Massachusetts and the federal government squared off Nov. 29 at the U.S. Supreme Court over federal regulation of greenhouse gases. In oral arguments at the court in the case, "Massachusetts v. Environmental Protection Agency," both sides faced pointed questions from the justices, generally reflecting the split on the court between conservatives and moderates. A decision is expected before the court ends its term next summer and will provide a clearer picture of the court's views on environmental issues.
The case deals with a 2003 EPA determination that the Clean Air Act didn't give it the authority to regulate vehicles' emissions of carbon dioxide and other greenhouse gases to deal with global climate change. Massachusetts contends that the statute does give EPA that power. Last year, a federal appeals court ruled in EPA's favor, and the state appealed to the Supreme Court.