Large Methane Releases Could Swamp Arctic’s Ability to Absorb the Gas

A new study by two U.S. government research laboratories forecasts that vast amounts of methane frozen in Arctic Ocean sediments could be released into the marine environment and the atmosphere as the region warms. The study provides the most detailed description to date of how releases of methane, a potent greenhouse has, could both change the chemistry of the Arctic Ocean and pour into the atmosphere in large quantities. Conducted by scientists at the Lawrence Berkeley National Laboratory and the Los Alamos National Laboratory, the study describes a two-step process of methane release. In the first phase, methane clathrates — icy crystalline compounds on the sea floor that encase methane molecules — will break apart as the Arctic Ocean warms. In the second phase, large amounts of methane then seep into the Arctic Ocean and eventually overwhelm the natural ability of marine microbes to consume the gas, which is then released into the atmosphere. Computer simulations show that in some Arctic regions, such as the Bering Sea and Okhotsk Sea, so much methane could bubble into the ocean that oxygen levels will plummet and the sea will become acidified, rendering the ocean inhospitable for many organisms. “The amount of methane entering the ocean is huge and it changes the water chemistry dramatically,” said Matthew Reagan of the Berkeley lab.