Preparing for a major international climate conference now meeting in Geneva, the World Meteorological Organization circulated a draft declaration reflecting the commitment of European governments to stabilize the production of gases believed to cause global warming.

The United States responded with a series of caveats and weakening amendments as long as the declaration itself.

While virtually every Western industrialized nation has committed itself to specific timetables for stabilizing or reducing the gases that cause the greenhouse effect, the Bush administration remains skeptical that global warming is scientifically valid and refuses to take any direct action that threatens the way the United States generates energy and runs its economy.

Emphasizing the wait-and-see policy, White House Science Adviser D. Allan Bromley noted the administration has budgeted $500 million budget for research into climate change and said more conclusive evidence is necessary before the nation restricts use of critical fossil fuels -- oil, coal and gas -- that produce carbon dioxide when burned.

"I think the taxpayers would want that," he said in an interview.

As head of a White House task force on global warming, Bromley has played a key role in the administration's efforts to develop a cohesive policy on global warming. The group meets every six weeks and reports to the domestic policy council and White House Chief of Staff John H. Sununu, the leading skeptic of global warming.

Environmental Protection Agency Administrator William K. Reilly is the strongest advocate of direct action on global warming within the administration, but has fought an uphill battle against economic conservatives led by Sununu. And he lost a key ally when Secretary of State James A. Baker III, who has sided with Reilly on key policy disputes with Sununu, including last February's decision by Sununu to water down a speech Bush delivered to an international conference here, recused himself from policy debates that could influence his oil and gas interests.

Anticipating how isolated the United States will be in Geneva, Reilly, sources said, warned John Knauss, director of the National Oceanic and Atmospheric Administration, the administration's representative at the conference: "Roll up your sleeves and give blood, John. We're just going to get beaten up."

The administration's caution on the issue has been a disappointment to environmentalists, given President Bush's pledge during his 1988 campaign to use the "White House effect" to combat the "greenhouse effect," the popular term for describing the effect of gases that blanket the Earth and trap solar heat. The buildup of those gases has led to fears that the planet will warm significantly.

European governments, with popular environmental movements to placate, have created pressure for Bush by moving faster with concrete targets for stabilizing emissions of greenhouse gases by the turn of the century. But the administration defends its go-slow approach by noting the economic and political differences from Europe, where nuclear energy and high energy taxes are accepted alternatives. The United States also has further to go to combat per capita emissions of carbon dioxide, which more than double those of Japan and France.

In place of targeted cuts, officials such as Bromley point to research programs and the incidental carbon dioxide reductions achieved by other environmental policies. Still, carbon dioxide emissions are expected to grow 15 percent by the year 2000.

"They don't want to think about the tough decisions they would have to make if they admitted the problem is real," said Sen. Albert Gore Jr. (D-Tenn.), a leading critic of the administration's global warming position.

A year ago, Bromley said the administration would await the outcome of a U.N.-sponsored assessment of global warming before formulating remedial policies. But when the report in late September concluded that the planet will warm 5 degrees by the end of next century, Bromley said it raised as many questions as it did answers.

"Before we commit ourselves to massive mitigation schemes, we want to be sure of what the costs and what the effects will be, particularly on a regional basis," Bromley said.

Bromley said, for example, that of the six major climate models, three predict that the American midwest will be hotter and drier in the coming century, while three predict cooler, wetter weather. He has repeatedly said that the climate models are not accurate enough to base public policy.

For the present, many members of the scientific community support a "no regrets" policy, in which the United States and other governments would attempt to limit the production of carbon dioxide and other gases for reasons that made sense even if there is no significant warming trend in the world climate.

The administration supports such "an insurance policy," said Bromley, even as it remains skeptical over the prospect of global warming. Passage of the Clean Air Act, he said, will limit any possibility of warming, he said, since it will foster more efficient use of energy. The United States is also committed to phasing out chlorofluorocarbons (CFCs), another important warming gas.

But more ambitious plans to cut carbon dioxide run into the hard realities of an economy dependent on fossil fuels as its energy staple. Economic models to predict the cost of mitigating global warming are still in their infancy. While some analyses make the cost seem almost negligible, others project huge costs, which have been a major cause of concern for Sununu and other administration officials.

An interagency group formed by the Energy Department recently put the costs at $50 billion a year -- or 1 percent of the nation's annual Gross National Product -- to stabilize global warming emissions by the year 2005.

"You're talking about major changes in the structure of economic activity," said Richard Schmalensee, a member off the White House Council of Economic Advisers. "There is the brute fact we use a lot of energy. If you're going to cut down carbon dioxide, you're going to have to figure out how to use less coal. History gives us no reason to think it will be cheap."

According to the Energy Department, the price for stabilizing global warming emissions by 2005 would be a tax of $100 on each ton of carbon contained in fossil fuels. That would nearly triple the price of coal and double the price of oil.

"If you impose unnecessarily high taxes or punitive measures on one sector of the economy, you might penalize economic growth," said Mark Kerrigan, associate deputy undersecretary of energy.

At yesterday's meeting in Geneva, the United States appeared to prevail in its efforts to water down the conference declaration to be issued on the final session Wednesday.

While the preliminary text had proposed specific targets to stabilize emissions by industrialized nations, the latest draft "welcomes" the European commitments but omits any reference to responsibilities of other countries.