Global Warming Case To High Court

On Nov. 29, the Supreme Court heard oral arguments in the first case on global warming ever to come before the justices. In Massachusetts v. EPA, the court must decide whether EPA has authority under the Clean Air Act to regulate greenhouse gases—carbon dioxide chief among them—from new cars and trucks.

The case was brought by 12 states and four jurisdictions and is led by Massachusetts. Massachusetts Assistant Attorney General James R. Milkey urged the Court to force EPA to revisit its 2003 decision not to regulate CO₂ and other greenhouse gases from new vehicles. The Clean Air Act, he pointed out, says EPA "shall" set standards for any air pollutant that "may reasonably be anticipated to endanger public health or welfare." The law also states that welfare includes effects on climate and weather.

The justices spent much of the time at the hearing discussing whether Massachusetts and the 11 other states have standing under the Constitution to challenge EPA's decision not to regulate greenhouse gas emissions from vehicles. Milkey pointed out that Massachusetts would lose 200 miles of coastline to rising seas if CO₂ emissions are not reduced. He said the state "would be hit particularly hard because we're also subject to land subsidence."

Justice Antonin Scalia noted that constitutional standing requires imminent harm and asked whether the harm is imminent. Milkey responded that sea-level rise is already occurring from the current amount of greenhouse gases in the air and that situation will get worse as concentrations rise. He also pointed out that "New York State could well lose thousands of acres of its sovereign territory by the year 2020" if emissions are not reduced. Overall, on the basis of the questions they asked, the justices' views about this case during the hearing seemed fairly evenly divided.

The Supreme Court ruling will affect existing or future laws in the 12 suing states, which want to limit CO₂ emissions from new cars and trucks in the absence of EPA action. What's more, if the Court sides with the states, it will open the door for other jurisdictions to follow suit and begin regulating those emissions.

A decision is expected in July 2007.