The Copenhagen Climate Council study said the United States would gain that many jobs if its electricity use grew by just half of 1 percent a year and a quarter of its electricity came from wind energy and other renewable sources.

EU Commission President Jose Manuel Barroso told the CEOs of major international corporations that similar investments could produce a million new jobs in European Union countries.

“Change also brings big economic opportunities,” he said.

The predictions came at a global business summit where corporate leaders are focusing on how to help politicians negotiate a new global climate treaty to succeed the Kyoto treaty that expires in 2012.

In 2007, EU leaders pledged that by 2020 the European Union would cut emissions of carbon dioxide and other major warming gases by at least 20 percent from 1990 levels, and increase its reliance on renewable energy sources to one-fifth of all its energy used.

“Achieving a 20 percent share for renewables, for example, could mean more than a million jobs in this industry by 2020,” Barroso said. Such a plan must be joined, he said, by “a satisfactory international climate agreement in which other developed and developing countries contribute their fair share to the limiting global emissions.”

Barroso said the EU intends to limit the cost of its package to about half of 1 percent of its GDP.

“Some people, however, have questioned whether this is the right direction for Europe during the economic crisis,” he said, but the answer is that “the costs of climate change will be much higher if we don’t make adjustments now.”

He said the hoped-for December agreement in Copenhagen on a U.N.-administered treaty will be “a major milestone on the path to a global carbon market which would increase business opportunities, particularly for European industry, and help to bring average carbon costs further down.”

BP PLC Chief Executive Officer Tony Hayward said most executives he had spoken with agree the world “is going to establish a carbon price” — making carbon emissions a global commodity, with a universally accepted price, probably through a so-called “cap-and-trade” system by governments and the marketplace.

“I think we can craft some pretty clear direction,” Hayward said.

That approach requires governments to sign a new U.N.-administered treaty for regulating greenhouse gases to set limits on carbon dioxide and then issue permits to companies that divvy up how much of the overall pollution each of them can emit. Any unused portions can be traded to other companies.

The other option is a direct carbon tax, favored by some at the meeting.

Also Monday, at a meeting in Paris, France’s environment minister urged the world’s biggest polluters to slash carbon emissions to slow what he called the probably irreversible tide of global warming.

Just how far governments are willing to go is the key question at talks in Paris this week among top environment officials from the United States, China and 15 other high-polluting nations.

“No one contests the urgency of the problem,” French Environment Minister Jean-Louis Borloo said in opening the Major Economies Forum talks. “No one contests the probably irreversible character of the problem.”

Activists say governments of rich countries are not being ambitious enough in their emissions targets, and protests outside the French Foreign Ministry are planned during the two-day meeting.

The environment chiefs also are discussing how to raise $100 billion a year to help poor countries adapt to climate change. Getting such countries on board is seen as important to reaching the global climate pact at meetings in Copenhagen in December aimed at replacing the 1997 Kyoto Protocol.

The countries represented at the Major Economies Forum account for 80 percent of the global emissions of heat-trapping gases.

Solar and wind-power companies, energy-efficient light bulb makers, environmental engineering firms and others expanded their work force by 9.1 percent from 1998 to 2007, the latest year available, according to Pew.

The average job growth in all industries was 3.7 percent during the same period.

The entire energy sector has experienced growth in recent years as well, according to the Bureau of Labor. Bureau data shows coal mining jobs jumped 16 percent from 2003 to 2009. Oil and gas extraction jobs jumped 28 percent.

The Pew study does not include employment data from the past 18 months, a volatile period for the energy industry.Since the data was collected, the government has said it would pump billions into renewable energy and effiency programs. The banking meltdown made it nearly impossible to raise cash and oil prices have collapsed.

Alternative energy companies have been hit hard by the recession, with a string of bankruptcies in the ethanol industry and layoffs in the wind-power industry.Lori Grange, Pew’s interim deputy director, said that while green industries will certainly benefit from the influx of billions in stimulus dollars, the report shows that the clean energy sector has proven itself sustainable.

States like California, Texas, Florida, and New York continue to employ the most people in the industry. However, states experiencing the largest growth rates were Idaho, Nebraska, South Dakota and Wyoming, according to the report.

Michigan, which has lost hundreds of thousands of manufacturing jobs, saw a 10.7 percent increase in clean energy jobs from 1998 to 2007.That is not to say that clean energy jobs have kept pace with overall job losses.Pew counted 22,674 clean energy jobs in Michigan in 2007. To put that into perspective, Michigan lost 38,400 jobs in April alone.

Many of the new manufacturing jobs do not pay as well as traditional union jobs, either, yet workers who have made the shift say the industries are moving in different directions.One cast off from the auto industry is Bob Mamo, 50, who was director of business development for a Dearborn, Mich., auto parts supplier until he was laid off in November. He was in the industry for 20 years.

Last month, he landed a job as vice president of manufacturing for Free Flow Power, a hydropower company based in Gloucester, Mass.The auto industry “just looked like it was going in the wrong direction,” he said. “Green energy is definitely on the upswing. Green energy was what I was really after.”

Liesl Clark, deputy director for Michigan’s Department of Energy, Labor and Economic Growth, said the state is doing what it can to help manufacturers shift operations to supply parts for wind turbines, such as gear boxes and drive trains.

For its study, Pew used private jobs data that included information about employers, and Pew researchers spent nearly a year determining which ones could be considered part of the clean energy economy.

“Our numbers are probably conservative,” said Kil Huh, who directed the study. “If we couldn’t identify as part of green energy, it wasn’t part of our count.”

The Pew jobs data was dominated by environmental engineering firms and other pollution cleanup specialists that have been around for years. But the report showed that the fastest growing areas include companies that make hybrid diesel buses, traffic monitoring software, liquid biofuels, and jobs related to solar and wind energy.

“The explosive growth is really in clean energy,” Huh said.