This story, originally published in February, has been updated.

NEW YORK (CNN/Money) -- Government caps on the emission of global-warming gases could cost big bucks for companies forced to comply with the rules. But has the business world come to terms with the financial implications of climate change?

And though the costs could be high for some, other companies seem much better positioned. A few may even be poised to benefit.

"Some firms have already moved ahead," said David Victor, director of the Program on Energy and Sustainable Development at Stanford University.

Innovest Strategic Value Advisors, an investment research firm specializing in analyzing companies' performance on environmental issues, identified a "top 100" list of companies that are most open to environmental regulations.

For instance, General Electric (Research) has set its sights on the growing wind power market and may see a windfall from clean energy technologies.

The company's financial arm also recently announced an initiative to provide financial solutions to the growing number of companies focused on clean energy and related technologies.

Cummins Inc. (Research) has sold thousands of compressed natural gas bus engines to Beijing, which has the world's largest bus fleet operating on clean energy. Cummins has also established a business relationship in India to introduce natural gas engines there, the company said in a statement.

BP (Research), owner of one of the world's largest solar power businesses, is introducing lower-emissions fuels at its retail outlets.

"We'll continue to shift the balance of our business in favor of lower carbon energy sources and in particular natural gas," Group Chief Executive John Browne said in a statement.

The No. 1 aluminum producer, Alcoa (Research), is poised to benefit from the auto industry's adoption of aluminum to create fuel-efficient vehicles with better strength-to-weight ratios that produce lower emissions.

Aluminum's use in vehicles is rapidly increasing due to a heightened need for fuel efficient, environmentally friendly vehicles, according to the Aluminum Association.

Toyota Motor (Research)'s investment in environmental technology for the auto industry will also position the automaker well to face new climate change policies. Hybrids are already in high demand, but production levels have been relatively small. Still, Toyota's hybrid Prius was the fastest selling car in the U.S. last year.

"If automobile efficiency gets serious then hybrid cars may not be the best choice," Victor warns.

Companies that produce new generation diesel engines, for example, may turn out to be the big winners. "With advanced fuels there are next-to-no traditional air pollutants, making diesel engines amazingly efficient," according to Victor.

With the manifestation of legitimate and credible emissions rules, some firms with access to new technologies may emerge relatively quickly.

And with research increasingly indicating a demand for climate change policy, it is likely that more companies will address their own preparedness.

Concerns that the greenhouse effect poses a serious threat to the global environment are not new. Now that a United Nations plan to limit emissions of greenhouse gases has taken effect, companies in participating countries face more stringent regulation.

The Kyoto protocol was enacted Feb. 16 and requires 38 of the world's industrialized nations -- including Canada, Japan, Russia and all of the European Union -- to reduce greenhouse gas emissions 5 percent below 1990 levels by 2012.

The U.S. emits approximately 25 percent of the world's greenhouse gases, according to the Energy Information Administration, but is not a participant in the Kyoto Protocol, arguing it is too costly.

The State Department said the White House is committed to cutting greenhouse gas emissions and recently announced it will spend nearly $5.8 billion in 2005 on research and programs addressing climate change.

Climate change policy in response to the greenhouse effect aims to limit emissions of certain gases, including carbon dioxide, methane, nitrous oxide, water vapor and chlorofluorocarbons, that trap the sun's heat in the Earth's atmosphere and are believed to raise global temperatures and disrupt weather patterns.

According to the United Nations Intergovernmental Panel on Climate Change (IPCC), deforestation and the burning of fossil fuels have increased the amount of greenhouse gases in the atmosphere and caused rising temperatures. In addition, all carbon dioxide emissions, some natural and some caused by burning of fossil fuels, will continue to heighten the greenhouse effect.

Some critics of the IPCC report say the temperature changes from the 20th century are within the bounds of normal variability. Others cite faulty research data, and believe surface temperatures alone do not provide the best gauge of climate change.

In an interview with the BBC, James L. Connaughton, chairman of the United States Council on Environmental Quality, said that the science was still contested. "We are still working on the issue of causation, the extent to which humans are a factor," he said.

Check out the Changing Earth special on cnn.com here.

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