The EPA has just announced its final rule for greenhouse gas emissions from large fixed sources such as power plants and refineries. Starting in January of next year large facilities already required to obtain Clean Air Act permits for other emissions will have to seek a greenhouse gas permit if such admissions increase by 75,000 tons/yr or more. Six months later the requirements will expand to cover all new facilities with emissions of at least 100,000 tons/yr and older installations with modifications that result in increases of 75,000 tons/yr or more. The rule covers not only CO2 but also methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. It's anticipated that the rules will be expanded to additional sources effective July 2013.
The EPA believes that these new standards will avoid overwhelming permitting burdens that otherwise would have fallen on the government and most sources of greenhouse gas. The EPA notes that without this rule the permitting and "best available control technology" burdens would fall on operations with emissions as low as 100 tons/yr producing "an absurd result" - not to mention an immense political backlash propelled by an impossible to administer regulatory scheme. Instead, conceding in essence the slippery slope objection, expansion of the regulations to smaller emitters will proceed "one-step-at-a-time". Had the rules become effective for all emitters at once an estimated 6 million U.S. farms and businesses would have suddenly become subject to the permitting process with the time from application to permit approval lengthening to a decade or more.
The CliffsNotes version is here: Fact Sheet and here's the Final Rule