A sharp divide has emerged between two leading Republican presidential candidates on the issue of climate change. While apparent front-runner Mitt Romney believes the world is getting warmer and that humans are contributing to that pattern, Texas Gov. Rick Perry on Wednesday called that “a scientific theory that has not been proven.”

Taking questions at the storied Politics and Eggs breakfast in Bedford, N.H., Perry was asked about a passage in his book “Fed Up!”, in which he expresses skepticism of the science behind global warming.

In the book, Perry writes that there has been “doctored data” and accuses former vice president Al Gore, who won a Nobel Peace Prize for his call to action on climate change, of being a “false prophet of a secular carbon cult.”

“They have seen the headlines in the past year about doctored data related to global warming,” Perry writes. “They know that we have been experiencing a cooling trend, that the complexities of the global atmosphere have often eluded the most sophisticated scientists, and that draconian policies with dire economic effects based on so-called science may not stand the test of time. Quite frankly, when science gets hijacked by the political Left, we should all be concerned.”

Perry goes on to write: “It’s all one contrived phony mess that is falling apart under its own weight. Al Gore is a prophet all right, a false prophet of a secular carbon cult, and now even moderate Democrats aren’t buying it.”

At his New Hampshire campaign stop on Wednesday morning, Perry said: “I do think global warming has been politicized. ... We are seeing almost weekly or even daily scientists are coming forward and questioning the original idea that man-made global warming is what is causing our climate to change. Yes, our climate has changed. It has been changing ever since the Earth was formed. But I do not buy into a group of scientists who have, in some cases, been found to be manipulating data.”

Perry may have been referring to controversy over e-mails at the Climatic Research Unit at the University of East Anglia in Britain in which climate scientists discussed data flaws.

The scientists who sent the controversial e-mails were ultimately cleared of wrongdoing in multiple probes, which determined that there was no deliberate manipulation of scientific data. There is a broad scientific consensus that greenhouse gas emissions released by human activities such as fossil fuel burning helps account for climate change in recent decades, though this remains a source of fierce political debate within the GOP.

With his beliefs, Perry stands in stark contrast to Romney, the former Massachusetts governor who repeatedly has said on the campaign trail that he believes the science behind global warming.

At a June 3 town hall meeting in Manchester, N.H., Romney was asked about climate change. He said: “I don’t speak for the scientific community, of course, but I believe the world’s getting warmer. I can’t prove that, but I believe based on what I read that the world is getting warmer. And number two, I believe that humans contribute to that. I don’t know how much our contribution is to that, because I know that there have been periods of greater heat and warmth in the past, but I believe we contribute to that.”

Romney added that “it’s important for us to reduce our emissions of pollutants and greenhouse gases that may be significant contributors.”

He also said he does not support a cap-and-trade policy, saying it would put U.S. companies at a competitive disadvantage in the world. “We don’t call it ‘America warming,’ ” he said. “We call it ‘global warming.’ ”

The campaign of former Utah governor Jon Huntsman Jr. seized on Perry’s comments to portray the Texas governor as outside the mainstream with his climate change views. Huntsman himself does believe in the science behind global warming.

“We’re not going to win a national election if we become the anti-science party,” John Weaver, Huntsman’s chief strategist, said in an interview Wednesday. “The American people are looking for someone who lives in reality and is a truth teller because that’s the only way that the significant problems this country faces can be solved. It appears that the only science that Mitt Romney believes in is the science of polling, and that science clearly was not a mandatory course for Governor Perry.”

Romney’s line that “humans contribute” to climate change sparked an immediate backlash among some on the right, including conservative talk radio host Rush Limbaugh, who said: “Bye-bye, nomination. Another one down. We’re in the midst here of discovering that this is all a hoax. The last year has established that the whole premise of man-made global warming is a hoax, and we still have presidential candidates that want to buy into it.”

Staff writer Krissah Thompson in New Hampshire contributed to this report.