How do dams contribute towards reducing CO2 emission?
Answers
Dams don't reduce CO2 emissions. Instead, when a river is blocked, water gathers behind the dam, creating an unnatural, stagnant lake that often kills off a lot of the existing ecosystem. The excess water is pushed onto the banks, which are often covered in plant life. These plants are then smothered and die. Bacteria in the water then decompose these plants, generating carbon dioxide and methane—a greenhouse gas 86 times more potent than CO2.
These gases bubble up to the surface of the reservoir and are released into the atmosphere.
Even more of these gases are produced if the upstream river water contains extra nitrogen or phosphorus as a result of fertilizer runoff. These nutrients allow naturally-occurring algae in the river to flourish, but then quickly overwhelm the water’s oxygen resources. As the algae dies, it’s broken down like other organic matter, creating even more of these gases.
Dams don't decrease CO2 discharges. Alternatively, when a river is obstructed, excess water accumulates due to which it creates an incredible, filthy pond that frequently kills a lot of the existent species of the ecosystem. The excess water is exerted toward the banks, which are often incorporated in plant life. These plants are then extinguished and disappear. Bacteria in the water then disintegrate the plant's life, producing CO2 and methane a greenhouse gas which is several times more persuasive than carbon dioxide.