Dams ‘contributing to global warming’

The world’s dams are contributing millions of tonnes of harmful greenhouse gases and spurring on global warming, according to a US environmental agency.

International Rivers Network executive director Patrick McCully told Brisbane’s Riversymposium rotting vegetation and fish found in dams produced surprising amounts of methane – 25 times stronger than carbon dioxide.

‘Often it’s accepted that hydropower is a climate friendly technology but in fact probably all reservoirs around the world emit greenhouse gases and some of them, especially some of the ones in the tropics, emit very high quantities of greenhouse gases even comparable to, in some cases even much worse than, fossil fuels like coal and gas,’ Mr McCully said.

He said when water flow was stopped, vegetation and soil in the flooded area and from upstream was left to rot, as well as fish and other animals which died in the dam.

They then released carbon dioxide, methane and nitrous oxide into the air.”