Hydropower’s Downside

Sometimes you can’t seem to win. Hydropower, which seems one of the greener power sources, is now reported to have negative repercussions as far as greenhouse gases are concerned. This article from New Scientist magazine claims that “hydroelectric power can seriously damage the climate. In some cases, the article claims, dams produce more greenhouse gases per unit of power generated than does a fossil fuel-powered plant.

The reason? The carbon tied up in trees and plants in a dammed lake’s footprint rot and release their CO2; and plant matter that decomposes without oxygen results in a build-up of dissolved methane, which is released when the water goes through the dam’s turbine.

Essentially, the article says, man-made reservoirs convert carbon dioxide in the at
mosphere into methane, which is a much more potent greenhouse gas. And there is enough of this going on that countries ought to include it in their carbon budgets.