The ruling the EPA is expected to make will bring US policy into legal accord with European standards and legislative packages, all of which address scientific evidence the assertion that climate change is the main detrimental side effect of human energy and industry.

It is also likely to ignite intense battles across the board as industries from coal-fired power plants and Detroit’s auto makers to office buildings and even corner coffee shops brace for what could be stiff new regulations.

The EPA decision to issue a finding, which will most likely take force in stages over the next several months, would have a significant impact on transport, manufacturing costs and how utilities generate power as the Obama administration addresses warnings about the gasses responsible for global warming that have long gone ignored.

In interviews to two US media outlets in the wake of the signing of President Barack Obama’s stimulus package Tuesday, EPA administrator Lisa Jackson said her agency will make a determination on whether carbon dioxide is a pollutant that endangers public health.

The agency was ordered by the US Supreme Court during the Bush administration – which ignored the order – to decide this question despite near-unanimous belief among agency experts that research points directly to such a finding.

At issue, then, is whether the agency will use its regulatory power to mandate emissions reductions, or whether climate change legislation will be put before Congress for debate. 

In interviews with the New York Times and the Associate Press – her fist since taking up the EPA’s reigns – Jackson cautioned that, while the EPA is on no timetable to issue emissions regulations, the ignored Bush era Supreme Court ruling on Massachusetts vs. EPA obligated her to act.

“It places EPA square in the centre of the discussion on climate and energy,” Jackson told the Times. “People are waiting.”

Jackson told the Times that the stir to put carbon emissions under the microscope now and issue a finding as the second anniversary of the Supreme Court decision – April 2nd – is fast approaching.

Jackson said that her staff will be reviewing the latest scientific data and prepare documentation for an endangerment finding on greenhouse gasses, the legal trigger for their regulation under federal law.

"We are going to be making a fairly significant finding about what these gases mean for public health and the welfare of our country," Jackson told the AP.

The Bush administration worked to stymie such a finding and did nothing to move the agency forward in making this determination.

Recent EPA decisions have hinted that the agency was leaning toward using the Clean Air Act to regulate the gases, a step the Bush administration refused to take despite prodding from the Supreme Court.

"It is clear that the Clean Air Act has a mechanism in it for other pollutants to be addressed," Jackson said.

"If EPA is going to talk and speak in this game, the first thing it should speak about is whether carbon dioxide and other greenhouse gases endanger human health and welfare," she said. "It is a very fundamental question."

The White House signaled that it fully supports Jackson’s approach, deferring to her to discuss the administration’s response to the Supreme Court case, said the Times

Jackson, a Princeton University-educated chemical engineer, headed the New Jersey Department of Environmental Protection from 2006 until 2008, when she accepted then President-elect Barack Obama’s invitation to head the EPA.

If the EPA determines that carbon dioxide is a dangerous pollutant that should be regulated under the Clean Air Act, it would set off one of the most extensive regulatory rule makings in US history.

Jackson knows that she would be stepping into a minefield of Congressional and industry opposition, and told the paper that she was trying to devise a programme that allayed these worries.

“We are poised to be specific on what we regulate and on what schedule,” Jackson told the Times. “We don’t want people to spin that into a doomsday scenario.”

But many who are in favor of aggressive action on the EPA’s behalf are also cautious about a regulatory approach that does not involve Congressional debate, an approach that could snag the initiative in courts for years, said the paper.

David Bookbinder, chief climate counsel at the Sierra Club, said Congressional action is preferable to the EPA acting on its own.

“We are loudly advocating for tailor-made legislation as the best means of addressing carbon emissions,” said Bookbinder. 

“Trying to address climate change via a series of rule makings from EPA is a distant second best.”

The Sierra Club was a plaintiff in the Supreme Court case that has sparked Jackson’s response.

Jackson said the finding the EPA will work to produce and proposed regulations would be issued in sequence, with ample opportunity for public comment and not in a sudden burst of regulatory pressure. The regulations would work in concert with any legislation and not supplant it, she added.

But many in Congress, Democrats and Republicans alike, have already sounded warning bells about state dependent on coal and manufacturing jobs. Democratic Michigan Representative and long time auto-industry supporter John Dingell, said regulating carbon dioxide emissions would make a “glorious mess” he told the Times.

Republican Senator John Barrasso of Wyoming told the paper the use of the Clean Air Act to regulate carbon “a disaster waiting to happen.”

The Sierra Club’s Bookbinder said EPA regulation was long overdue, but that regulatory moves should only be stopgap measures until Congress is able to pass climate change legislation, said the Times.

He said the EPA’s pursuit of a finding on greenhouse gasses pursuant to the Supreme Court decision is, “politically necessary, scientifically necessary and legally necessary.”

Jeffrey Holmstead, the former head of the EPA’s office of air and radiation, told the paper that any source emitting more than 250 tons of a declared pollutant would be subject to regulation under the Clean Air Act, potentially including schools, hospitals, shopping centers, even bakeries.

Bookbinder disagreed, saying legislation could be crafted such that it exempts certain entities.