Dams cause climate change

More and more scientific research shows that reservoirs, especially in the tropics, are a significant source of global greenhouse gas pollution.

Brazilian researchers estimate that in 2007, methane gas from reservoirs and dams is responsible for 4% of human-induced climate change.

The main factors affecting home gas emissions
glass of dams (Graphics: International Rivers)

Greenhouse gases, mainly methane (CH ₄ ) and carbon dioxide (CO ₂ ), are released from all several dozen reservoirs surveyed. Gas escapes from the reservoir surface, turbines, spillways and dozens of kilometers downstream. Maximum emissions in hot climates. Large-scale hydroelectric plants in the tropics can impact the global warming at a much greater level than fossil-powered plants with the same power output.

'Fuel' for these emissions is rotting, decomposing organic matter in plants and land is submerged when the reservoir is first filled with water. Carbon in plankton and plants that live and die in reservoirs, debris (sand, gravel .) is washed away from the upper water source and seasonal flooding in the area around the reservoir causes gas emission greenhouses are continuous, as long as the reservoir exists.

The role of reservoirs as a pollutant, climate change impact attracts increasing attention of policy communities as well as climate science.