This could have a significant impact on global water and energy security. Dam capacity is expected to drop from 6 trillion cubic meters to 4.655 trillion cubic meters by 2050. The study, which looked at data from more than 47,000 dams in 150 countries, found that 16% of the original capacity had already been lost.
Dam Losses by Country
The United Nations study also highlighted the potential losses different countries could face. The United States is facing losses of 34% by 2050, with Brazil estimated to lose 23%, India 26%, and China 20%. Critics have long warned that giant dams' long-term social and environmental costs far outweigh their benefits.
Alternatives to Dams
Vladimir Smakhtin, director of the UN University's Institute for Water, Environment and Health and one of the study's authors, said that dam building worldwide had already declined significantly. He suggests that instead of building more dams, alternative solutions for generating power should be considered. "I would argue that we should now be asking what the alternatives to dams - including in generating power - considering that they are being phased out are," he said.