The Bay of Bengal is acting as an unexpected weapon against global warming according to a new study published in the science journal nature. The study conducted by a team of researchers led by Valier Galy of France’s Nancy University found that around 70 to 85% of terrestrial carbon swept down by the Ganga-Brahmaputra systems from the Himalayas settles to the sea floor rather than escape to the atmosphere.
The high rate of erosion in the Himalayas causes high rates of sedimentation in the Sunderban delta. Approximately two billion tones of sediments are transported from the Himalayas to the Bengal coast every year. As a result, the thick and fast growing sediments are not exposed much to oxygen and this starves the microbes of the fuel needed to degrade the organic matter and emit the carbon dioxide and methane. Eventually the powerful ocean currents transfer the sediments to deep sea floor where they are safely stored for millions of years. The process is known as ‘sink’, which is a natural phenomenon by which greenhouse gas is stored instead of being released to the atmosphere. According to Galy’s estimate, Bengal basin stores about 10 to 20% of total terrestrial carbon stored on the ocean bed.
The findings in the Bengal delta is totally unlike what has been found in other major river deltas the world over, including the Amazon where 70% of organic carbon return to the atmosphere as carbon dioxide gas, adding to greenhouse gases in the atmosphere.