A survey of 928 papers (published between 1993 and 2003), listed in the ISI Database with the keywords “global climate change” was conducted by Naomi Oreskes. Oreskes found that 97% of climate scientists believed that climate change was from human activity. Over 99% of peer reviewed scientific articles conclude that human-caused climate change is real. As the latest Intergovernmental Panel on Climate Change (IPCC) report (the highly respected and vetted major international effort on evaluating climate change) clearly states: there is no legitimate doubt. There is only a manufactured disinformation campaign build to sustain a fossilised business model at the expense of a habitable earth.

• Myth: Fragments of leaked e-mails between scientists allegedly show that here are discrepancies in the data, or that the numbers showing rising temperatures were somehow altered.

Rebuttal:

Data on climate change is reliable and vast, collected and evaluated by multiple agencies, governments, academic institutions, techniques and scientific disciplines.

The story that the data tells is coherent and cogent.

Data in the real world is sometimes messy; if anything, it is more likely “doctored” when it appears clean and tidy!

Climate is a complex system made of multiple complex subsystems. Certainly, there is more to learn and fine-grained predictions are being refined. Some apparent discrepancies are due to how the data was collected and the purpose of the study, not because it is wrong or misleading.

In any major scientific body of work, data needs to be carefully and critically evaluated, and that is what the peer-review process and looking at the problem from multiple angles does.

Very little in the history of science has been as carefully and intensely peer-reviewed as the IPCC’s reports and findings. It is an extremely conservative institution that rigorously vets its output.

Cherry-picking imperfections or minor discrepancies in the data to imply that the science isn’t reliable is ignorant at best, or disingenuous and purposely misleading at worst.

In 2009, a group of hackers (plausibly originating from either Saudi Arabia or Russia) published fragments of emails between climate scientists at the University of East Anglia onto climate denialist websites. These hackers had searched through their stolen data and combed through it to find attempted to misrepresent the deliberations between scientists as evidence of a nefarious plot (e.g. using the jargon term “trick” to describe a statistical method representing a graph with some proxy data). This was a sophisticated manufactured smear campaign orchestrated among climate deniers. This campaign was designed to stymy progress on regulating CO2 emissions, and ultimately led the scientists to receive a deluge of “stomach-churning” death threats.

This hoax was further publicised around the world (especially in the US), with the aid of many credulous relays in conservative media – among other fervorous defenders of the oil industry.

• Myth: How can we be certain that all the extreme weather effects that you attribute to climate change, like worse hurricanes, droughts and heat waves, wouldn’t have happened anyway?

Rebuttal:

There is a grain of truth in this. Counterfactuals and complex systems can be hard to pin down. Hard, but not impossible. There is a science to attribution. If you are interested in looking at the data yourself: World Weather Attribution reports on attribution of the contribution of climate change on extreme weather events. As they describe themselves on their website: “Extreme Event Attribution was assessed to yield reliable estimates of changing risks of extreme weather by the US National Academy of Sciences. The World Weather Attribution (WWA) initiative, a collaboration between climate scientists at Imperial College London in the UK, KNMI in the Netherlands, IPSL/LSCE in France, Princeton University and NCAR in the US, ETH Zurich in Switzerland, IIT Delhi in India and climate impact specialists at the Red Cross / Red Crescent Climate Centre (RCCC) around the world.”

• Myth: The rise in atmospheric CO2 is secondary to the increase in heat. Correlation is not causation. How do we know that CO2 is the cause of warming rather than a byproduct? Climate scientists have it backwards.

Rebuttal:

There are multiple feedback loops. An increase in heat does indeed increase CO2 in the atmosphere: at higher temperatures, more CO2 is released from natural sources like the ocean, rotting vegetation, and wildfires. Of course, since this phenomenon is the result of rising temperatures, you then have to explain where the higher temperature came from in the first place – and as we have seen above, there is no other credible source. We know the vast majority of increased CO2 and other greenhouse gases (GHGs) in the atmosphere since the beginning of the Industrial Revolution (and particularly since the 1950s post-war economic recovery and expansion) are the direct result of human activity. We have a very good idea of what GHGs we put in the atmosphere and what we measure there!

