New global warming culprit: Methane emissions jump dramatically during dam drawdowns

Scientists have discovered a surprising new chemical compound in Earth’s atmosphere that reacts with sulfur dioxide to form sulfuric acid, which is known to have significant impacts on climate and health. The new compound, a type of carbonyl oxide, is formed from the reaction of ozone with alkenes, which are a family of hydrocarbons with both natural and human-made sources.

Researchers have documented an underappreciated suite of players in global warming: dams, the water reservoirs behind them, and surges of greenhouse gases as water levels go up and down. In separate studies, researchers saw methane levels jump 20- and 36-fold during drawdowns.