Last week, a landmark ruling by the Environmental Protection Agency (EPA) strengthened the hand of supporters of a climate change bill in the U.S. In it the EPA formally declared that carbon dioxide emissions present a danger to public health. This after the 2007 US Supreme Court decision in Massachusetts v. EPA in which the court held that the EPA had the authority to regulated GHGs under the Clean Air Act. Now over the next 60 days, the EPA can use the Act to impose limits on heavy polluters of carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride. This is important because if U.S. proposals for a cap-and-trade scheme fall through in Congress — possible considering the staunch political opposition to the initiative — it will still be possible to impose wide-ranging carbon regulations on on carbon-intensive industries.