carbon un-locker. Alaskan tundra is warming so quickly it had become a net emitter of CO2. That study was the first to report a major portion of the Arctic had become a net source of heat-trapping emissions.