• Myth: The IPCC and others don’t adequately include clouds in climate models, and miss that clouds will save us.

Rebuttal:

Clouds have long been included in IPCC (and other) models.

Many people, including scientists in other fields, think everything is or should be known, and that just isn’t the case. We are still learning about clouds and climate change. In fact, much of the variability in climate models has long been known to be in large part due to uncertainties about the effects of clouds. There is continued interest in improving our models using supercomputers and new information.

It is true that clouds do modify climate change in many cases by reflecting sunlight (albedo), having a cooling effect, although some reflect less and in some cases result in warming. In fact in 2017, it was indeed estimated that clouds have been a strong modifying factor. This is not news.

It is also true that warming can increase cloud formation: warmer water evaporates more quickly, warmer air holds more water, which itself can increase warming as water vapor is a greenhouse gas, but also increase cloud formation, and many clouds reflect sunlight (some do not). It is a complex system to model.

However, it is just as clear that despite having more to learn, and embracing the idea that clouds do indeed help modify climate change, the models used have been very good at predicting the changes in temperature and other climate change induced problems. The models have been generally correct for over 40 years, including those done by the oil industry! There is no doubt that for over 50 years there has been a trend of increasing global temperatures, melting glaciers and sea ice, warming oceans and demonstrable effects of increased heat on the biosphere, increased extreme weather and wildfires. And critically, the rate of these changes has been increasing. Climate is generally defined in terms of changes that persist for over 30 years.

Clouds are indeed modifying climate change, but they are clearly not sufficient to protect us, and our models reflect that, the need to fine tune our understanding of clouds and our models notwithstanding. The critics are using that critique are using it as a delaying tactic, a smoke screen.

• Myth: The very idea that CO2 can cause global warming is flawed. CO2 isn’t as strong a greenhouse gas as water vapour, which is much more plentiful in the atmosphere, and in any case, the atmospheric CO2 gets “saturated” and couldn’t absorb more heat energy to increase the temperature.

Rebuttal:

This has been debunked a long time ago, but more esoterically-minded climate contrarians will sometimes trot it out. It is very subtle and contains a misconstrued grain of truth.

It is true that the primary GHG is water vapour! But that doesn’t explain the climate change we are seeing now. Water vapour hasn’t changed globally in a way to produce the effects that we are seeing on temperature and the climate. In fact, that would be difficult to do in a relatively short period as water vapour is not mixed in the global atmosphere as rapidly and thoroughly as CO2.

Yes, increased temperature does increase water in the atmosphere, which increases heat trapping. This is a vicious circle. But then, as with the previous “myth”, this is begging the question: where did the increased heat come from to start the process?

This spurious allegation that the saturation of CO2 absorption of infrared radiation (IR, which is heat), could somehow suggest that climate change isn’t the result of increased CO2, draws its origins over a century ago, all the way back to the findings of Svante Arrhenius. Arrhenius was a Swedish scientist who claimed in 1896 that, based on his computations, the use of fossil fuels by humans can increase the global temperature. Arrhenius wasn’t worried; he thought this process would take centuries (though he was writing before cars and planes). Another Swedish scientist, Knut Angstrom, found Arrhenius’ conclusions disagreeable. Angstrom reported in 1901 that, based on what was known at the time, the ability of CO2 to absorb and radiate back heat would eventually reach saturation, and he had an assistant named John Koch do a flawed experiment that he claimed proved this. Even though the measurements he could make were not as precise as we could make now, in fact he DID find an effect! John Koch found when he decreased CO2 concentration in his tube, the mean increase in transmission of IR was about 0.4%. This isn’t far off! That is to say, when there was less CO2, more IR light (heat) passed through, even at the concentrations where CO2 should be saturated in this very artificial experimental situation (if Angstrom had been right). This was a small effect, but one nonetheless.

