Global warming consensus exists, and here's why - Daily Inter Lake

In a guest opinion in the Daily Inter Lake, Mark Agather asserts that “… there is no consensus regarding global warming,” referring to it as “an unproven theory.”

On the first count, he is absolutely wrong. The current consensus of more than 97 percent of the scientists who are actively conducting research on this subject and publishing their results in the open, peer-reviewed literature is that global warming is occurring, greenhouse gas emissions from human activities is the primary cause of it, and the climate will continue to warm, posing significant risks to natural and human systems unless these emissions are reduced.

The Academies of Science in 19 countries, including the United States, plus many scientific organizations that study climate science agree with this expert consensus. Further, no national or major scientific organizations or institutions anywhere in the world dispute the reality of man-caused global warming and the risks it poses. If this is the consensus Mr. Agather is referring to as an “unproven theory,” where is the published, peer-reviewed scientific evidence that refutes the theory?  

Agather doesn’t appear to know what a scientific consensus is or how it is arrived at. A scientific consensus is reached at a point in time when the majority of experts in scientific disciplines that study a subject, such as climate, agree on general positions or findings, based on the accumulated body of evidence from research published in the open, peer-reviewed literature. It is these experts who are best qualified to evaluate whether the overall scientific evidence is sufficient to reach a consensus as to whether the evidence supports or refutes a given theory. The consensus can be either an implicitly held position by the majority of scientists involved in the field of study or an explicitly agreed on position. This does not mean that unanimity about the consensus exists among all experts involved in the field of study. It also doesn’t mean that the consensus is definitive and won’t evolve over time as science progresses to further resolve uncertainties.

Agather’s claim about global warming being “an unproven theory” is also mistaken. Science produces evidence that either supports or refutes a theory; it doesn’t ever provide absolute proof of any theory. A theory is considered to be generally “true” when observational evidence collected to test it is found to be consistent with what the theory predicts but is not consistent with the predictions of alternative theories.

In the case of global warming, the observational evidence to date is fully consistent with the theory that human-caused emissions of greenhouse gas are causing global warming. If Mr. Agather doubts this, he should read a series of reports by the U.S. National Academies of Sciences (NAS) entitled “America’s Climate Choices” (http://dels.nas.edu/Report/Americas-Climate-Choices/12781). These reports contain an objective analysis of the existing scientific knowledge on global warming, its cause, and its potential consequences.

One key finding in these reports, which were authored and independently reviewed by climate experts, is that the risks of human-induced global warming “… indicate a pressing need for substantial action to limit the magnitude of climate change and to prepare for adapting to its impacts.” This is a consensus position of climate experts that indiscriminate skeptics and deniers like Mr. Agather refuse to acknowledge and accept.

Agather also makes an unfounded and preposterous claim that a political agenda exists in the community of scientists conducting climate research and that politics is a major part of the science on global warming. He refers to three books as evidence of such an agenda; however none of them contain any such thing evidence. They also contain no credible evidence that refutes the expert consensus on global warming.

lAgather overlooks the fact that all three books were authored and edited by committed and out-spoken deniers of human-caused global warming, and none of the books was subjected to an independent peer review by experts prior to publication. Also, two of the books were authored and edited by employees or advisory board members of conservative think tanks that oppose any regulations to limit greenhouse gas emissions. These same think tanks also published two of the books, and all three books ignore, distort, and misrepresent the substantial body of published scientific evidence that supports the theory on global warming.

Agather also misrepresents and mischaracterizes a statement he quotes from an NAS website as supporting evidence of his claim about politics being a major part of science today, particularly global warming science. The quoted statement is actually about an NAS publication that is a forum for discussion of public policy related to science, engineering, and medicine. Its purpose is to discuss ways to nurture the health of the research enterprise and how knowledge derived from research can be used more effectively to inform the process of public policy making. Surely Mr. Agather doesn’t object to that or believe that relevant scientific knowledge should not be used to inform the policy making process.  

Unfortunately, Mr. Agather simply refuses to be persuaded by facts. His bogus and preposterous claims clearly show that he is clothed in ideological blinders that render him incapable of accepting the legitimate authority of most climate scientists and their expert consensus. Phony and disproven arguments and assertions raised by a small number of individuals who are committed and outspoken deniers of human-induced global warming and its risks is not evidence of a lack of scientific consensus on this issue, and Agather is mistaken to believe that it is.