Climate Change Denial: An Obstacle to Critically Needed Action

February 22, 2022 • Larry Kane

"I used to think the top environmental problems were biodiversity loss, ecosystem collapse and climate change. I thought that with 30 years of good science, we could address those problems. But I was wrong. The top environmental problems are selfishness, greed and apathy...and to deal with those we need a spiritual and cultural transformation."

 Gus Speth, former dean of environmental studies, Yale University

Climate change deniers ("CC deniers"), through their influence on the general public and on federal and state governments, have already caused substantial delay - nearly 45 years - in initiating effective action to extinguish greenhouse gas emissions. This delay has cost humanity the ability to avert a significant increase in global mean surface temperature (GMST). Now, the very best future we can aspire to involves an increase of 1.5°C - or more - in GMST by 2100 over that which prevailed in 1900, based on projections developed by hundreds of climate scientists working under the auspices of the U.N.'s Intergovernmental Panel on Climate Change (IPCC).

Sadly, the reasons for this delay have been, I believe, specious and have lacked strong scientific justification. But rather than asking you to simply accept my conclusions, I propose that we together undertake a clear-eyed review of climate change denialism so that you, our readers, can make your own assessment.

Types of Climate Change Denial

Climate change deniers fall into one of perhaps three categories:

• Those who object to the existence of climate change based on a variety of myths or misunderstandings; i

• Those who pose objections to the reality of man's influence on climate change for reasons that may seem plausible but do not withstand scrutiny; and

• Those who "accept" climate change science in a broad conceptual sense but argue that there is too much uncertainty in the sensitivity of global warming to rising atmospheric levels of carbon dioxide (CO2) to provide meaningful guidance on whether -- or to what extent -- action against climate change is warranted.

Many deniers no doubt rely in good faith on one or more of the foregoing arguments as the basis of their belief. But it also seems probable, as we will see, that some deniers fully understand the reality of climate change and its likely future impacts but nonetheless have asserted one or more of the above contentions as a pretext to obscure their actual ulterior motivations for opposing action against climate change. We will return to this issue further below.

A frequently mentioned example of the first category, as famously expressed by former President Trump, is the assertion, based on a week or two of very cold temperatures in a recent winter, that we are actually experiencing global cooling. This sentiment is founded on a misunderstanding of the difference between (i) short-term, day-to-day weather conditions and (ii) the climate, which describes long-term weather patterns. It is indisputable that annual average global temperatures have been climbing inexorably for many decades, thus describing a change in climate.

An example of the second category involves contentions that the Earth's climate has changed in the distant past due to naturally occurring cycles, such as ancient ice ages and subsequent warming periods, and that the current warming trend is simply another iteration of such natural cycles. However, this frequently offered explanation has been carefully examined by climatologists and their emphatic conclusion is that there is no natural cyclic phenomenon that fits the current data. Instead, the scientific evidence shows the clear "fingerprints" of greenhouse warming induced by human-caused CO2 emissions.

The third, more subtle (and thus more pernicious) approach to CC denial is exemplified by two individuals, Steven Koonin, Ph.D., and Bjorn Lomborg, who each have recently written books lauded by CC deniers. Given the subtle nature of their version of denial, a more detailed review of their explanations will be useful to understanding the bankruptcy of their arguments. As will be seen, both tend to promote similar themes in their climate denial advocacy.

o Steven Koonin

Mr. Koonin, a theoretical physicist, has recently written Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters, a book that promises to "[offer] the truth about climate science that you aren't getting elsewhere," according to Barnes & Noble's advertisement. ii In an August 2021 op-ed piece appearing in the Washington Post and Indianapolis Star belittling widespread concern over future climate change impacts, George Will, a conservative commentator, relied solely on the words of Steven Koonin, Ph.D., including those published in his recent book. iii Unfortunately for Mr. Will, most of the information attributed to Dr. Koonin is outdated, misleading, mistaken, or otherwise irrelevant.

This should not be surprising, given that Dr. Koonin, though a subtle climate denier, is a denier nonetheless. While he gives a nod to climate science, acknowledging that man's combustion of fossil fuels has driven up atmospheric carbon dioxide (CO2) concentrations, Koonin dismisses climate scientists' conclusions that those high CO2 levels have serious adverse impacts, based on his view that such conclusions are plagued with high uncertainty. It is illuminating that Koonin, whose previous work did not involve climate issues, was Chief Scientist at BP (2004-2009). (See subsequent section on actions of the major oil companies, including BP, in lobbying against action to mitigate climate change.)

