"What I'm not willing to do is spend trillions of dollars on something I don't know the answer to," Romney said.
Romney also said on Wednesday that he would make weaning the United States from imported energy from the Middle East a priority over reducing carbon emissions.
Still, using additional domestic nuclear, natural gas, and other resources could have a side benefit of cutting carbon emissions, Romney said. "My view is pursue a strategy which gets us into energy independence which has as a byproduct it gets us into less CO2 emitting."
He criticized a bill backed by President Barack Obama that would have capped carbon emissions and allowed polluters to buy and sell rights to emit carbon.
"I do not believe in cap and trade and I do not believe in putting a carbon cap" on polluting industries, Romney said.
This is a big change from the Romney of early June, who raised eyebrows when he went against Republican dogma and talked the talk of climate change.
"It's important for us to reduce our emissions of pollutants and greenhouse gases that may be significant contributors," Romney said at another New Hampshire stop in early June.
"I believe the world is getting warmer, and I believe that humans have contributed to that," Romney said at the event.
Perry's poll numbers are surging, and there are signs that he's taken Romney's mantle as the early frontrunner in the 2012 nomination contest. Romney's new opposition to doing anything actively to prevent climate change may be a sign that he's trying to skew farther right to grab some of that Perrymentum.
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