Why could Angstrom have discounted this change? This appears to have been a case of confirmation bias: Angstrom was more interested in finding confirmation of his pre-existing beliefs, rather than designing a falsifiable and replicable test.

Angstrom’s findings seems to have stalled the pace of discoveries in this relation between CO2 and rising temperatures for three decades, until E.O. Hulburt in 1931 and then G.S. Callendar in 1938 presented new data and calculations.

A related argument that some climate deniers are fond of is the claim that the curve describing how a given amount of heating will result as the CO2 concentration, heating the atmosphere (known as radiative forcing, essentially global warming by GHG interacting with IR) is logarithmic. That means that the curve increases rapidly at low concentrations of CO2, but flattens concentrations of CO2 we have in our atmosphere. The curve flattens, and we are on the flatter part of the curve, and that is why Angstrom’s assistant John Koch found a small effect. The important point is that although the curve flattens, it isn’t totally flat! A good review of this material is found on this article from Skeptical Science: How could global warming accelerate if CO2 is ‘logarithmic’?”

In fact, Angstrom wasn’t totally wrong. The phenomenon of IR radiation saturation of CO2 molecules is real. But it isn’t that simple. Here are some important considerations that explain why CO2 really is the issue (and the same is true of other GHGs):

1.    The model of saturation that Angstrom and modern climate deniers use ignores that the lower atmosphere, the troposphere, where weather happens and the heat radiating to space from Earth is trapped by GHG, warming the globe, isn’t homogenous. It is better modeled as layers that get thinner as you go higher.

In 1908, in response to the recently introduced greenhouse analogy of global warming, the scientist F.W. Very pointed out that we should consider the atmosphere as a system of stacked greenhouses. The atmosphere has layers, and that matters. If a lower layer is saturated, some heat (in the form of infrared radiation) sneaks through the next layer. This next layer is not saturated, so it is heated up, and some sneaks through when that layer is saturated, onto the next layer. Each layer acting like what we would now call a half-silvered mirror, reflecting back some heat energy and yet letting some energy through, and there would be in effect a vast if not infinite amount of these mirrors, capturing more and more infrared light. Angstrom missed this!

2.     There are also multiple absorption bands of CO2 with different sensitivities. It isn’t a simple case that the one band and the infrared radiation (IR) photons have to be exactly the right energy. A molecule like CO2 has a range of IR energies that it can absorb. These bands may be large or small, wide or narrow. When the major absorption band is saturated, there are other, smaller bands of IR light absorption that come into play. Note that some of these bands occur where water vapor is less sensitive to IR, another reason why water vapor isn’t the whole story.

3.     Heat is a measure of molecular motion. The CO2 molecules that absorb an infrared photon increase their energy and bounce around more, hitting other CO2 molecules and energizing them. That means these now more energized CO2 molecules can more easily absorb photons of IR light. So, there is a small effect of essentially decreased saturation (which is really an increased ability to absorb photons), a feedback loop called “pressure broadening.” We can conclude that saturation is a dynamic phenomenon! 

4.     The atmosphere is colder and becomes thin (there are less gas molecules of all types, including water vapour and CO2) the higher you go. CO2 is better mixed higher up than water molecules, so CO2 has more of an effect.

At high altitudes, the air thins out and is cold, and most of the infrared radiation (heat) at that level is lost to space without being absorbed and so does not participate in radiative forcing (it slips through the cracks). That is called the emission height (EH); the air temperature at this height determines the rate at which heat leaves the atmosphere. Increased GHG like CO2 elevates the EH. That is, there is more gas, the atmosphere is less thin, and more GHG means more heat is re-radiated from higher in the atmosphere and so less escapes to space. So now more radiation at this slightly higher EH is trapped. Doubling CO2 raises the EH 150 meters. This is a relatively small effect, yet it is enough to raise the temperature sufficiently to alter our biosphere and ability to survive and thrive as humans.

