This post is by Tom Olson, a consulting attorney for the Climate and Air Campaign at Environmental Defense Fund.

Last Friday, the U.S. Environmental Protection Agency (EPA) finally released its Advance Notice of Proposed Rulemaking - EPA's answer to a 2007 Supreme Court ruling that greenhouse gases fall within the Clean Air Act's definition of "pollutant".

There are a number of differences between the final document and the leaked May 30th draft. (See this post from a Georgetown Law professor praising the draft's balance and expertise.) Most significantly, EPA chief Stephen Johnson prefaced the document with a series of denunciations by White House officials. And then, adopting the views of the White House, he disparaged the work of his own staff.

The final version also included some disturbing changes to the analysis itself.

For example, to minimize the benefits of addressing global warming under existing law, the final version assumes that gasoline prices will average just over $2 per gallon from 2008 to 2030 - clearly absurd. Moreover, it ignores the benefits of addressing global warming (wisely included in the draft). As a result, the final version estimates the net benefit of regulating greenhouse gas emissions from cars and light trucks over the next three decades to be only up to $830 billion, versus the $2 trillion estimated in the draft.

Even the leaked May draft is watered down from a draft that EPA sent to the White House in December. Sent in an email message that the White House refused to open, the December draft concluded that greenhouse gases are dangerous pollutants that must be controlled. The May draft and the final version released on Friday leave this as an open question.

A senior EPA official told the New York Times that the December and May drafts "showed that the Clean Air Act can work for certain sectors of the economy to reduce greenhouse gases. That's not what the administration wants to show. They want to show that the Clean Air Act can't work." That's certainly the case. Johnson wrote in his preamble:

I believe the ANPR demonstrates the Clean Air Act, an outdated law originally enacted to control regional pollutants that cause direct health effects, is ill-suited for the task of regulating global greenhouse gases.

The bottom line is that Johnson and the White House ignored the scientific imperative to act, and defied the Supreme Court edict that they do so. With the required 120 days for comments after stalling for so long, there is no way that EPA could put out new regulations before the end of the Bush presidency.

On the plus side, EPA staff have a head start in getting the ball rolling in a new administration.