What is a climate denier?

Climate change denier, climate denial and similar terms peaked in usage, according to Google trends data, at the last presidential election. Usage today is well below those levels, but based on trends in the last week, is heading for a new high. The obvious meaning of climate change denial would seem to me to be saying that either the climate is not changing or that people are not responsible for climate change. But this is clearly not the case.

Patrick Moore, a once influential Greenpeace member, is often called a denier by climate activists. Niall Ferguson says he doesn’t deny anthropogenic climate change, but is attacked as a denier. After a Long Now Foundation talk by Saul Griffith, I heard Saul being accused being a denier. Even centenarian James Lovelock, the originator of Gaia theory who now believes his former position was alarmist (“I’ve grown up a bit since then“), is called a denier in California green energy events, despite his very explicit denial of being a denier.

Trying to look logically at the spectrum of propositions one might affirm or deny, I come up with the following possible claims. You can no doubt fine-tune these or make them more granular.

  1. The earth’s climate is changing (typically, average temperature is increasing.
  2. The earth’s average temperature has increased more rapidly since the industrial revolution.
  3. Some increase in warming rate is caused by human activity.
  4. The increase in warming rate is overwhelmingly due to humans (as opposed to, e.g. sun activity and orbital factors)
  5. Anthropogenic warming poses imminent threat to human life on earth.
  6. The status quo (greenhouse gas production) will result in human extinction.
  7. The status quo poses significant threat (even existential threat) and the proposed renewables policy will mitigate it.
  8. Nuclear energy is not an acceptable means of reducing greenhouse gas production.

No one with a command of high school math and English could deny claim 1. Nearly everything is changing at some level. We can argue about what constitutes significant change. That’s a matter of definition, of meaning, and of values.

Claim 2 is arguable. It depends on having a good bit of data. We can argue about data sufficiency, accuracy and interpretation of the noisy data.

Claim 3 relies much more on theory (to establishing causation) than on meaning/definitions and facts/measurements, as is the case with 1 and 2. Claim 4 is a strong version of claim 3, requiring much more scientific analysis and theorizing.

While informed by claims 1-4, Claims 5 and 6 (imminent threat, certain doom) are mostly outside the strict realm of science. They differ on the severity of the threat; and they rely of risk modeling, engineering feasibility analyses, and economics. For example, could we afford to pay for the mitigations that could reverse the effects of continued greenhouse gas release, and is geoengineering feasible? Claim 6 is held by Greta Thunberg (“we are in the beginning of a mass extinction”). Al Gore seems somewhere between 5 and 6.

Claim 7 (renewables can cure climate change) is the belief held by followers of the New Green Deal.

While unrelated to the factual (whether true or false) components of claims 1-4 and the normative components of claims 5-7, claim 8 (fission not an option) seems to be closely aligned with claim 6. Vocal supporters of 6 tend to be proponents of 8. Their connection seems to be on ideological grounds. It seems logically impossible to reconcile holding claims 6 and 8 simultaneously. I.e., neither the probability nor severity components of nuclear risk can exceed claim 6’s probability (certainty) and severity (extinction). Yet they are closely tied. Naomi Oreskes accused James Hansen of being a denier because he endorsed nuclear power.

Beliefs about the claims need not be binary. For each claim, one could hold belief in a range from certitude to slightly possible, as well as unknown or unknowable. Fred Singer, for example, accepts that CO2 alters the climate, but allows that its effect could be cooling rather than warming. Singer’s uncertainty stems from his perception that the empirical data does not jibe with global-warming theory. It’s not that he’s  lukewarm; he finds the question presently unknowable. This is a form of denial (see Freedman and McKibben below) green activists, blissfully free of epistemic humility and doubt, find particularly insidious.

Back to the question of what counts as a denier. I once naively thought that “climate change denier” applies only to claims 1-4. After all, the obvious literal meaning of the words would apply only to claims 1 and 2. We can add 3 and 4 if we allow that those using the term climate denier use it as a short form of “anthopogenic climate-change denier.”

Clearly, this is not the popular usage, however. I am regularly called a denier at green-tech events for arguing against claim 7 (renewables as cure). Whether anthopogenic climate change exists, regardless of the size of the threat, wind and solar cannot power a society anything like the one we live in. I’m an engineer, I specialized in thermodynamics and energy conversion, that’s my argument, and I’m happy to debate it.

Green activists’ insistence that we hold claim 8 (no fission) to be certain, in my view, calls their program and motivations into question, for reasons including the above mentioned logical incompatibility of claims 6 and 8 (certain extinction without change, but fission is to dangerous).

I’ve rarely heard anyone deny claims 1-3 (climate change exists and humans play a role). Not even Marc Morano denies these. I don’t think any of our kids, indoctrinated into green policy at school, have any idea that those they’re taught are deniers do not deny climate change.

