GOP candidate Kevin Coughlin says there's not much evidence to support human role in global warming

Kevin Coughlin, a former Republican state legislator from Cuyahoga Falls, has been making Ohio’s political rounds this summer in an effort to capture his party’s nod to take on Democratic U.S. Sen. Sherrod Brown next year.

At an Aug. 18 stop in Strongsville, Coughlin told the Strong Ohio tea party group he believes the science behind global warming is "sketchy."

"Scientists who consider themselves to be environmentalists disagree on the science and the impact," Coughlin said. "There is no question that the earth’s core is increasing slightly in temperature.

"But the real question and I think what’s pertinent to the debate in our country and in global politics is how much people really contributed to it and I don’t really think there’s much evidence to suggest that people have or can do very much to change anything."

That got PolitiFact Ohio’s attention.  

We contacted Coughlin, whose appearance was captured on video by a Democratic super PAC, American Bridge 21st Century. He acknowledged making the remarks, although he said meant to say the Earth’s atmosphere -- not its core -- is rising in temperature.

But do scientists agree with his assertion that there’s not "much evidence to suggest that people have or can do very much to change anything."

Many Republican politicians apart from Coughlin assert that scientists disagree whether human actions contribute to global warming.

Before he dropped out of the GOP presidential primary last month, former Minnesota Gov. Tim Pawlenty told the Miami Herald newspaper "the science is in dispute" over "how much, if any" climate change can be blamed on human behavior. At an Aug. 17 New Hampshire campaign stop, Texas Gov. Rick Perry said that scientists are regularly "coming forward and questioning the original idea that man-made global warming is what is causing the climate to change."

PolitiFact examined these claims by Pawlenty and Perry, and found them to be False. That’s because there does appear to be a scientific consensus that people contribute to global warming.

To begin with, a 2007 report from the U.N. Intergovernmental Panel on Climate Change, the world’s leading international scientific body on climate science, states: "Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. The observed widespread warming of the atmosphere and ocean, together with ice mass loss, support the conclusion that it is extremely unlikely that global climate change of the past 50 years can be explained without external forcing, and very likely that it is not due to known natural causes alone." (External forcing refers to anything that changes the climate that is outside of the normal climate system.)

A 2009 report from the U.S. Global Change Research Program reached a similar conclusion: "Observations show that warming of the climate is unequivocal. The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases. These emissions come mainly from the burning of fossil fuels (coal, oil, and gas), with important contributions from the clearing of forests, agricultural practices, and other activities."

Current climate change research was reviewed again this year by the National Research Council and the National Academy of Sciences. The committee it assembled concluded that global warming poses significant risks and is happening primarily because of greenhouse gas emissions from human activities. It rejected the idea that those findings are in any way questionable.

"Although the scientific process is always open to new ideas and results, the fundamental causes and consequences of climate change have been established by many years of scientific research, are supported by many different lines of evidence, and have stood firm in the face of careful examination, repeated testing, and the rigorous evaluation of alternative theories and explanations," the committee’s report said.

A few scientists dispute the IPCC’s conclusions on global warming, but most acknowledge that humans contribute to increased temperatures. They make more nuanced points, like  questioning whether carbon emissions by themselves are enough to boost temperatures, whether other human activities contribute, whether rising temperatures cause severe weather, and whether public policy change is needed to address potential problems.

Climate change skeptics cite an online petition with more than 31,000 signatures to demonstrate their viewpoint is widespread. The petition states "there’s no convincing scientific evidence" that human greenhouse gas releases are disrupting the Earth’s climate, and there’s "substantial evidence that increases in atmospheric carbon dioxide produce many beneficial effects" on Earth’s plants and animals. That petition has been criticized for not checking the credentials of its signatories or even proving they exist.

But surveys of large numbers of climate researchers show a clear consensus among them that humans are causing climate change.

One 2010 study, published in the Proceedings of the National Academy of Sciences, found that 97 to 98 percent out of 1,372 climate researchers who are publishing scientific studies in the field say they believe that human beings are causing climate change, and that the scientific credentials of researchers who doubt that role are "substantially below that of the convinced researchers."

A study published the previous year by the American Geophysical Union, asked more than 3,100 scientists whether they think human activity significantly contributes to "changing mean global temperatures." About 82 percent of the surveyed scientists answered "Yes," with a 97.4 percent affirmative rate among climate change specialists.

While a few skeptics out there disagree, there’s clear scientific consensus that global warming is occurring and that humans contribute to it. Disagreement on the subject is scant enough that we rule Coughlin’s statement is False.

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