THE ENVIRONMENTAL Protection Agency announced Monday that it has determined that six heat-trapping "greenhouse gases" - especially carbon dioxide and methane - pose a danger to public health.
This "endangerment finding" is the first step in allowing the EPA to enforce the Clean Air Act by regulating emissions from fossil fuels used in cars, power plants, oil refineries and other industries.
The announcement came, not coincidentally, on the day that representatives from 190 countries began meeting in Copenhagen to try to begin . . . to take the first steps . . . to lay the groundwork . . . to create a structure . . . for a future plan . . . to reduce global warming. Tentatively, that is.
President Obama reportedly plans to commit the United States to reduce greenhouse-gas emissions by 17 percent from their 2005 levels by 2020 (really only 4 percent if measured using the same standards as the rest of the world does).
The EPA announcement also allows him to demonstrate that his administration could take action against global warming even if Congress doesn't pass the "cap and trade" legislation now stalled in the Senate.
With the time running out in the race to prevent a global catastrophe, that's all he has.
The awful truth is that, while there is a scientific consensus on global warming in the United States, there still isn't a public consensus. For that we can thank eight years of obstruction by Obama's predecessor.
A report this week by the Center for Responsibility and Ethics in Washington illustrated the influence that industry exercised in the Bush administration: At least 22 Bush-era officials walked out of the White House and into big jobs in the energy industry.
The anti-environmentalists have also scored another victory by pumping up a scandal over e-mails hacked from a British research center that they claim show scientists inflating evidence of global warning, a charge disproved by multiple news organizations.
Yet even as the Global Meteorological Organization declared the past decade to be the hottest on record, many Americans likely paid more attention to an op-ed in the Washington Post by Sarah Palin that ripped the Copenhagen summit for its alleged "agenda-driven" science.
Even though the EPA's announcement is a big step forward, experts warned that any new regulations likely will be challenged in court, and tied up for years. Still, even the threat of the EPA regulations could leverage congressional action on cap and trade. (That's the program to gradually cap emissions by allowing "cleaner" industries to trade pollution credits with "dirtier" ones, reducing economic hardship and providing incentives to develop alternative energy sources.)
Some environmentalists say cap and trade is too little, too late, but it's probably the only action that's politically possible. At the same time, passing it will be an ordeal - if the fight over health care is any indication of how Congress deals with legislation that displeases its corporate donors.
MEMBERS OF CONGRESS should meet Mohamed Axam Maumoon, 15, who lives in the Maldives, a group of islands in the Indian Ocean and who is attending the Copenhagen conference.
Most of Maumoon's homeland is just above sea level, making it one of several countries that would be destroyed if the predicted rise in sea level caused by global warming isn't averted.