Argonne team unravels mysteries of carbon release in permafrost soils
Permafrost-affected soils — where subsurface temperatures remain below freezing for two or more consecutive years — contain vast amounts of organic carbon that decompose and enter the atmosphere. The rate of such release has accelerated with climate change as the regions rapidly grow warmer and surface soils thaw to greater depths in summer. The release of stored carbon as greenhouse gases (e.g., carbon dioxide and methane) into the atmosphere causes further warming and more carbon emissions.
To help understand the cycle, scientists need to carefully examine the potential for these carbon stocks to speed global warming rates by measuring how much of the greenhouse gases are emitted from decomposing permafrost carbon. A team of researchers led by Julie Jastrow and Roser Matamala, EVS terrestrial ecologists, is contributing to that effort through an integrated set of research approaches.
Their work, recently published in Science Advances, focused on quantifying how much carbon is stored in permafrost-affected soils and, more specifically, where it is stored in the soil layers.
One important finding suggests that more carbon occurs closer to the surface — within a meter — than scientists previously believed, making more of the region's carbon vulnerable to thawing, decomposition and release as global air temperatures rise, potentially feeding the warming cycle.
“Overall, this new picture of how the vast amounts of organic carbon stored in permafrost-affected soils are distributed across much of the world's coldest land areas will help to improve the ability of Earth system models to predict the impact of rising global temperatures on future emissions of greenhouse gases from these rapidly changing regions,” said Jastrow.
Read the full article by Mary Fitzpatrick.