Get PolitiFact in your inbox.

By W. Gardner Selby May 2, 2013

Wayne Smith says science has not shown greenhouse gases to be a problem

Wayne Smith does not sweat greenhouse gases.

"Science has not shown greenhouse gases to be a problem," the Republican Baytown state representative told the Austin American-Statesman for a news article posted online April 17, 2013.

Smith, who seeks legislative approval of a proposal to have the state issue permits for such industrial emissions, also said that nevertheless, "there’s no need to regulate greenhouse gases." House members sent his proposal to the Senate that week.

We explored whether science has not shown greenhouse gases--meaning various gaseous compounds (such as carbon dioxide) that absorb infrared radiation, trap heat in the atmosphere and contribute to the greenhouse effect--to be a problem.

Smith, who represents a district that is home to petrochemical plants, did not respond to telephone inquiries, but we ran his claim by Paul C. "Chip" Knappenberger, assistant director of the Center for the Study of Science at the Libertarian-leaning Cato Institute, which might be philosophically compatible with the Texan.

By phone, Knappenberger said the effects of greenhouse gases on climate change are scientifically proven.

But whether that’s a problem, he said, is "open-ended. If you define all change as a problem, then you have a problem. How much of a problem it is depends on how fast and how large the climate change is that results."

Knappenberger also pointed out articles he wrote in February and March 2013 suggesting fresh research indicates the generally predicted pace of warming may be overstated. "I am not convinced that the pace of global warming is sufficient enough to make greenhouse gas emissions a ‘problem,’" Knappenberger emailed.

Separately, several experts including the Texas state climatologist, John Nielsen-Gammon, told us the scientific consensus is that increases in greenhouse gases, mostly due to burning fossil fuels such as coal and oil, have been contributing to global warming, though the pace of that warming is uncertain.

Naomi Oreskes, a professor of history at the University of California, San Diego, sent us a chapter of a pending book updating her 2004 look into scientific consensus about climate change. A portion of the chapter says: "Scientists predicted a long time ago that increasing greenhouse gas emissions could change the climate, and now there is overwhelming evidence that it is changing the climate." However, "to say that man-made global warming is underway is not the same as agreeing about what will happen in the future. Much of the continuing debate in the scientific community involves the likely rate of future change. "

"There are climate scientists who actively do research in the field but disagree with the consensus position," the chapter later says, "but their number is very, very small."

By phone, Nielsen-Gammon said a helpful indicator of the scientific consensus is the latest assessment of global warming factors, published in 2007 by the International Panel on Climate Change. That body was created in 1988 by the World Meteorological Organization and the United Nations Environmental Programme to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer-reviewed and published scientific literature, Oreskes has noted.

The 2007 report says both that evidence of global warming is "unequivocal" and that 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."

In the United States by itself, Nielsen-Gammon pointed out, the National Research Council, which is among a few independent, nonprofit U.S. institutions that provide science, technology, and health policy advice under a congressional charter, issued an analysis in May 2011. A press release summarizing that work opens: "Warning that the risk of dangerous climate change impacts is growing with every ton of greenhouse gases emitted into the atmosphere, a" council "committee today reiterated the pressing need for substantial action to limit the magnitude of climate change and to prepare to adapt to its impacts."

Separately, an online search led us to a survey of scientists, published in 2009, that initially asked more than 10,000 earth scientists to participate. Among 3,146 respondents asked if they think "human activity is a significant contributing factor in changing mean global temperatures," 82 percent answered affirmatively, with 97 pecent of those respondents with the most climate expertise saying yes.

The article, whose lead author was Peter T. Doran, a professor of earth and environmental sciences at the University of Illinois at Chicago, closes: "It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes. The challenge, rather, appears to be how to effectively communicate this fact to policy makers and to a public that continues to mistakenly perceive debate among scientists."

Similarly, Oreskes said by email, the National Academy of Sciences published the results of a survey of about 900 "actively publishing" climate scientists in 2010, finding that 97 percent of the scientists agreed with the "tenets of anthropogenic climate change," meaning human contributions to warming.

Oreskes told us by email: "The conclusion that humans have contributed to global warming cannot be separated from the role of greenhouse gases  produced by burning fossil fuels. To separate human activities from greenhouse gases is a false dichotomy. Increased greenhouse gases are a direct result of human activities, mainly burning fossil fuels. The scientific conclusion is that ‘most’ of the observed warming of the past 50 years is very likely to be due to the increase in greenhouse gas concentrations, caused by burning fossil fuels. Most of the rest has been caused by deforestation.  Both are human activities, and both are a problem, because they drive adverse impacts like heat waves and droughts."   

A speculation: Perhaps Smith concedes that greenhouse gases contribute to global warming, but maintains that warming itself is not a problem.

Besides, should his claim be laid aside because any definition of "problem" invokes personal judgment?

Scientists see that point, but...

Oreskes said by email: "Of course, the word ‘problem’ is subjective, but insofar as one can say that there is evidence that bears on the issue, the scientific community has amply supplied that evidence." By telephone and email, Katharine Hayhoe, director of the Climate Science Center at  Texas Tech University, said she considers greenhouse gases a very expensive problem because western civilization has been built on the premise of a stable climate. Burning fossil fuels, she said, has fed the greenhouse effect.

Our ruling

Smith said science has not shown greenhouse gases to be a problem.

But scientists have agreed for years that such gases contribute to atmospheric changes driving climatic warming, which is characterized as a global threat.

We considered the idea that the legislator’s reference to greenhouse gases as a "problem" reflects an uncheckable judgment, a matter of opinion. However, our sense is that his statement purported to reflect scientific consensus--and by that yardstick, it is both incorrect and ridiculous.

We rate the claim as Pants on Fire.

Featured Fact-check

Our Sources

Telephone interview, John Nielsen-Gammon, Texas state climatologist, New York, April 19, 2013

Telephone interview, Paul C. "Chip" Knappenberger, assistant director, Center for the Study of Science, Cato Institute, Washington, D.C., April 23, 2013

Report, "Fourth Assessment Report: Climate Change 2007," International Panel on Climate Change, 2007 (accessed April 26, 2013)


Research article, "Expert credibility in climate change," in Proceedings of the National Academy of Sciences, July 6, 2010 (accessed April 26, 2011)

Emails (excerpted), Naomi Oreskes, professor of history, the University of California, San Diego, April 18-19, 2013

Draft article, "Examining the Scientific Consensus on Climate Change," Peter T . Doran and Maggie Kendall Zimmerman, Earth and Environmental Sciences, University of Illinois at Chicago, EOS, Jan. 20, 2009 (downloaded April 26, 2013)

Telephone interview and email, Katharine Hayhoe, director, Climate Science Center, Texas Tech University, Lubbock, April 19, 2013

Browse the Truth-O-Meter

More by W. Gardner Selby

Wayne Smith says science has not shown greenhouse gases to be a problem

Support independent fact-checking.
Become a member!

In a world of wild talk and fake news, help us stand up for the facts.

Sign me up