Koonin's skepticism of projected climate change impacts is primarily based on perceived uncertainties concerning whether human-induced climate change affects hurricanes and other severe weather events. But Koonin's critique is misguided. The most recent (August 2021) climate report by the IPCC - its Sixth Assessment Report -- considers it very likely that high temperature extremes and heatwaves have become more frequent and intense since the 1950s, primarily due to human-induced climate change. iv The IPCC further finds it likely that human-induced climate change is increasing the heavy precipitation resulting from major hurricanes.

Human influences have already caused the average global surface temperature to increase nearly 1.1ºC (~1.95°F) since 1900. The recent IPCC report projects that climate change unquestionably will raise mean global surface temperatures by much higher amounts by 2100, relative to 1900, as illustrated by the following computer-generated scenarios that correspond to varying alternative hypothetical levels of future CO2 emissions:

• 1.5ºC (2.7°F) for a "very low" CO2 emissions scenario;

• 2.7ºC (4.9°F) for an "intermediate" CO2 emissions scenario; and

• 4.4ºC (7.9°F) for a "very high" emissions scenario.

The "very low" emission scenario requires aggressive decarbonization of the energy sector, a strategy contrary to Koonin's recommendations, while the "very high" emission scenario involves weak emissions control and/or substantial expansion in fossil fuel use. The intensity and duration of future heatwaves are projected to increase in proportion to increasing global temperatures.

Koonin utilizes obsolete information in deprecating climate scientists' projections of climate change impacts on the rate of melting of glaciers and polar ice sheets and on the related rate of sea level rise. For example, Koonin states that the rate of sea level rise from melting glaciers has declined slightly and is the same as 50 years ago. He also asserts that melting of the Greenland ice sheet contributes no more to sea level rise than occurred 70 years ago. However, research published in 2020 shows that the rate of ice mass loss from Greenland over 2000-2018 has increased to the highest rate over the past 12,000 years. Projected increases in global temperatures are expected to produce increases in future rates of ice mass loss that considerably exceed the present rate. Also, the IPCC reports that the annual rate of sea level rise averaged over 2006-2018 is roughly triple the average rate for 1901- 1971.

Will's reference from Koonin's book to the Little Ice Age that occurred in Europe during 1450 - 1850 to support the assertion that "science has limited ability to disentangle human and natural influences on climate changes" is wholly misplaced. Human activities in the referenced period would have produced miniscule carbon emissions that would have had no discernible impact on that abnormal phenomenon. Instead, the most likely cause of the Little Ice Age is believed to have been high atmospheric levels of aerosols caused by an extended period of volcanic activity.

In sum, Steven Koonin's flawed arguments utterly fail to dispel the reality of climate change threats.

o Bjorn Lomborg

False Alarm -- How Climate Change Panic Costs Us Trillions, Hurts the Poor, and Fails to Fix the Planet, ("False Alarm"), published in July 2020, is the latest book written by Bjorn Lomborg, a Danish political scientist and a professed skeptic concerning climate change.

This book represents another example of a more subtle form of climate change denial. The author says that he believes in the basic science of climate change, including its anthropogenic origin. However, his affirmation tends to be nominal and may be intended to disarm those who would be inclined to reject his opinions if he openly denied climate change. More specifically, his "denial" is primarily expressed through his inaccurate and misleading minimization of the extent or degree of adverse climate change impacts that should be anticipated if aggressive steps are not taken to reduce CO2 emissions. Lomborg further attempts to indirectly support his "denialism" through (i) his scornful criticism of the efficacy of proposed mitigation efforts and (ii) his exaggerated assessment of the feasibility of addressing climate change impacts through implementation of adaptation measures.

Coupled with Lomborg's subtle denial of significant climate change impacts is a less subtle promotion of fossil fuels, which he sees as the guarantor of future economic growth through its provision of "cheap" energy (as contrasted with "expensive" renewable forms of energy).v His support for this position largely consists of outdated information on the high costs of renewable energy sources that no longer reflects reality. This point is explored further below.

A central theme of Lomborg's book is his perception of an inherent tension between the economic well-being of the world and increasing global warming. "We have to find the right balance" between growing global GDP and rising carbon emissions, he implores. Thus, Lomborg envisions a paradoxical interplay between increasing use of fossil fuels, which he considers essential for the growth of economic wealth, and increasing global temperatures and other derivative climate change damages resulting from increased fossil fuel combustion.

