//The biggest impact comes from methane, a gas that has 34 times the global warming impact as carbon dioxide.
When acres of land are flooded to build a reservoir, the trees and plants that end up underwater can start to break down and release methane. Fertilizers like nitrogen and phosphorus, flowing into dams from farms and waste, can make algae quickly grow—another source of methane as it breaks down…
//
from Facebook http://ift.tt/2ds1LBH