US EPA Declares Greenhouse Gases a Threat to Public Health and Welfare. (April 20, 2009)

In April 2007 the US Supreme Court ruled that carbon dioxide is a pollutant under the Clean Air Act, and it remained only for the federal Environmental Protection Agency (EPA) to rule that carbon dioxide having been deemed a pollutant, also represented a threat.

Last week the EPA declared greenhouse gases a threat to public health and welfare, a move that gives the Obama administration broad powers to regulate greenhouse gases without going through Congress should it choose to do so. It remains, however, for the EPA's document to go through a 60-day public comment period.

NatureNews reports: "[T]he EPA included in its endangerment finding not only carbon dioxide but also methane, nitrous oxide, sulphur hexafluoride, hydrofluorocarbons and perfluorocarbons — all of the greenhouse gases covered under the United Nations climate treaty. The document specifically cited greenhouse gas emissions from vehicles as a danger to public health."

Overall legal opinion would prefer to see a law passed by Congress because it would be less likely to face legal challenges, and while administration officials would prefer to work with lawmakers on climate legislation the President would be prepared to implement direct regulation if Congress failed to act.