Some say the elevated EH is the most important reason more CO2 increases global warming. Here is another way of explaining it, as written by American physicist Spencer Weart:

“What happens if we add more carbon dioxide? In the layers so high and thin that much of the heat radiation from lower down slips through, adding more greenhouse gas molecules means the layer will absorb more of the rays. So the place from which most of the heat energy finally leaves the Earth will shift to higher layers. Those are colder layers, so they do not radiate heat as well. The planet as a whole is now taking in more energy than it radiates (which is in fact our current situation). As the higher levels radiate some of the excess downwards, all the lower levels down to the surface warm up. The imbalance must continue until the high levels get hot enough to radiate as much energy back out as the planet is receiving. Any saturation at lower levels would not change this, since it is the layers from which radiation does escape that determine the planet’s heat balance.”

Another brief explanation of this phenomenon that appropriately centers on EH, from the Skeptical Science website:

“In summary, the science is sound, theoretically, mathematically and experimentally. What may have been reasonable objections well over a century ago have been debunked. The most common way they try to frame things is to claim that IR emitted from the surface, in the wavelengths where CO2 absorbs, is all absorbed fairly close to the surface. Therefore, the story continues, adding more CO2 can’t make any more difference. This is inaccurate through omission, because either innocently or deliberately, it ignores the rest of the picture, where energy is constantly being exchanged with other molecules by collisions and CO2 is constantly emitting IR radiation. This means that there is always IR radiation being emitted upwards by CO2 at all levels in the atmosphere.

When you include all the energy transfers related to the CO2 absorption of IR radiation, then we find that adding CO2 to our current atmosphere acts to inhibit the transfer of radiative energy throughout that atmosphere and, ultimately, into space. This will lead to additional warming until the amount of energy being lost to space matches what is being received. This is precisely what is happening.”

• Myth: I have heard of some scientists who disagree, which means the science must be up for grabs. Furthermore, climate science isn’t actually real science, it is only science by consensus and modelling rather than verifiable experiments.

Rebuttal:

There is a consensus: very few scientists disagree that climate change is real and caused by human activities.

One figure often quoted is from Naomi Oreskes’ 2004 paper: in their publications between 1993 and 2003, 97% of climate scientists agreed with the consensus that climate change is due to human activity, but that was several years ago. More recent estimates (in 2021) place the figure at over 99%!

But then, the climate contrarians have a point: science isn’t a matter of voting! Perhaps these deniers think that the lone rogue scientists who disagree are true visionaries who have overcome the climate cabal’s censorship. But what is leading them to think this?

If we take a look at these dissenting voices in the scientific community, we usually find that these are professional deniers for hire: this was the case of the prominent Willie Soon, who was paid over 1.5 dollars from the fossil fuel industry between 2005 and 2015, in exchange for laundering their propaganda through his scientific reputation. Willie Soon never disclosed this obvious conflict of interest, though he produced many “deliverables” for these oil companies in the form of scientific articles casting doubt on anthropogenic climate change. This was a clear violation of the trust of the academic journals who published his misleading works for hire. Willie Soon and his acolytes pocketed cash from companies such as Koch Industries and Exxon to manufacture the appearance of a scientific debate, when they were in fact just working as lackeys to provide a veneer of acceptability of denialism on behalf of their corporate masters.

These so-called “experts” have unabashedly lied and cheated. This is well documented, as evidenced in our bibliography at the bottom of this page.

This is important because even though the science of climate change is clear, as we have seen, some scientists continue to deny that human activity is responsible for climate change. It has been documented time and time again that many were doing it for money, though some may be motivated by ideological belief in unfettered unregulated enterprise… motives can sometimes be difficult to ascribe. In any case, the record shows that oil executives have chosen to allocated massive sums to money to protecting their business interests by purchasing political speech. There is no organised lobby on the climate side to counter the American Petroleum Institute. The countervailing force is scientific rigor. These moneyed interests are redirecting their subsidised oil profits to distort science through a very expensive propaganda effort. They use the money that the government gifts them through massive subsidies and funnel it into obscurantist campaigns.

