River Basins Can Hold Carbon for 17,000 Years, Study Says

Researchers say the soils and sediments of the Ganges-Brahmaputra basin are able to store carbon for thousands of years, a fact they warn could portend increased rates of carbon dioxide emissions as such vulnerable regions are exposed to the effects of climate change. Using radiocarbon dating, scientists at the Woods Hole Oceanographic Institution (WHOI) found that organic carbon can remain for 500 to 17,000 years, despite extraordinarily high rates of physical erosion and sediment transport within the basin that drains the Himalayas. Downstream, within the Gangetic floodplain, the carbon resides from 1,500 to 3,500 years. The longer the carbon remains within the soil, the longer it is kept out of the atmosphere, said Valier Galy, a WHOI researcher and one of the authors of the study published in Nature Geoscience. But as rising temperatures destabilize soils and “ancient” carbon stored within the Ganges basin and elsewhere in the world, this could lead to more carbon dioxide being emitted into the atmosphere, hastening warming.