Romney's comments suggest shifting stance on climate change science

Former Massachusetts governor and Republican presidential candidate Mitt Romney seems to be shifting his stance on climate change as he grapples with insurgent newcomer Texas Gov. Rick Perry (R), who has raced to the top of GOP polls.

"Do I think the world's getting hotter? Yeah, I don't know that, but I think that it is," Romney said in New Hampshire on Wednesday, according to Reuters. "I don't know if it's mostly caused by humans."

But at an earlier event in June in New Hampshire the former Massachusetts governor seemed more convinced by the possibility of global warming.

"It's important for us to reduce our emissions of pollutants and greenhouse gases that may be significant contributors," Romney said in June. "I believe the world is getting warmer, and I believe that humans have contributed to that."

The vast majority of scientists believe the planet is warming in large part due to human activity, but the issue has become highly politicized among GOP candidates. Perry made headlines when he said last week that climate change was “a scientific theory that has not been proven.” In his book Fed Up!, the governor wrote that climate change is “all one contrived phony mess that is falling apart under its own weight.”

While Perry's remarks were criticized by some in the party — fellow candidate Jon Huntsman made a point to tweet his belief in global warming — the Texas governor has gained traction among voters. In the latest nationwide polls, Perry is leading Romney by double digits, which might be contributing to Romney's apparent softening on climate science.

But a Romney shift also risks playing into the "flip-flop" narrative that has dogged his campaign on issues like universal healthcare, abortion rights and the tax code.

At Wednesday’s event, Romney said he believed weaning the U.S. from Middle Eastern oil was more important that reducing greenhouse emissions. He went on to criticize the "cap and trade" bill supported by the White House that would have capped carbon emissions and given manufacturers the ability to buy and sell rights to emit carbon.