Wendy Koch

USA TODAY

At least 150 major companies worldwide — including ExxonMobil, Google, Microsoft and 26 others in the United States — are already making business plans that assume they will be taxed on their carbon pollution, a report out today says.

The U.S. has yet to impose a price on heat-trapping carbon dioxide emissions, but other nations are starting to do so as a way to address global warming, so U.S.-based companies are factoring an eventual one into their plans, says the international non-profit CDP, formerly known as the Carbon Disclosure Project. The report is the group's first one to look at corporate carbon pricing on a global scale.

"We're seeing companies taking steps they're not required to, and they're doing this to be competitive in a carbon-constrained world," says Zoe Antitch, spokeswoman of CDP North America, noting many do business in multiple countries. "They're looking ahead. ... They're climate ready."

The report comes one week before leaders of 100-plus countries convene Sept. 23 in New York City for the United Nations' Climate Summit, at which leaders of many nations and corporations are expected to announce their plans to reduce carbon emissions. The World Bank is calling for carbon pricing as a key strategy.

"A price on carbon creates incentives," Rachel Kyte, the World Bank Group's special envoy for climate change, told reporters last week. By hiking the price of fossil fuels such as oil and coal, which emit the most carbon dioxide when burned, she said it spurs investments in energy efficiency and non-polluting renewable power such as solar and wind. She said Canada's British Columbia has had a "revenue-neutral" carbon tax since 2008, and its CO2 emissions have fallen while its economy has grown.

Yet in the U.S., some business leaders and GOP members of Congress remain opposed to taxing carbon emissions, saying it could raise consumer prices for energy. They helped defeat President Obama's legislative push for a national cap-and-trade system in which overall emissions are capped but companies that exceed the limits can buy emission credits from those that emitted less.

So Obama's Environmental Protection Agency, acting without Congress, proposed in June to cut carbon emissions from existing U.S. power plants 30% by 2030. The EPA rule would allow states to meet varying reduction targets by closing coal-fired power plants, saving energy, using more renewable power or forming regional cap-and-trade programs.

California has its own such program, as do nine Northeastern U.S. states, which have created the Regional Greenhouse Gas Initiative or RGGI.

Other countries have adopted them as well. China, which has several regional programs, has announced it will implement a national cap-and-trade by 2020. The European Union began its Emissions Trading Scheme in 2005. It covers power plants and factories. The United Kingdom has its own program to include additional emitters.

London-based CDP, which surveys thousands of companies every year on their climate policies on behalf of institutional investors, found that 496 companies worldwide say they already participate in a carbon-pricing scheme, including 96 U.S.-based corporations. Of these U.S. companies, 69 say they're regulated by the EU's program.

The CDP's first report on corporate carbon pricing, released in December, looked only at U.S. companies. Like this year, 29 companies said they had placed an internal price on carbon, 18 of which appear in today's report. Those 18: Delphi Automotive, Walt Disney, Apache, Chevron, ConocoPhillips, Devon Energy, ExxonMobil, Hess, Cummins, Delta Air, Google, Ameren, American Electric Power, CMS Energy, Duke Energy, Entergy, Integrys Energy and Xcel Energy.

Eleven fell off last year's list, including Wal-Mart, General Electric and BP, but others joined this year's disclosure, including Microsoft, Bank of America, Dow Chemical and Goldman Sachs.

"We expect the number will be a lot higher next year," says Nigel Topping, CDP's executive director, noting his group will specifically ask companies whether they've placed an internal price on carbon. He says the 2013 and 2014 surveys did not do that, so companies had to volunteer the information. He says some that fell off this year's list may not have stopped pricing carbon but simply did not report it.

New Orleans-based Entergy, which runs power plants and provides electricity to customers in four southern states, uses a carbon price to help determine the "best mix" of future energy sources, says Chuck Barlow, its vice president of environmental strategy and policy.

U.S. companies report setting a range of carbon prices, from Microsoft's low of $6 per ton of carbon dioxide emitted to ExxonMobil's $80 per ton — up from $60 per ton last year.

"The risk of climate change is clear, and the risk warrants action," William Colton, ExxonMobil's vice president of corporate strategic planning, said in March in disclosing how the world's largest oil and gas producer assesses the risks of its fossil fuel assets. He said the company, which has shifted some of its production from oil to less-polluting natural gas, is trying to reduce greenhouse gas emissions in its operations and is supporting research that could lead to technology breakthroughs in energy.