A study in the May 6th issue of Nature indicates the increase in rainfall forecast by global climate models is likely to hasten the release of carbon dioxide from tropical soils, further intensifying global warming by adding to human emissions of this greenhouse gas into Earth’s atmosphere.

Based on analysis of sediments cored from the submarine delta of the Ganges and Brahmaputra rivers, the study was conducted by an international team led by Dr. Christopher Hein of William & Mary’s Virginia Institute of Marine Science. Collaborators include Drs. Valier Galy of the Woods Hole Oceanographic Institution, Muhammed Usman of the University of Toronto, and Timothy Eglinton and Negar Haghipour of the Swiss Federal Institute of Technology in Zurich (ETH Zurich). Major funding was provided by the U.S. National Science Foundation.

“We found that shifts toward a warmer and wetter climate in the drainage basin of the Ganges and Brahmaputra rivers over the last 18,000 years enhanced rates of soil respiration and decreased stocks of soil carbon,” says Hein. “This has direct implications for Earth’s future, as climate change is likely to increase rainfall in tropical regions, further accelerating respiration of soil carbon, and adding even more CO2 to the atmosphere than that directly added by humans.”

Read more at Virginia Institute of Marine Science