The most dangerous climate feedback loop is speeding up
In Siberia, the carbon-rich permafrost warmed by 1.6°F in just the last decade.
The carbon-rich permafrost warmed “in all permafrost zones on Earth” from 2007 to 2016, according to a new study.
Most ominously, Siberian permafrost at depths of up to 30 feet warmed a remarkable 1.6°F (0.9°C) in those 10 years, the researchers found. The permafrost, or tundra, is soil that stays below freezing (32°F) for at least two years.
Permafrost warming can “amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon,” warns the study, which was released Wednesday by the journal Nature Communications.
The thawing releases not only carbon dioxide but also methane (CH4) — a far more potent greenhouse gas — thereby further warming the planet. And as the planet continues to warm, more permafrost will melt, releasing even more greenhouse gases in a continuous feedback loop.
Thawing permafrost is an especially dangerous amplifying feedback loop because the global permafrost contains twice as much carbon as the atmospheredoes today .
Normally, plants capture CO2 from the air during photosynthesis and slowly release that carbon back into the atmosphere after they die. But the Arctic permafrost acts like a very large carbon freezer — and the decomposition rate is very low. Or, rather, it was.
Humanity is leaving the freezer door wide open. As a result, the tundra is being transformed from a long-term carbon locker to a short-term carbon un-locker.
A 2017 study found the Alaskan tundra is warming so quickly it had become a net emitter of CO2 ahead of schedule. That study was the first to report a major portion of the Arctic had already become a net source of heat-trapping emissions.
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