EPA Administrator Lisa Jackson plans to announce today that she has determined that greenhouse gas emissions pose a danger to the public health and welfare. Once that endangerment finding becomes official, it will mark a fundamental shift in how the United States addresses human sources of climate change.
So how did we get here?
The endangerment finding directly stems from the Supreme Court ruling in Massachusetts v. EPA, but it has roots that go back more than a decade to a most unexpected source: The mouth of former Republican Rep. Tom Delay of Texas.
Here's how presidential climate advisor Carol Browner, President Clinton's EPA administrator during the 1990s, tells the story of Delay's unintentional role in the Obama EPA's endangerment finding:
"He and I got into a squabble one day in a hearing where he kept saying to me – this was back in the mid-'90s – 'You're regulating greenhouse gases.' I said, 'No, we're simply studying them.'
"This went back and forth for a while, and eventually he said, 'Well, do you think you have the authority to regulate them?'
"I said, 'You know, I never thought about it, I'm happy to take a look at the Clean Air Act, but the words don't appear in the Clean Air Act – greenhouse gases, climate change. But we'll take a look at it.'
"So I went back, and the lawyers took a look, and they wrote a memo saying, 'we probably do!' As we were leaving office, we updated that memo because there had been other activities pursuant to the Clean Air Act, and we left the memos behind.
"The Bush administration came along and said, well that can't possibly be the right interpretation. So, it was the memos that underlined the good leadership of the state of Massachusetts that led ultimately to the Supreme Court's decision, which is a profound decision."
The state of Massachusetts got involved in 2003, when the Bush administration refused to regulate greenhouse gas emissions from cars and trucks under the Clean Air Act.
Massachusetts sued, and in April 2007, the Supreme Court ruled that the EPA had the authority to regulate greenhouse gases under the Clean Air Act, and that it could not refuse to use that authority simply because of policy preferences.
The court ordered the Bush EPA to make a determination based on science. If the agency found a danger to public health and welfare, the EPA would have to begin setting standards to regulate greenhouse gases emissions from motor vehicles. But when the EPA sent the White House its determination as an e-mail attachment later that year, White House officials refused to open it.
Only now, under a new administration, is the EPA prepared to take action.