One recent example of a prominent scientist denier is John F. Clauser, who has won the Nobel Prize in physics (which gives him some legitimacy as a scientist, but of course the Nobel Prize has been also given for climate scientists). He decried that climate change is formed by consensus. This is a red herring, given that essentially all science is in part formed by consensus and being refined. He also made many comments that ran counter to all known atmospheric science, even at the most basic level.

What appears as a consensus that may reflect a lack of good science is really due to the nature of the systems involved. Climate is complex, with local and global feedback loops that cannot be replicated in the laboratory. Physics, chemistry, geology, astrophysics, oceanography, ecology, meteorology, earth systems, geography, human institutions (politics, sociology, demographics the economy), all play a role in understanding the processes involved and making predictions about what will happen, and how we can and will and should respond to the changes.

We are in uncharted territory, with huge numbers of interactions that are constantly changing. It is not as precise as, say, a physics experiment that is highly contrived and set up to answer a specific question as Clauser, for example, seems to demand. It is not possible to do nice, compact laboratory experiments for many of the complex concerns about the climate and earth systems. So, yes, there is a need for consensus and modelling in climate science which is as complex as systems get.

The main point: when you run into an outlier, in this case a scientist who is bucking the 99% who believe climate change is real and due to human activity, dig a bit deeper.

It turns out that In May 2023, Clauser joined the board of the CO2 Coalition, a climate change denial organization. It is a right-wing front group funded by the oil baron Koch brothers in part, and headed by a former CEO of the American Petroleum Institute. That doesn’t mean that Clauser is wrong, but scientists are always expected to present potential conflicts of interest in any presentation, because we are human and our biases do matter. Maybe Clauser joined that group because he was tired of climate scientists being wrong, but that is a very specific choice that clearly reflects a bias, and possibly corruption. He could have objected in less polarizing ways if he didn’t share the oil funded right-wing group’s bias and philosophy. Whether Clauser made these errors due to ignorance, arrogance or bias, his claims around consensus are not in good faith and can be easily rebuffed.

There are many legitimate refinements to be made about climate science and the effects of global warming and climate change, as well as real issues of how our solutions can be achieved with justice. But we have to be smart about it, and not let ourselves be bamboozled by greedy actors sowing doubt.

Stay vigilant!

Bibliography for deeper reading about where these myths come from:

Merchants Of Doubt, how a handful of scientists obscured the truth on issues from tobacco smoke to climate change. Naomi Oreskes, Erik M Conway. Bloomsbury Publishing, 2019 (published originally 2010). There is the reasonable questioning of science, it is part of the territory. Then there is dark money, greed and obfuscation. We saw all this before, with pollution and cigarettes, for example. Lying for money, even when it causes pain and death, is not new to climate change!  What some will do for money and power never ceases to amaze.

The New Climate War, the fight to take back the climate. Michael E Mann. Hachette Book Group, 2021. A long but well-researched book by a top climate scientist.

The Petroleum Papers. Geoff Dembicki. GreystoneBooks, 2022. A history of disinformation, lies and manipulation by the oil companies with a starring role for Koch industries told by a journalist.

The Parrot and the Igloo; Climate and the Science of Denial. David Lipsky. W.W. Norton and Company, 2023. A bit idiosyncratic in style, but a colorful and insightful look at the topic of denial and the bad guys with eye-opening stories.

Saving Us; a climate scientist’s case for hope and healing in a divided world. Katharine Hayhoe. One Signal Publisher (Simon and Schuster), 2021. This book has some good information about responding to climate deniers.

About the oil companies’ disinformation campaigns:

This article in The Conversation presents a summary of what the oil companies knew going back 50 years. Exxon made some excellent predictions. In January 2023, the journal Science published an article assessing ExxonMobil’s internal projections from the 1970s about the destructive effects of their incessant CO2 emissions.

We did a deep dive on this topic of the oil industry’s obfuscation for an episode of our podcast titled “Gaslighting (#ExxonKnew)”, which is also available with illustrations on YouTube, as well as an episode focused on how to talk to conservatives about climate issues.

The podcast Climate Deniers Playbook does deep dives into one specific misconception or argument of climate denial per each episode, in order to derisively deconstruct their fallacious arguments.