New climate change research from Northern Arizona University predicts frozen soils will release huge stores of ancient carbon as they warm.
The research team artificially warmed a plot of soil in Alaska for three years. They found the carbon released to the air as a result of the warming had been stored underground for hundreds or thousands of years.
Ted Schuur is an NAU professor and coauthor of the new study. He compares heating up permafrost to losing power in a freezer.
“If you don’t have power the food starts to rot, and the same thing’s happening with the carbon that’s frozen in the permafrost,” he said. “When it thaws, then the bacteria and fungi can eat it, and turn it into greenhouse gases.”
In the short term, plants mask the effect. They respond to the warmth by growing faster, and that puts carbon back into the soil. But Schuur said the ecosystem soon reaches a tipping point, when plants can’t keep up anymore. The end result is more carbon in the air — and that makes climate change speed up.
This ongoing experiment is one of the first to measure the age of the lost carbon, as well as the amount. The study appeared last month in Nature Climate Change.