EPA announcement on greenhouse gas regulation - Q&A

The announcement of the EPA's proposed finding on 6 greenhouse gases has generated lots of buzz. In the Q&A below, I've tried to break it down and make sense of what exactly the EPA said and what that means.

What exactly did the EPA say?
The EPA said it proposed to find that the following 6 greenhouse gases in the atmosphere threaten the public health and welfare of current and future generations:

• Carbon dioxide (CO2)
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Hydrofluorocarbons (HFCs)
• Perfluorocarbons (PFCs)
• Sulfur hexafluoride (SF₆)

What does proposed to find mean?
It means unless someone or something changes the EPA's mind during the public comment period over the next 60 days, it will issue a final finding that will confirm what it is saying now.

And that will set some pretty serious wheels in motion.

Like what?
The EPA will then have to issue regulations limiting the amount of greenhouse gases that major sources, including automobiles and coal-fired power plants, can emit.

But the EPA and the White House prefer that limits on greenhouse gas emissions be achieved through climate-change legislation from Congress, rather than by regulations.

Why will the EPA have to issue regulations if Congress doesn't act?
Because in April 2007, the U.S. Supreme Court ruled that under the Clean Air Act, the EPA must regulate these gases if it found the gases caused or contributed to air pollution that endangered human health or welfare. After studying the science for 2 years, the EPA is proposing to find just that.

Will anyone change the EPA's mind in the next 60 days?
I don't know, but you can bet a lot of people are going to try hard. If you'd like to give it a shot, here are the instructions for submitting a comment in writing (pdf).

I lap this stuff up. Where can I find the full text of the proposed finding?
The official version will be published in the Federal Register and will be available in the Docket soon, under Docket ID No. [EPA-HQ-OAR-2009-0171].

If you can't wait -- and I suspect you can't -- click here (pdf) for the pre-publication copy and here (pdf) for its supporting technical analyses. You're welcome.