Greenhouse gases are air pollutants under the Clean Air Act: U.S. policy on global warming today

Monday, 02 April 2007

The Supreme Court ordered the federal government today to take a fresh look at regulating carbon dioxide emissions from cars. In a 5-4 decision, the court said the Clean Air Act gives the Environmental Protection Agency the authority to regulate the emissions of carbon dioxide and other greenhouse gases from cars. Greenhouse gases are air pollutants under the landmark environmental law, Justice John Paul Stevens said in his majority opinion. The case is Massachusetts v. EPA, 05-1120. Greenhouse gases, flowing into the atmosphere and oceans at an unprecedented rate, are leading to larger extreme climatic events, rising sea levels and other marked ecological changes. The politics of global warming have changed dramatically since the court agreed last year to hear its first global warming case. Business leaders are saying they are increasingly open to congressional action to reduce greenhouse gases emissions, of which carbon dioxide is the largest. Carbon dioxide is produced when fossil fuels such as oil and natural gas are burned. The court had three questions before it. Do states have the right to sue the EPA to challenge its decision? Does the Clean Air Act give EPA the authority to regulate tailpipe emissions of greenhouse gases? Does EPA have the discretion not to regulate those emissions? The court said yes to the first two questions. On the third, it ordered EPA to re-evaluate its contention it has the discretion not to regulate tailpipe emissions. The court said the agency has so far provided a "laundry list" of reasons that include foreign policy considerations. The majority said the agency must tie its rationale more closely to the Clean Air Act. The decision also is expected to boost California's prospects for gaining EPA approval of its own program to limit tailpipe emissions of greenhouse gases. Federal law considers the state a laboratory on environmental issues and gives California the right to seek approval of standards that are stricter than national norms.