Amazon deforestation may undercut South American hydropower projects

The lush tropical forests that are currently found along the Xingu river.

University of Texas

The deforestation of the Amazon is often referred to in terms of the loss of habitat and species. But it also may come back to cause unforeseen problems for us humans, based on a new study in PNAS. Most models of future hydropower productivity have assumed deforestation will lead to increased water runoff, which will in turn increase the amount of power that existing projects will generate. But the study suggests that the feedback between forests and rainfall will ultimately lead to a prolonged and more intense dry season, leaving hydroelectric plants generating less power.

Hydropower is a major contributor of renewable electricity in South America. 100 percent of Paraguay's electricity comes from hydro, and it's a major exporter of power. Brazil isn't far behind, meeting 80 percent of its electrical needs using hydropower, and several major projects are still in the works.

The study focuses on one of these projects, which will tap into the potential of the Xingu river basin. A series of damns and hydroelectric facilities in the basin are slated to fill 40 percent of the increase in generating capacity that Brazil expects to need by the end of the decade.