Dams May Contribute to Greenhouse Gas Levels

Washington State University research shows more methane bubbles out of water as it is drawn down.

Washington State Univ. 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.

Bridget Deemer, a doctoral student at Washington State Univ.-Vancouver, measured dissolved gases in the water column of Lacamas Lake in Clark County and found methane emissions jumped 20-fold when the water level was drawn down. A fellow WSU-Vancouver student, Maria Glavin, sampled bubbles rising from the lake mud and measured a 36-fold increase in methane during a drawdown.