SNAP ANALYSIS: EPA says CO2 emissions endanger human health

* Joe Mendelson, global warming policy director at the National Wildlife Federation, said "the EPA decision is historic and a game-changer for climate policy that will have political and policy repercussions domestically and abroad."

"This is the single largest step the federal government has taken to fight climate change," he said.

* Charles Drevna, president of the National Petrochemical and Refiners Association, said "such regulation would have an enormous impact on every facet of the economy, businesses large and small, as well as on the general population."

"Before moving forward with regulation, the United States must ensure that other major global contributors are similarly committed to reducing their ambient greenhouse gas concentrations," he added.

* The move to regulate carbon through the EPA will likely place pressure on Congress to pass legislation to limit greenhouse gases. The House Energy and Commerce Committee hopes to clear such a bill by the end of May.

With the economy faltering, such legislation faces an uphill battle as detractors say it will raise energy costs for businesses and consumers.

* The White House has said it prefers for Congress to pass a bill that caps carbon emissions and requires companies to acquire permits to release carbon into the atmosphere.

"Today's action by EPA should give the Obama administration more ammunition to get Congress to do its job correctly," said Frank O'Donnell, president of environmental group Clean Air Watch. "The Obama administration now has the legal equivalent of a .44 Magnum (firearm). The bullets aren't loaded yet, but they could be."

* The EPA will accept public comments on the finding for 60 days. The agency will also hold two hearings on the proposal.

(Additional Reporting by Tim Gardner; Editing by Paul Simao)