Climate change before the US Supreme Court

Following on yesterday’s post about the possibility for action on climate change in the US:

The US Supreme Court began hearing arguments today in a case about whether the EPA is required to regulate CO2 emissions under the Clean Air Act (see yesterday’s strong NY Times editorial). The suit was filed by a bunch of states and environmental organizations after the Bush Administration chose not to enforce any CO2 regulations.

From my understanding of the case, the court could effectively decide one of four ways.
i) The EPA must regulate CO2 under the Clean Air Act (because of the potential deleterious impacts of climate change)
ii) The EPA has the option to regulate CO2 under the Clean Air Act
iii) CO2 does not fall under the Clean Air Act but could be regulated otherwise
iv) The EPA does not have jurisdiction to regulate CO2, as there is not sufficient evidence to support the need for CO2 emissions controls.

The unlikely Door #1 would radically alter the status of emissions control in the US. It’s most likely the court decision, expected in the spring, will be along the lines of Door #3. Though that would technically be a losing verdict, it would strongly advance the argument for emissions policy.

There’s one thing that makes this case risky: the chance, albeit small, that the court meanders close to Door #4. This would not only make federal emissions controls unlikely, it could be used to argue against state policies or international agreements.