What is the contribution of dams to global warming?
According to the most detailed estimate available, done by Ivan Lima and colleagues from Brazil’s National Institute for Space Research (INPE), the world’s large dams emit 104 million metric tonnes of methane annually from reservoir surfaces, turbines, spillways and rivers downstream (1). This implies that dam methane emissions are responsible for at least 4% of the total warming impact of human activities. No one has yet calculated the total climate impact of dams, which would include releases of carbon dioxide and nitrous oxide.
