The Supreme Court issued its decision on whether the EPA can and should regulate greenhouse gas emissions as pollutants. The court ruled against the administration and asked the EPA to reconsider its opposition to regulating carbon dioxide.
Update: See Gristmill's take: What does the Massachusetts case mean?
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.
"EPA has offered no reasoned explanation for its refusal to decide whether greenhouse gases cause or contribute to climate change," Stevens said. He was joined by his liberal colleagues, Justices Stephen Breyer, Ruth Bader Ginsburg and David Souter, and the court's swing voter, Justice Anthony Kennedy.