| Hydro's Methane Bomb | 17 October 15 |
The principal environmental risk of hydroelectric dams is organic material—vegetation, sediment and soil—that flows from rivers into reservoirs and decomposes, emitting methane and carbon dioxide into the water and the air. Recent research identified increased risks from methane emissions. Organic material—vegetation, sediment and soil—flows from rivers into reservoirs and decomposes emitting methane and carbon dioxide into the water and then the air throughout the hydro-electric generation cycle. Studies indicate that where organic material is the highest, hydro-electric dams can actually emit more greenhouse gases than coal-fired power plants. Large dams contain enormous amounts of cement, which during the construction process uses massive amounts of energy that emits greenhouse gas emissions. A 2011 study published in the science journal Science found that the "ability of terrestrial ecosystems to act as carbon sinks," could be one quarter less than previously thought. Clearly, carbon and methane emissions from hydro dams is a concern - particularly with so many mega-dams being constructed around the world. More study is needed to determine full carbon and methane emissions from hydro dams and spillways in order to properly include them in climate change discussions.
View October 6, 2015 EcoWatch article |
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