As it debated global warming legislation, the Senate gave little thought in June to questions about U.S. EPA using its existing authority to regulate greenhouse gas emissions.

Times have changed.

With EPA's rollout of a nearly 500-page advanced notice of proposed rulemaking in July, lawmakers are now on notice about how far the government could go with White House approval to start writing rules for regulating emissions for everything from power plants to cars, airplanes, restaurants, dry cleaners and bakeries.

Nothing heats the blood of foes of environmental regulation like the threat of taking away their lawn mowers.

So anti-regulation forces are shaping a national debate about curbing U.S. emissions of greenhouse gases -- a debate that on Capitol Hill has focused on power plants and the automobile industry -- as a green-shirted grab for power tools and barbecue grills.

Early public comments on U.S. EPA's July rulemaking notice on how it might use the Clean Air Act to tackle global warming pollution suggest that regulation foes are taking that tack.

At least two key U.S. EPA documents showing the agency's response to the Supreme Court's 2007 Massachusetts v. EPA decision remain under wraps.

One is the agency's "endangerment finding" linking motor vehicles' greenhouse gas emissions to global warming's environmental problems. The other is a 350-page draft regulatory proposal to curb emissions from cars, trucks and fuels.

The Senate Environment and Public Works Committee members saw the "endangerment finding," but they did so under the supervision of White House lawyers and then only after threatening to subpoena the document. Members of the House Select Committee on Energy Independence and Global Warming have reviewed both documents at a closed-door session last month.

After a decade of petitions, court cases and political promises on climate change, U.S. EPA finally revealed last month how it could use the Clean Air Act to curb greenhouse gases.

The agency suggested in a nearly 500-page document using climate-related permits for new power plants and other industrial facilities, a cap-and-trade program for limiting emissions across many economic sectors, and a nationwide limit on carbon dioxide akin to standards used for lead, carbon monoxide and other pollutants.

The report's prologue was written by eight senior-level Bush administration officials who made clear their distaste for EPA tackling climate regulation.