A Court Rules for the Planet A federal court decision on Tuesday upholding the Environmental Protection Agency's landmark rulings to control greenhouse gases was a decisive victory for the Obama administration and a devastating blow to polluters. It vindicated the administration's strategy of controlling emissions through regulation and showed good sense at a time when both the agency and the science of global warming are under relentless Congressional attack. The unanimous decision by a three-judge panel of the United States Court of Appeals for the District of Columbia covered dozens of suits from industry groups and 14 states challenging four rules that are components of the administration's effort to limit greenhouse gases. The most important of these - the bedrock from which the other rules flowed - was the agency's "endangerment finding" in 2009 that carbon dioxide and other greenhouse gas emissions constitute a danger to public health and could thus be regulated under the Clean Air Act. The judges said the agency's reading of its authority had been "unambiguously correct" and that the agency had based its case on careful research and sound science. The court upheld three related regulations, including the first round of clean car and fuel economy standards covering model years 2012-16, issued by the E.P.A. and the Transportation Department in 2009 and aimed at significantly reducing greenhouse gases from cars and light trucks while improving fuel efficiency. It also upheld rules establishing a timetable for controlling emissions from stationary sources like power plants and "tailoring" those controls so that only the largest emitters are covered. President Obama had hoped that Congress would tackle greenhouse gases through legislation. When that did not happen, the administration had to use its authority under the clean air laws. With that power firmly ratified, the E.P.A. can now move ahead with the second round of clean car standards proposed last year and a final rule on power plants. Both will be good news for the planet.