Researchers at the National Sun Yat-sen University and the National Central University in Taiwan claim hydropower causes more global warming than coal or oil-fired power stations. Explaining his three-year study of rivers, lakes and reservoirs across south-east Asia, Professor Chen Chen-tong said a hydropower dam inadvertently produces methane and nitrous oxide, chemicals that have an adverse effect on eco-systems. ‘

One tonne of methane equals 21 tonnes of carbon dioxide and one tonne of nitrous oxide equals 200 tonnes of carbon dioxide,’ he said. The academic said China’s Three Gorges Dam will produce serious environmental effects as the dam blocks three-quarters of the organic matter that should flow from downstream.

The world’s largest dam began operation on May 20th. The Bihai and Shibao hydropower projects are due to come online next year and 2009 respectively. Read the full story: Clean hydropower a myth warns study