The justices unanimously overturned a ruling by a U.S. appeals court that the lawsuit now involving six states can proceed in an effort to force the coal-burning plants to cut emissions of gases that contribute to climate change.
In a defeat for environmentalists, the Supreme Court agreed with the companies that regulating greenhouse gases should be left to the Environmental Protection Agency (EPA) under the clean air laws.
The ruling stemmed from a 2004 lawsuit claiming the five electric utilities have created a public nuisance by contributing to climate change. The lawsuit wanted a federal judge to order them to cut their carbon dioxide emissions.
Lawyers for the power companies, including an Obama administration attorney representing the government-owned Tennessee Valley Authority (TVA), said the scope of the lawsuit was unprecedented, involving national and international issues outside the power of federal judges.
The utilities -- American Electric Power Co Inc, Southern Co, Xcel Energy Inc and Duke Energy Corp, along with TVA -- account for about 10 percent of U.S. carbon dioxide emissions.