Research Indicates Large Dams Contribute Greenhouse Gases
Hydropower reservoirs are considered to be major sources of low-carbon electricity that can be used to cut greenhouse gas emissions to combat climate change. But those same reservoirs emit global warming gases, and a team of researchers has now tallied just how much those gases impact the climate.
Globally, reservoirs are responsible for about 1.3 percent of the world’s man-made greenhouse gas emissions each year, or about the same as Canada’s total emissions, according to a study to be published in the journal Bioscience. The findings come from a team of researchers led by Washington State University-Vancouver and the Environmental Protection Agency.
That emissions estimate may not sound like much, but the study says reservoir emissions can contribute significantly to carbon budgets countries use to meet their climate goals. Reservoirs emit mostly methane, a greenhouse gas about 35 times as potent as carbon dioxide in its potential to warm the atmosphere over the course of a century.

Ray Morris