FACTBOX: U.S. EPA's moves against climate change

(Reuters) - As the U.S. Congress fights over legislation to reduce greenhouse gas emissions blamed for global warming, the Obama administration is considering a series of regulations that also would cut such pollutants.

Legislation would be more comprehensive, but if Democrats in Congress fail to agree on a bill, the Environmental Protection Agency is expected to move ahead over the next several months.

Here is a rundown of actions the EPA is weighing:

*AUTO EMISSIONS:

In May, President Barack Obama announced he would seek tougher fuel economy for all cars and light trucks sold in the United States. Those vehicles would have to achieve 35.5 miles per gallon, saving 1.8 billion barrels of oil and reducing greenhouse gas emissions by an estimated 900 million metric tons.

EPA is working on a regulation. Congress' climate change bills do not directly deal with such auto emissions, so this initiative is likely to proceed no matter what happens on Capitol Hill.

*ENDANGERMENT FINDING:

In April, EPA announced it had found that greenhouse gases contribute to air pollution that can endanger public health and that climate change "is an enormous problem." The agency also said it could regulate those gases, including carbon dioxide, under the Clean Air Act. EPA is still reviewing public comments that could lead to a final "endangerment finding," which could provide the underpinning for climate control regulations.

*EMISSION REDUCTIONS

The final "endangerment" finding would clear the way for EPA to set forth rules, possibly next year, that would regulate greenhouse gas emissions under the Clean Air Act. Some moderate Democrats in Congress argue that the regulations could be more onerous on business than anything lawmakers would pass and are urging the House and Senate to act fast to pre-empt stronger EPA action.

*GREENHOUSE GAS REGISTRY

In March, EPA proposed creating a national registry for reporting greenhouse gas emissions to measure the amount of pollutants before undertaking reduction efforts. The agency says about 13,000 facilities, accounting for up to 90 percent of the U.S. emissions, would be covered. Businesses that emit at least 25,000 metric tons of greenhouse gases per year would have to participate, which would exempt most small businesses. EPA estimates it would cost industry about $160 million in 2011, the first year of the registry, falling to $127 million in subsequent years.

A public comment period has ended and a final rule is being reviewed by the White House.

(Reporting by Richard Cowan, Editing by Stacey Joyce)