In reality, Lomborg poses a false choice between pursuing prosperity and acting to mitigate the adverse impacts of climate change. He wrongly equates prosperity as dependent on (i) the continued use of "inexpensive" energy derived from fossil fuels and (ii) avoidance of investing excessive monies in what he characterizes as a largely futile effort to mitigate climate change and its impacts. He further errs, as alluded to above, in (iii) his dismissiveness of the adverse impacts posed by worsening climate change, and (iv) his assertion that the adverse climate impacts can be adequately neutralized through measures by which humanity can adapt to those impacts.

The first of Lomborg's errors is revealed through information published in the last eighteen months by entities such as the U.S. Energy Information Administration (EIA), the International Energy Agency (IEA), the World Resources Institute (WRI), and the British government's Department of Business, Energy and Industrial Strategy (BEIS), which show that the cost of electricity generated by utility-scale solar and wind power is now considerably less than that generated by coal combustion and is quite competitive with that generated from the combustion of natural gas.

Concerning the second point, it is likely that greater ultimate prosperity will be realized through robust efforts to arrest the progress of climate change and its multiple adverse impacts. (See the International Monetary Fund's World Economic Outlook 2020.) Moreover, given that there are uncertainties regarding the degree of climate change that may be sufficient to activate tipping points for irreversible, runaway climate phenomena with potentially severe consequences, the more reasonable approach is to tilt the balance toward more aggressive efforts to mitigate climate change.

Lomborg's third error involves his dismissive attitude concerning the serious impacts that climate scientists anticipate from worsening climate change. This attitude appears to derive, at least in part, from his failure to appreciate the significant differences in climate change impacts that can arise from seemingly small differences in mitigation goals. This failure is illustrated, indirectly, by his proposal of a so-called "optimal" carbon tax (a perfunctory effort to reduce climate change impacts). His "optimal tax" would correspond to a scenario involving weak measures to arrest carbon emissions that the IPCC projects would produce an increase in GMST of 3.5°C (6.3°F) over pre-industrial levels by 2100. Yet, the IPCC has projected that climate impacts from a much lower 2°C increase in GMST at 2100 would be significantly worse than those anticipated from its recommended target increase of 1.5°C in GMST, including,e.g.;vi

• a ten times greater likelihood of the absence of summer ice in the Arctic Ocean;

• a 2.6 times greater percentage of global population exposed to severe heat waves;

• from two to three times greater numbers of plant and animal species losing at least half of their current ecosystem range;

• the loss of most coral reefs; and• the loss of an estimated 1.5 million metric tons in annual global catch from marine fisheries.If such significantly worse climate impacts are expected in the event that the increase in GMST over pre-industrial levels were 2.0°C instead of 1.5°C, we have reason to anticipate dramatically worse impacts if the increase in GMST at 2100 were the much higher value of 3.5°C, a situation that Lomborg is willing to accept under his "optimal" scenario.

As his fourth error, Lomborg holds unrealistic views of the ability of adaptation measures and technological innovation to protect the world's populations from future climate change impacts. To illustrate, Lomborg suggests that: (i) all major coastal cities of the world can be protected from rising sea levels by building dikes; (ii) that early warning systems and storm shelters provide adequate protection from increasingly severe hurricanes; and (iii) heat waves (involving higher temperature extremes of more extended duration) can be addressed by more extensive use of air conditioners. However, these adaptation measures are highly unlikely to be adequate for the following reasons: (i) it seems quite questionable, as a matter of technology and economics, that adequate diking could be implemented for all major coastal cities, particularly given that sea level rise under a "business-as-usual" scenario could be in the range of 3 feet or more by 2100 and storm surges can be much higher; (ii) Lomborg's proposed adaptation measures for hurricanes would not prevent property damage; and (iii) even if all impacted populations, including very impoverished ones, could afford air conditioners (which is very doubtful), they would not help people who must work in the outdoors, such as farmers and construction workers. The latter point is especially significant given that projections for a business-as-usual scenario indicate that heatwaves in the range of 115º to 120ºF (which exceed the limits of human tolerance for more than 15 to 30 minutes) could occur for several weeks annually by 2100 in numerous parts of the world.

Two additional ways by which Lomborg attempts to support his underestimation of the impacts of climate change involve what I propose are misapplications of economic concepts. (Lomborg is not a trained economist) One involves his proposed effort to assess the significance of all climate change impacts in stark monetary terms (such as a percentage of global gross domestic product (GDP)). My perception is that Lomborg's reasons for this approach are twofold. One, it allows Lomborg to propose a simple cost/benefit comparison of the costs of implementing a particular plan to mitigate climate change impacts with the costs of climate-related damages that would result if the mitigation plan were not implemented. Two, it results in an undervaluation of adverse climate change impacts since certain impacts are not amenable to a purely economic valuation even though such impacts have critical significance for the sustainability of our existing world and its myriad lifeforms. Such impacts include, e.g., (i) the loss of natural ecosystems, their degree of biodiversity, and the natural benefits they provide, and (ii) the extinction of numerous species of plants and animals.

