Buried carbon may pose climate risk

AFP-JIJI

Stocks of organic carbon buried deep underground could fuel global warming if disturbed by erosion, farming, deforestation, mining or road-building, a study said Sunday.

Scientists from the United States and Germany discovered one such reserve in Nebraska comprising vast quantities of burned vegetation up to 6.5 meters (21 feet) below the surface.

“We found almost comparable amounts of carbon stored in this deep soil layer than we would in the top one meter of soil under a grassland vegetation,” said study co-author Erika Marin-Spiotta of the University of Wisconsin, Madison.

“We are potentially grossly underestimating how much carbon is stored below ground in our global inventories,” the study said.

Such ancient fossil soils are found worldwide beneath deposits such as river sediments and volcano debris.

“Only recently have scientists become more concerned about deep soil carbon, as we are finding it is more reactive than we ever imagined,” said Marin-Spiotta.