Whether the United States, which pulled out of Kyoto in 2001 and is the world's largest producer of greenhouse gases, agrees to that is uncertain.

The Kyoto protocol is an environmental pact ratified by 156 nations. Under the first phase, 39 developed nations must reduce greenhouse gases by 5 percent under 1990 levels from 2008 to 2012.

But environmentalists who have spent years attacking corporate America for dirty practices now sing the praises of companies like General Electric Co., BP Plc. and Dupont Co. which have found ways to pollute less.

"We made a decision long ago we are not going to debate anything on global warming, we are going to take the bull by the horns and reduce emissions," said Kevin Lowery, a spokesman for Alcoa Inc.

Fear that doing nothing to curb emissions of heat-trapping gases could lead to liabilities is spurring some companies to take action.

This year's Hurricane Katrina which killed at least 1,300 in New Orleans and Mississippi, and a record number of tropical storms, were reminders that many scientists say stronger storms are one of the potential effects of global warming.

And this year eight states and New York City sued five of the largest US utilities over carbon dioxide emissions. The suit is on appeal after a judge dismissed it.

Lowery said the aluminum industry is moving quickly toward becoming a climate-neutral industry as automakers use more of the metal to make lighter and safer cars.

Oil company BP has already met its self-imposed 2010 emissions target which is stricter than goals that about 40 developed countries must meet under the Kyoto Protocol. BP says that has saved the company $650 million.

Chemical company Dupont has beat its goal of reducing greenhouse gas emissions by 65 percent, in part by using renewable energy instead of fossil fuels.

"The science on global warming is sufficient enough to take prudent action," said a Dupont spokeswoman, who said the company has been so successful in meeting its environmental goals that it will propose new ones next year.

IBM and Bayer are also companies that have taken big steps in reducing emissions.

In the coal sector, Cinergy Corp. supports mandatory US caps on emissions and has set a voluntary goal of cutting emissions 5 percent below 2000 levels by 2010 to 2012. Spokesman Steve Brash said whether Cinergy will plot future goals will depend on what happens in 2006 when several bills in the US Congress calling for mandatory emissions cuts are expected to re-emerge.

Not everyone is convinced that a mandatory program is economically sound. Dan Riedinger, spokesman for Edison Electric Institute, said mandatory cuts would substantially increase power prices.

But many companies are preparing for the auditing and verification that emissions caps could bring. Utility American Electric Power Inc. is a big member of the Chicago Climate Exchange, the first voluntary emissions exchange in the United States.