Supreme Court will hear challenge to EPA caps on factory emissions

The Supreme Court agreed Tuesday to decide whether to block key aspects of the Obama administration's plan aimed at cutting power plant and factory emissions of the gases blamed for global warming.

The justices said they will review a unanimous federal appeals court ruling that upheld the government's unprecedented regulation of six heat-trapping gases.

The question in the case is whether the Environmental Protection Agency's authority to regulate automobile emissions of greenhouses gases as air pollutants, which stemmed from a 2007 Supreme Court ruling, also applies to power plants and factories.

The case will be argued in early 2014.

The administration's climate change plans hinge on the 2007 decision in Massachusetts v. EPA which said that EPA has the authority under the Clean Air Act to limit emissions of greenhouse gases from vehicles.

Two years later, Obama's EPA concluded that the release of the six gases endangered human health and welfare, a finding the administration has used to extend its authority beyond automobiles to large stationary sources. The president gave the EPA until next summer to propose regulations for existing power plants, the largest unregulated source of global warming pollution.

The justices declined to take up even larger questions posed by some of the appeals, including whether the 2007 decision in Massachusetts v. EPA should be overturned.

The regulations have been in the works since 2011 and stem from the landmark Clean Air Act that was passed by Congress and signed by President Richard Nixon in 1970 to control air pollution.

The administration has come under fierce criticism from Republicans for pushing ahead with the regulations after Congress failed to pass climate legislation, and after the Bush administration resisted such steps.

In 2012, a three-judge panel of the U.S. Circuit Court of Appeals for the District of Columbia concluded that the EPA was "unambiguously correct" in using existing federal law to address global warming.

The judges on that panel were: Then-Chief Judge David Sentelle, who was appointed by Republican President Ronald Reagan, and David Tatel and Judith Rogers, both appointed by Democrat Bill Clinton.

The Associated Press