Facts and myths about climate change (Gettysburg Times op-ed)

Many lines of scientific evidence confirm that our planet is warming because humans have put greenhouse gases like carbon dioxide into the atmosphere by burning fossil fuels. Measurements taken with various instruments on satellites, airplanes, ground stations, and ocean buoys over many years and continuing now show that less heat is escaping into space because carbon dioxide molecules absorb the escaping heat energy in the same way that the glass of a greenhouse traps heat. The upper atmosphere is cooling while the lower atmosphere is warming, a distinct signature of greenhouse gas warming.

Further, computer models of atmospheric and ocean circulation are all clear about the longer-term deleterious effects on the climate of this greenhouse gas warming, even if the details vary.

Yet, despite the overwhelming evidence of human-caused climate change, there is still a whole lot of denialism and misinformation about climate change that is published in this newspaper in letters to the editor and op-ed columns. The myths these writers spread suffer from one or more of five categories of fallacies. My column today is meant to help you spot these fallacies.

One of the more common categories of fallacies is quoting fake experts. Science, like many other human endeavors, is sufficiently complicated that no one person can gain expertise in every area of science. You certainly would not call a skilled electrician when your house is flooded by a plumbing failure. Before you accept as gospel what your buddy down the street who has a science Ph.D. tells you about climate change, check that he/she has expertise in climate science, as evidenced by a record of publication in peer-reviewed science journals. The fake-experts category of fallacy also includes mistaking scientists’ arguing with each other over the interpretation of a particular data point or a particular modeling result to mean that there is “debate” in the scientific community over the reality of human-caused global warming and climate change when, in fact, there is no such debate.

Most climate change myths suffer from one of the multiple forms of logical fallacy. One of the most common I have seen is the “single cause” fallacy. It goes something like this: the climate has been undergoing cycles of change throughout Earth’s history, so the current period of warming is natural and not human caused. This fallacy can be likened to the person who comes across a murder victim and, before conducting any investigation, concludes that the death is from natural causes because most humans throughout history died of natural causes.

Other forms of logical fallacy include ad hominem arguments, where attacks are made against the person presenting the evidence for climate change rather than addressing the evidence itself. One recent letter writer, for example, dismissed climate change by complaining that advocates for action on climate change are bullies. Another form of logical fallacy is misrepresentation, where a fact is mis-stated or distorted in such a way as to make it easier to knock down. Another common logical fallacy is raising a “red herring” by deliberately diverting attention to an irrelevant fact to distract us from the much more relevant facts. In an op-ed published on Sept. 20 and in a Letter to the Editor published on Sept. 6, the writers made much ado about the fact that carbon dioxide is good for plants and agriculture, claiming on this basis that climate change is not harmful. This claim is the classic “red herring,” in that it distracts us from the much more relevant fact that the carbon dioxide molecule traps heat radiating from the Earth’s surface because that heat energy is transformed into numerous modes of the molecule’s energy of motion. Furthermore, their claim that increased carbon dioxide makes up such a small fraction of the atmosphere that we do not have to worry about it is yet another “red herring” for the same reason.

A third category of fallacies is impossible expectations, in which the climate change skeptics demand unrealistic standards of certainty. Science does depend on a process of skeptical inquiry, and no scientist will assert a scientific fact with absolute certainty. Science, however, does not need absolute certainty to advance understanding. This concept is very difficult for non-scientists to understand or accept. The claim that climate change science is false because it cannot be proven with absolute certainty suffers from the fallacy of impossible expectations.

The fourth category is “cherry picking.” Here the climate change denier will pick out the one bit of information that supports the preconceived bias, or relate an anecdotal story instead of relying on good arguments and compelling evidence. An example of this fallacy goes something like this: the climate change denier will point to the fact that last January in one particular location was the coldest January in a decade, so global warming is not happening. The fallacy here is to confuse short-term variability (weather) for long-term trend (climate).

The fifth category of fallacy, conspiracy theories, is the most pernicious. The conspiracy theorist makes claims, without evidence, that climate scientists and everyone else who advocates for action to mitigate the deleterious effects of climate change, are cooperating with each other with nefarious intent to act against the public good, or to destroy the economy or our way of life. This fallacy is pernicious because attempts to present evidence that the conspiracy is false are taken by the conspiracist as further evidence of the conspiracy. How do you tell when someone is engaging in conspiracy theories? Just look for the word “hoax.” The Sept. 20 op-ed contains this word no fewer than eight times. This alone disqualifies it as a credible source of climate change information.

Now that you know the various categories of fallacious thinking, I invite you, dear reader, to look critically at future op-eds and letters from climate change deniers, and find the fallacies for yourself.

Jeff Colvin is a research physicist and co-chair of Gettysburg DFA. He lives in Gettysburg. The opinions expressed herein are his own.