Scientists used data on more than 9,000 soil samples from around the world, and found that carbon storage "declines strongly" as average temperatures increase.
This is an example of a “positive feedback”, where global warming causes more carbon to be released into the atmosphere, further accelerating climate change.
Importantly, the amount of carbon that could be released depends on the soil type, with coarse-textured (low-clay) soils losing three times as much carbon as fine-textured (clay-rich) soils.
The researchers, from the University of Exeter and Stockholm University, say their findings help to identify vulnerable carbon stocks and provide an opportunity to improve Earth System Models (ESMs) that simulate future climate change.
“Because there is more carbon stored in soils than there is in the atmosphere and all the trees on the planet combined, releasing even a small percentage could have a significant impact on our climate,” said Professor Iain Hartley of Exeter’s College of Life and Environmental Sciences.
“Our analysis identified the carbon stores in coarse-textured soils at high-latitudes (far from the Equator) as likely to be the most vulnerable to climate change.
Read more at: University of Exeter