WASHINGTON, D.C. --- The Supreme Court today rejected the Bush administration's policy of refusing to regulate greenhouse-gas emissions. In a 5-4 decision, the court ruled that greenhouse gases were air pollutants subject to regulation under the Clean Air Act, according to a news report on the Los Angeles Times Web site. The justices said the Environmental Protection Agency didn't comply with the Clean Air Act in 2003 when it decided against ordering cuts in carbon emissions from new cars and trucks. Twelve states, including California and Massachusetts, are trying to force the EPA to limit emissions from new cars and trucks. The decision also boosts state efforts to enact their own regulations on greenhouse-gas emissions, according to a news update on Bloomberg.com. The Clean Air Act, enacted in the 1970s, requires that the EPA regulate any air pollutant that's likely to endanger public health or welfare. Today's decision, written by Justice John Paul Stevens for the five-justice majority, specifically rejected the Bush administration's "laundry list of reasons not to regulate." Stevens' opinion was joined by Justices Anthony M. Kennedy, David H. Souter, Ruth Bader Ginsburg and Stephen G. Breyer. Chief Justice John G. Roberts Jr. dissented, along with Justices Antonin Scalia, Clarence Thomas and Samuel A. Alito Jr.