Climate change denial and motivated reasoning

In his Nov. 3 op-ed in the Inter Lake on “Climate Controversy: Is Global Warming Settled Science or Political Dogma?” Dr. David Myerowitz asserts among other things that “the planet isn’t warming” and that man-made global warming is not a very good theory.

The title of his op-ed reveals his intent is to perpetuate two myths: One is that human-caused global warming is still an open and controversial scientific question, when in fact, it is not. The second is that science on any subject can ever be “settled” in the sense that all uncertainties about every detail can be eliminated, which is both an unrealistic and unreasonable expectation that no area of science can ever expect to meet.

Science deals in the weight of evidence and probabilities, not opinions and speculation. Just because some people disagree with a conclusion that is based on an overwhelming weight of evidence does not mean the science is unsettled. The fact is that almost all climate scientists with expertise and experience on the subject believe, based on the weight of evidence, that global warming observed over the past 60 years is caused largely by humans.

Myerowitz, however, claims there is a “relatively small contribution of man-made global warming” and that “something else is going on.” That “something,” according to him, is “normal cyclical climate changes.” So, if you can follow his arguments, he first believes the climate isn’t warming, then he believes it is warming due to a natural cycle plus a small effect of man-made warming, then believes it isn’t warming, based on his claim that there has been “… no change in global temperature since 1998.” From this contrived and conflicting chain of claims, it’s apparent that he has an aversion to consistent and logical reasoning.

For anyone to hold a belief that the climate isn’t warming and that man-made warming is not a good theory in the face of unequivocal and easily accessible scientific evidence to the contrary is an example of motivated reasoning. Such reasoning is an unconscious tendency for individuals to select and process information that guarantees a conclusion consistent with what they already believe or want to believe. It includes ignoring or refusing to accept the validity of any contrary scientific evidence, and discrediting the validity of such evidence or its sources without any logical or evidentiary justification. It can also include making false assertions, based on “cherry picked” data, misrepresentations and distortions of published evidence, and logical fallacies, under a pretense they are scientifically valid evidence that supports or justifies a belief.

Use of motivated reasoning to deny human-caused climate change is a belief system akin to a superstition but with an end goal; it is not founded on science, logical reasoning, and evidence. Myerowitz’s op-ed demonstrates all of the characteristics of motivated reasoning.

So let’s examine some of his contrived logic and claims in detail. First, if, as he claims, the climate isn’t warming, then he needs to explain why the heat content of the atmosphere, ocean, and land is increasing, why glaciers are retreating almost everywhere in the world, why sea level is rising, why the mass of the Greenland and Antarctic ice sheets is declining, and why the minimum extent of Arctic sea is declining.

Secondly, if it isn’t warming, then claiming that there is a normal cyclical change in climate plus a small contribution of man-made warming is itself a contradiction of that claim.

Thirdly, if the theory of man-made global warming is “not a very good one,” how does he know the contribution of man-made warming is small? The fact is that climate models predict the observed increase in global average temperatures since 1951 only if human-caused climate forcing is included in the models. When the models are forced only with known natural sources, such as changes in solar input, the models fail to accurately predict the observed temperature increase. Fourthly, if there is a “normal cyclical change, then what is his explanation of the mechanism causing the change? Any change in climate is due to a change in the Earth’s energy balance, and saying it’s a “natural cyclical change” is not an explanation of the cause, but instead is a description of a pattern caused by something.

 Myerowitz ignores the fact that his claims are refuted by an extensive body of observational data and evidence assessed in the recently released Intergovernmental Panel on Climate Change 2013 report on the physical science basis of climate change. This report authored by 259 climate experts is an extensive analysis of the current state-of-knowledge about climate change. It is based on results of the latest findings and conclusions of published, peer-reviewed studies conducted by climate experts all over the world.

The evidence cited and discussed in the report all points to the same conclusion: Our entire planet is accumulating heat due to an energy imbalance caused primarily by the rising concentration of CO2 and other greenhouse gases in our atmosphere from fossil fuel combustion and other human activities. Due to this imbalance, the Earth’s climate is warming, resulting in warming of the atmosphere and oceans and changes in many other climate conditions.

The report’s conclusions particularly relevant to Myerowitz’s claims are: 1) “Warming of the climate system is unequivocal, and since the 1950s, many of the changes are unprecedented over decades to millennia.” 2) “It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.” 3) “The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.” (By “extremely likely,” the report’s authors mean 95-100 percent certainty.)

While Myerowitz acknowledges his awareness of this report, which is easily accessible, he ignores its conclusions because they contradict his claims. The only thing he offers to support his bogus claims is more bogus claims. For example, he asserts that there has been “no change in global temperature of our planet since 1998.” The fact is that analyses of surface temperature data, which are collected at thousands of weather stations and on ocean buoys and ships show the global average surface temperature over the land and the oceans has gotten warmer since 1998, and the average decadal surface temperature of the globe has increased every consecutive decade over the past 30 years. All 10 of the warmest years of record beginning in 1850 have occurred since 1997.

While the warming rate since 1998 has been lower than that estimated for the period from 1951 to 2012, a lower rate of increase in global average surface temperature for a decade does not mean global warming stopped in 1998. A recent analysis published in the Quarterly Journal of the Royal Meteorological Society shows that the warming rate of the Earth’s surface over the past 15 years has, in fact, been underestimated due to geographic gaps in surface temperature data in parts of the globe where there are no or very few weather stations, especially the Arctic and Antarctica. When these data gaps are filled using satellite measurements of surface temperatures, which cover the entire globe, the calculated rate of global warming over the last 15 years is more than twice that estimated from data that did not include the filled gaps. Thus, Myerowitz’s claim that the planet hasn’t gotten warmer since 1998 is patently false.

Myerowitz also makes several other false assertions, peddling them as evidence that the climate isn’t warming and that CO2 can’t cause global warming. He also impugns the scientific qualifications and integrity of scientists whose research is the source of evidence that contradict his beliefs by referring to them as “so-called scientists” and “political hacks.” I intend to discuss these and other of his bogus claims in a later letter to the editor.

Jerry W. Elwood, of Kalispell, is the retired director of the Climate Change Research Division in the U.S Department of Energy’s Office of Science.