
A dry section of the Guavio Reservoir that feeds the Guavio Hydroelectric Power Plant in Gachala, Colombia, in April. Jhojan Hilarion/Agence France-Presse — Getty Images
We knew that dams’ days are numbered, but the evidence keeps mounting:
The struggle of the world’s largest source of renewable last year could have important implications for the fight against climate change.
Global pollution from electricity generation was set to fall last year, thanks to the growth of renewable energy. Then came the droughts.
Hydropower, the biggest source of renewable energy in the world, was crippled by lack of rain in several countries last year, driving up emissions as countries turned to fossil fuels to fill the gap. Continue reading


























