New Scientist Breaking News - US Supreme Court to rule on climate change

The US Supreme Court decided on Monday to hear a case that will bring climate change and the regulation of carbon dioxide emissions before the court for the first time. The case could force the US Environmental Protection Agency (EPA) to regulate CO2 emissions from cars and other mobile sources.
"The [decision is] a big deal, because the Supreme Court rarely ever grants a review," says Richard Lazarus, professor of law at Georgetown University in Washington DC and co-counsel for the plaintiffs in the case.
The Supreme Court only agrees to hear about 1% of roughly 8000 petitions it receives each year. "It means that they think it's a very important issue and they need to review it now," he adds.
On trial
The case will put the evidence for climate change "on trial" (see Climate change: Let the Supreme Court decide) to determine whether the available data are enough to say that CO2 emissions pose a reasonable threat to the public's wellbeing.
The Clean Air Act mandates the EPA to regulate emissions from mobile sources that "cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare".
A later section of the law defines welfare to include weather and climate effects. Last year, a group of 12 US states and several non-profit environmental groups led by Massachusetts sued the EPA, claiming that this law obligates the EPA to regulate cars' CO2 emissions.
In July, the US Court of Appeals ruled against Massachusetts, which then appealed to the Supreme Court.
Regulate pollutants
The EPA and the US Department of Justice, which is representing the EPA in the case, could not be reached for comment because severe flooding in Washington DC forced their offices to close on Monday.
Gloria Bergquist, spokesperson for the Alliance of Automobile Manufacturers, a co-defendant in the case, notes that "nobody knows why the Supreme Court has chosen this case. It could be that the Supreme Court just wanted to clarify the issue or uphold the lower court's decision on different grounds."
If the court rules in favour of the plaintiffs, it could either force the EPA to regulate CO2 as a pollutant or merely compel it to reconsider the issue.
A ruling in the case is not expected until spring or summer 2007.