Don't exhale. That advice may need heeding if the Environmental Protection Agency declares carbon dioxide and five other greenhouse gases dangerous pollutants, a move -- expected in the next couple weeks -- that would require the federal government to impose new rules limiting emissions. But some skeptics say regulating carbon dioxide, a byproduct of burning fossil fuels, may be a difficult task, especially since people emit carbon dioxide with every breath. "The EPA doesn't have the manpower to implement the regulations the way they would have to be," said David Kreutzer, senior policy analyst in energy economics and climate change at the conservative Heritage Foundation. Kreutzer said new regulations would trigger a flood of lawsuits, would create massive paperwork and the EPA should have no reasonable expectation that people would comply. In April, the EPA released its proposed finding that man-made pollution is a cause of global warming, triggering a 60-day comment period before the agency issues a final decision. The finding was prompted by a Supreme Court ruling two years ago that said greenhouse gases are pollutants under the Clean Air Act and must be regulated if found to be a human health danger. An EPA spokesman told FOXNews.com that no date has been set for a final ruling. "The EPA received over 300,000 comments on the proposal and is currently reviewing these comments in preparing the final rule," the agency said in a statement. Congressional aides, however, say the EPA likely will issue its final ruling next month when Congress reconvenes and its first proposal will be to blame auto vehicles for the emissions. That's just the start, however. Aides say later rules will extend to other sources and require a permit from the EPA to build anything that emits more than 25,000 tons of these pollutants. That could include schools, nursing homes or a Walmart. In addition to carbon dioxide, the EPA said five other emissions are believed to cause warming when they concentrate in the atmosphere: methane, which is emitted by gassy cows as well as steam boilers; nitrous oxide, found in cooking sprays and used as anesthesia by dentists, better known as laughing gas; hydrofluorocarbons, which are used in refrigerators and aerosols; perfluorocarbons, a gas permeated by fire extinguishers, refrigerators and high end ski waxes; and sulfur hexafluoride, more commonly known for its use in circuit breakers, switchgear and other electrical equipment. While the EPA follows its path, a climate change bill now working its way through Congress would also impose the first legislative limits on greenhouse gases, eventually leading to an 80 percent reduction by mid-century by putting a price on each ton of climate-altering pollution. President Obama has said he prefers that Congress act to pass the legislation rather than address climate change through administrative action. He said he wants a bill that utilizes market-based solutions to reduce carbon pollution and transition to a clean energy economy that creates millions of green jobs. The EPA is unable to use market solutions and lacks the authority to tax. A new Washington Post-ABC News poll says 55 percent of Americans approve of the way Obama is dealing with energy issues, including his plan to limit greenhouse gases with the climate change legislation, while 30 percent disapprove. By a somewhat narrower majority -- 52 percent to 43 percent -- Americans back a system that would set a ceiling for greenhouse gas emissions and would allow companies to buy and sell permits to emit the gases. "Most Americans would strongly support the president's and the bipartisan commitment to comprehensive legislation that addresses our dangerous addiction to foreign oil and create new jobs and addresses the climate crisis," said Vickie Patton, an attorney with the Environmental Defense Fund. Patton added that there's a "misinformation campaign designed to divide Americans instead of bringing Americans together to afford solutions." Senate Democrats want legislation passed before talks in Denmark in December on a new global treaty to reduce heat-trapping gases. But the legislation, known by opponents as "cap and trade," may be in trouble. In June, the House narrowly passed its version of the bill 219-212 after months of negotiations that led to last-minute deals and significant concessions to win the votes of moderate Democrats from industrial and agricultural states concerned about the costs that would be imposed on businesses in their districts. Further compromises will be needed for the bill to pass the Senate, which has tried and failed before to pass legislation to curb greenhouse gases. A GOP Senate aide told FOXNews.com that the Senate Environment and Public Works Committee will introduce a climate change bill on the same day senators return from summer break. Senate Majority Leader Harry Reid has set a deadline to have all committees working on climate change finish by the end of September, the aide said. But it's unclear whether Democrats are still pushing for a vote before December after the public backlash to Democratic-sponsored health care reforms. "We're starting to see hints that is no longer a viable option," the aide said, "especially given the number of Democrats who have expressed concern about cap and trade." Kreutzer said he believes the EPA decision is a tool being used by the Obama administration to pressure the Senate to pass the legislation. "None of this is surprising," he said. "There's a lot of people who want to use the bogeyman of EPA regulation to force people into the cap-and-trade bill. ... They don't want to give up that lever." Kreutzer called EPA regulation a "ransom" for climate change legislation. "It's a stone axe to go after something where you need a scalpel," he said. He suggested a simple solution would be for Congress to pass a one-line bill that declares carbon dioxide is not a pollutant. But it's an unlikely solution.