While Mitt Romney does not support U.S. EPA's regulation of greenhouse gas emissions using the Clean Air Act, a recent court decision likely would limit his ability to unilaterally reverse the agency's approach, a surrogate for the presumptive Republican presidential nominee said today.

The endorsement by a federal appeals court of EPA's finding that greenhouse gases such as carbon dioxide endanger the public and should be regulated limits the leeway Romney would have to reverse the agency's new rules limiting the emissions from vehicles and power plants, said Linda Gillespie Stuntz, a former deputy energy secretary under President George H.W. Bush and founding partner of Washington law firm Stuntz, Davis & Staffier.

But he could push Congress to enact new legislation to block the rules, she added.

"I think the governor is on record that he doesn't believe greenhouse gases should be regulated under the Clean Air Act. I think before D.C. Circuit decision, he would have said if he had the choice, he would not regulate them under the Clean Air Act," Stuntz said. "I'm not sure he has that choice now under that law, and whether he would choose to seek legislation clarifying that GHGs could not be regulated under the Clean Air Act. But I know he thinks and I think it's an inappropriate vehicle for attempting to do that."

Stuntz represented the Romney campaign today at a energy policy debate hosted by the Business Roundtable. Speaking for President Obama's campaign at the debate was Dan Reicher, executive director of the Steyer-Taylor Center for Energy Policy and Finance at Stanford University and a former assistant energy secretary during the Clinton administration.

Stuntz said Romney campaign officials are still weighing their options when it comes to addressing EPA regulations. She did not rule out the possibility that the endangerment finding that provided the legal groundwork for the climate rules would be reversed by a Romney administration. One key variable, she said, is the fate of EPA's "tailoring rule," which exempts all but the largest sources of greenhouse gas emissions from the regulations.

The D.C. Circuit Court of Appeals dismissed a petition from states and industry groups challenging the tailoring rule, saying they lacked standing to bring the case, but the decision left open the possibility that the rule could fall in the future. The rule departs from the plain language of the Clean Air Act to set higher emissions limits because EPA said it would be impractical to regulate small sources such as schools, apartment buildings or small businesses.

"If in fact that were to be set aside by some future court and in fact we had to regulate greenhouse gas emissions down to the dry cleaner level, yeah, I think they might take a look at that endangerment finding," Stuntz said today.

While Stuntz and Reicher shared an optimistic view on the broader U.S. energy landscape, they differed sharply on issues including the role of government in regulating the energy industry, how much support should be provided for renewable energy and how best to address climate change.

Although Romney does not support EPA's climate regulations, he is "certainly not a denier" when it comes to the reality of climate change and the fact that human activities are contributing to rising global temperatures, Stuntz said. But he does not believe unilateral regulations in the United States would be effective because of rising emissions from countries in the developing world, such as India and China.

She said he would continue to support basic research into clean-energy technologies -- citing the Advanced Research Projects Agency-Energy (ARPA-E) as a successful model -- in the hope of creating a technological breakthrough that would allow clean sources to compete with traditional generation.

Reicher said the Obama administration supports efforts to reach a binding international agreement on climate change, and he pointed to efforts in the meantime to work with other countries such as China on a bilateral basis and through smaller international forums. He said that the administration is open to a variety of options to establish a price on carbon but that getting an international agreement is of paramount importance so as not to put the United States at a competitive disadvantage.

Reicher also endorsed a broader role for government in supporting new technologies, beyond basic research. While ARPA-E has established a successful model for developing technologies in a laboratory, government support is generally still necessary to commercialize new energy technologies, he said. Once the first plant is built, he said, the government can scale back its role.

He pointed to administration financial aid for development of carbon capture and sequestration technology, but Stuntz said such technology was economically infeasible and would remain so for the foreseeable future.

On renewable energy, Reicher dismissed criticism of the loan guarantee program that has haunted Obama and Democrats since solar panel manufacturer Solyndra declared bankruptcy last year. Reicher pointed out that Solyndra's $535 million DOE loan guarantee was a tiny piece of the overall program, which has generally performed beyond expectations.

Reicher also reiterated the administration's support for an extension of the production tax credit for wind, which expires at the end of this year. Stuntz said that although Romney is skeptical of government support for renewable energy in general, he has not taken a firm position on the PTC.