Justices Skeptical in Emissions Case

A six-state lawsuit seeking to cap greenhouse gas emissions from power plants nationwide seemed likely to fail Tuesday, after Supreme Court justices suggested that recent federal action to slow climate change left no room for separate litigation.

The states sued five major power companies, alleging that by discharging 650 million tons of carbon dioxide annually, they accelerated global warming and caused damage such as smog in L.A. and lower crop yields in Iowa.

Connecticut, California, Iowa, New York, Rhode Island, Vermont and New York City pinned their case on a 1907 precedent allowing states to protect against pollution.

When the case was filed in 2004, the Bush administration maintained that carbon dioxide wasn't a pollutant and said the EPA lacked authority to regulate it.

In a 2007 case brought by some of the same states, the Supreme Court ruled that carbon dioxide met the Clean Air Act's definition for air pollution and fell within EPA authority. Under the Obama administration, the EPA has proposed new regulations to settle separate lawsuits filed by states, cities and environmental groups.

The states acknowledge that the EPA's proposed regulations, if implemented, would supersede their lawsuit.

Nonetheless, several justices signaled that the current state of the EPA regulatory process was enough to quash the states' lawsuit.

The Obama administration has sided with the power companies, asserting that its own efforts to rein in greenhouse gasses are legally sufficient.

Both the power companies and the administration contend that greenhouse gases are too complicated a problem to be resolved by courts.

"The very name of the alleged nuisance, 'global warming,' itself tells you much of what you need to know," acting Solicitor General Neal Katyal told the court. "There are billions of emitters of greenhouse gases on the planet and billions of potential victims as well."