The other objectionable aspect of Lomborg's economic approach involves his proposed "discounting" of future climate change damages to estimate their "present value" today. A "present value" is obtained through a calculation that is the reverse of the calculation of the future value of a savings account balance that increases exponentially over time due to compound interest. Discounting is often used in a business context to obtain the present values of various proposed investments to provide a common baseline for determining which is the most advantageous. However, discounting the value of future climate change impacts for use in deciding what climate action policy to adopt should be opposed for at least three reasons. One, it relies on the flawed concept discussed above that all climate change impacts can be stated in purely monetary terms. Two, the discounting of climate change impacts that are expected many decades in the future to much lower present values would be likely to create a false perception that such future costs are not particularly significant or worthy of current concern, even though the future impacts are expected to be considerably more severe than present impacts. Three, it raises difficult questions involving intergenerational ethics.

Bottom Line: Lomborg's slanted, misleading book should not considered as a credible basis for discouraging vigorous action against future climate change.

Egregious Deceptions in Climate Change Denial

It may not be well understood that scientists at Exxon Corporation, according to various corporate documents, were aware in the mid-1970s that human-caused emissions of CO2 could exacerbate the natural greenhouse effect so as to raise global temperatures with potentially disastrous consequences. vii A briefing paper on the issue was reportedly presented in 1977 to Exxon's management committee. Another scientist at Exxon was one of the first to develop a computer model to predict the impacts of human-caused climate change. Notwithstanding this internal scientific understanding of climate change, Exxon and many other fossil fuel companies joined in forming the Global Climate Coalition, which promoted the position that the role of greenhouse gases in climate change is not well understood and which aggressively lobbied politicians and the media against taking regulatory or other actions to limit fossil fuel usage. viii Exxon reportedly lobbied the George W. Bush administration to withdraw from the Kyoto Protocol in 2001. ix Reportedly, as of 2019, the largest five oil and gas companies listed on the NYSE spent nearly $200 million a year lobbying to delay or obstruct government policies to mitigate climate change.x


As mentioned at the onset, climate change deniers have exerted powerful influence on the public and on the federal government, engendering such doubt in the science of climate change that initiation of effective action to reduce greenhouse gas emissions -- the primary cause of climate change -- has been delayed by nearly 45 years. The greatest responsibility for this disaster lies with those corporate deniers such as the major oil companies who egregiously promoted disinformation campaigns for decades to sow doubt concerning climate science when their own research reinforced the scientific understanding that fossil fuel combustion was causing global warming.

So, there are two human tragedies building upon each other: the first is that mankind's utilization of the concentrated energy of fossil fuels - considered a great boon of nature - has ironically turned the natural greenhouse effect into an unnatural weapon that is being wielded against man and his world with grievous effect. A second is that, blinded by greed, those who profit most from fossil fuel usage have acted for decades - extending almost to the present day - to deceive their fellow human beings concerning the truth of climate change and the serious threats it poses in order to extend their profiteering as long as possible.

The only valid conclusion concerning this topic is unequivocal: climate denial is intellectually and, in many cases, morally bankrupt and devoid of any defensible foundation. Even the subtle deniers discussed above appear to be continuing to push the same deceptive ploys that corporate fossil fuel companies devised to create and sustain doubt concerning the need to cease fossil fuel combustion. The contentions of CC deniers fly in the face of the accumulating, solid evidence of climate change that is already underway and portends to become much worse, evidence that is strongly accentuated by the IPCC's most recent report of August 2021.

We cannot afford to be deterred any longer. NOW is the time for action.


*iThe Skeptical Science website ( contains an extensive list of climate change myths and objections.

iiBenBella Books, April, 2021;


iv The Sixth Assessment Report of the U.N.'s Intergovernmental Panel on Climate Change, released for public review in August 2021.

v Similar sentiments are expressed by Steven Koonin in his book,Unsettled.

viSeeIPCC's Special Report on Global Warming of 1.5°C, issued in 2018.

viiExxon Knew about Climate Change almost 40 years ago, Scientific American, October 26, 2015;How the oil industry made us doubt climate change, BBC News, September 20, 2020.

viiiIbid; Exxon's Climate Denial History: a Timeline,



Larry Kane