The U.S. Supreme court rejected a lawsuit by California and seven other states seeking to curb greenhouse gases emitted from coal-fired plants owned by five major utilities. The court basically found California\u2019s legal effort duplicative and preempted by federal regulatory carbon curbs under development. The states\u2019 effort to cap the 650 million tons of carbon dioxide produced annually by the coal plants of American Electric Power, the Tennessee Valley Authority, and three other larger polluting utilities under federal nuisance law was preempted by U.S. Environmental Protection Agency authority, ruled the high court 8-0. Whether the carbon dioxide emissions--amounting to 25 percent of the power industry\u2019s annual carbon emissions--constitute a nuisance under state law, however, is to be decided upon remand. The federal Clean Air Act \u201cprovides a means to seek limits on emissions of carbon dioxide from domestic power plants--the same relief the plaintiffs seek by invoking federal common law. We see no room for a parallel track,\u201d Justice Ruth Ginsberg wrote June 20. Much to the consternation of environmentalists, the Obama Administration sided with utilities. Justice Sonia Sotomeyer recused herself. She sat on the federal appeals court that allowed the states and City of New York\u2019s legal challenge to go forward. The earlier ruling by the Second District Court of Appeals in New York in September 2009 found that complaints by California, seven other states, and three land trusts, filed in July 2004 against AEP and other generators with plants in 20 states were not exclusive political matters and were properly before the court. In another Supreme Court ruling, EPA v. Massachusetts, EPA was given the authority to regulate greenhouse gases to protect public health. The high court noted in this week\u2019s decision that the agency is developing regulations to curb carbon emissions from coal plants, many of which are in the East. EPA is \u201cbest suited to serve as primary regulator of greenhouse gas emissions,\u201d noted the Supreme Court\u2019s ruling. The EPA declined to comment, saying the US Department of Justice was handling the matter. \u201cWe are reviewing the Court\u2019s ruling. We have no further comment,\u201d DOJ spokesperson Wyn Hornbuckle wrote in an email. The other states involved include Connecticut, Iowa, New Jersey, New York, Rhode Island, Vermont, and Wisconsin. The other defendants include Southern Co., Xcel Energy Inc., and Duke Energy Corp. The case is American Electric Power Co. v. Connecticut, 10-174.