Lets get everyone up to speed with events on regulation of greenhouse gases (GHGs) including CO2:
1. Supreme Court says CO2 is a pollutant under the Clean Air Act. In Massachusetts v. EPA decided in April of 2007, the Supreme Court held that GHGs are pollutants that may be regulated under the Clean Air Act. But

For the first time a court has revoked a permit due to concerns over C02 emissions and climate change. While there have been previous instances where states have denied permits due to concerns with C02 emissions, this is the first time a court has revoked a previously issued permit. Notably, the Court did not base its decision on state law, rather it ruled the Clean Air Act (CAA) requires analysis and control of C02 emissions.