Heatwaves Threaten 300 Gigatons From Permafrost as Fires Speed Irreversible Arctic Thaw
Updated
Updated · The Guardian · Aug 20
Heatwaves Threaten 300 Gigatons From Permafrost as Fires Speed Irreversible Arctic Thaw
2 articles · Updated · The Guardian · Aug 20
Summary
Heatwaves and wildfires are accelerating thaw across permafrost regions, raising the risk of local tipping points that can lock landscapes into decades or centuries of greenhouse-gas emissions.
1,500 gigatons of carbon are stored in permafrost—about three times all living vegetation—and 200 to 300 gigatons of CO2 equivalent could be released this century if warming reaches 1.8C to 3.6C.
20 million square kilometers of frozen ground span Siberia, Canada, Alaska and parts of Europe; once ice-rich soils collapse into lakes, wetlands or gullies, they are unlikely to recover for hundreds of years.
Several million square kilometers are already effectively doomed because thaw lags warming by decades, though limiting each degree of warming could still save about 4 million square kilometers from thawing.
Arctic warming is running up to four times the global average, and the professor said rapid emissions cuts—not geoengineering—are the only viable way to curb a self-reinforcing climate feedback.