Jolting Congress into action on greenhouse gases

AS SOON as next week, the Environmental Protection Agency could follow through on an order from the Supreme Court to either declare carbon dioxide a pollutant or to say why it isn't. That decision could usefully signal to the world that the United States is serious about regulating greenhouse gas emissions. But it should also send a shiver down Congress's collective spine. Because the regulation of carbon will have a profound effect on the American economy, this vital task should be the responsibility of Congress, not of unelected officials at the EPA.

The EPA does have the authority under the Clean Air Act to regulate air pollutants that have "effects on [public] welfare," "on . . . weather, . . . and climate, . . . as well as effects on . . . personal comfort and well-being." Emitted greenhouse gases, particularly carbon dioxide, will have such effects. The Supreme Court's 2007 ruling in Massachusetts v. EPA affirmed this when the majority concluded that the EPA had the authority to control emissions from motor vehicle tailpipes and ordered the agency to issue an endangerment finding. Then-EPA Administrator Stephen L. Johnson was close to doing so on the basis of public welfare, but he opted for another public comment period after intense pressure from the Bush administration.

The probable and impending endangerment finding by current EPA Administrator Lisa P. Jackson would fulfill the court's mandate and then require Ms. Jackson to devise regulations for the transportation sector. But having declared greenhouse gases a pollutant, the agency would have to set about the long process of regulating such gases from all other sources as well. The U.S. Chamber of Commerce expresses concern about the impact of such regulation on the construction industry, because residential and commercial buildings are larger sources of global-warming pollution than are motor vehicles. Rep. John D. Dingell (D-Mich.), then-chairman of the House Energy and Commerce Committee, predicted last year that seeking to control climate change with such piecemeal regulation would lead to a "glorious mess."

The best way to stop this from happening is for Congress to adopt a more rational scheme, by putting a price on carbon with a tax (ideally) or a cap-and-trade market. Next week, Rep. Henry A. Waxman (D-Calif.), the current chairman of the Energy and Commerce Committee, will hold hearings on the discussion draft of comprehensive energy legislation that he and Rep. Edward J. Markey (D-Mass.), chairman of the energy and environment subcommittee, released before the Easter recess. While the proposal details many ambitious programs for renewable energy and efficiency, it is noticeably mute on the contours of a cap-and-trade system. Specifically, it doesn't say whether the pollution allowances would be auctioned or a portion given away to industry to ease the transition to a carbon-constrained economy. This is an important question, one whose answer will have a profound impact on the way Americans live -- one of many basic issues that should be settled by their representatives in Congress.