Climate Change Update: The Center for Public Integrity: SLIDESHOW: A guide to the Republican candidates' views on climate change

The Center for Public Integrity: SLIDESHOW: A guide to the Republican candidates' views on climate change: Many if not all scientists and climate specialists agree that the Earth's climate is changing and that humans have driven those changes. Both the United Nations' Intergovernmental Panel on Climate Change and the U.S. Global Change Research Program , the leading international and domestic climate research organizations on climate change, report similar conclusions. "Global temperature has increased over the past 50 years," noted the U.S. research program in a 2009 report . "This observed increase is due primarily to human-induced emissions of heat-trapping gases."

Of the front-runners, only former Massachusetts governor Mitt Romney has gone on the record as accepting climate change; he stresses the importance of reducing pollution that contributes to global warming. Michele Bachmann and Rick Perry take the opposite view, criticizing the EPA, which Bachmann vows to shut down except for overseeing conservation. Congress and President Richard Nixon, a Republican, created the agency in 1970, in response to growing public demand for cleaner air, water and land.