In the last year I’ve seen a slight increase in professional scientists who deny claim 4 (overwhelmingly human cause), but the majority of scientists in relevant fields seem to agree with claim 4. Patrick Moore, Caleb Rossiter, Roger A. Pielke and Don Easterbrook seem to deny claim 4. Leighton Steward denies it on the grounds that climate change is the cause of rising CO2 levels, not its effect.

Some of the key targets of climate activism don’t appear to deny the basic claims of climate change. Among these are Judith Curry, Richard Tol, Ivar Giaever, Roy Spencer, Robert M Carter, Denis Rancourt, Richard Tol, John Theon, Scott Armstrong, Patrick Michaels, Will Happer and Philip Stott. Anthony Watts and Matt Ridley are very explicit about accepting claim 4 (mostly human-caused) but denying claims 5 and 6 (significant threat or extinction).  William M. Briggs called himself a climate denier, but meant by it that the concept of climate, as understood by most people, is itself invalid.

More and more people who disagree with the greens’ proposed policy implementation are labeled deniers (as Oreskes calling Hansen a denier because he supports fission). Andrew Freedman seemed to implicitly acknowledge the expanding use of the denier label in a recent Mashable piece, in which he warned of some green opponents who were moving “from outright climate denial to a more subtle, insidious and risky form.” Bill McKibben, particularly immune to the nuances of scientific method and rational argument, called “renewables denial” “at least as ugly” as climate denial.

Opponents argue that the green movement is a religious cult. Arguing over matters of definition has limited value, but greens are prone to apocalyptic rants that would make Jonathan Edwards blush, focus on sin and redemption, condemnation of heresy, and attempts to legislate right behavior. Last week The Conversation said it was banning not only climate denial but “climate skepticism”). I was amused at an aspect of the religiosity of the greens in both Freedman and McKibben’s complaints.: each is insisting that being partially sinful warrants more condemnation than committing the larger sin.

So because you are lukewarm, and neither hot nor cold, I will spit you out of My mouth. – Revelation 3:16 (NAS)

Refusal to debate crackpots is understandable, but Michael Mann’s refusal to debate “deniers” (he refused even to share his data when order to do so by British Columbia Supreme Court) looks increasingly like fear of engaging worthy opponents – through means other than suing them.

On his liberal use of the “denier” accusation, the below snippet provides some levity. In a house committee session Mann denies calling anyone a denier and says he’s been misrepresented. Judith Curry (the denier) responds “it’s in your written testimony.” On page 6 of Mann’s testimony, he says “climate science denier Judith Curry” adding that “I use the term carefully.”

I deny claims 6 through 8. The threat is not existential; renewables won’t fix it; and fission can.

Follow this proud denier on twitter.




  1. #1 by Larry Robert on September 25, 2019 - 9:39 pm

    Hey Willie – so what is it that 97% of scientists agree about? That’s the figure that Gore always cites. Obama reported it during his reign. NASA used the 97% number. I know what you think of NASA’s integrity from your Challenger talk.

  2. #2 by False Progress on September 26, 2019 - 10:14 pm

    “Claim 2 is arguable. It depends on having a good bit of data. We can argue about data sufficiency, accuracy and interpretation of the noisy data.”

    No, that’s just your opinion based on vague assertions, and, without proving its validity, you try to strengthen it below. Tons of logical fallacies in the post, jumping from one conclusion to another with an obvious agenda. Funny how nobody had a beef with CO2 as a heat-trapping gas until big money was threatened.

    “Claim 3 relies much more on theory (to establishing causation) than on meaning/definitions and facts/measurements, as is the case with 1 and 2. Claim 4 is a strong version of claim 3, requiring much more scientific analysis and theorizing.”

    I’d like to see “skeptics” explain why the thing they like to call a “trace gas” is the only thing keeping Earth from being too cold to inhabit, and why Man’s road to doubling it from a baseline of 280 ppm is something they go out of their way to trivialize. That’s why they’re called deniers!

    Also, I think James Lovelock is dissed by some Greens because he dared speak against ugly industrial wind power, along with the normally dishonest likes of Trump. Point being, there’s denial on both sides, but Man is definitely mucking up the planet on many levels.

    • #3 by Bill Storage on September 26, 2019 - 11:17 pm

      By “claim 2 is arguable” I mean it is literally arguable; it can be argued. Its truth depends on data. The integrity of the data has been argued. E.g. there have at least 4 downward revisions of older temperature data that has the effect of increasing the apparent rate of upward change. There may be valid reasons for those revisions. People argue about revisions to effects of el nino impact in data from 40 years ago. So no, it is not a closed case. By “arguable” I don’t mean that I necessarily dispute the motivations for that revision, but one needs to make a case for it. It’s not self evident.

      Why quote “skeptics”? Are they not skeptical? Is Patrick Moore a pawn of big oil? Is Philip Stott in Trump’s pocket?

  3. #4 by hallhere (@hallhere) on September 29, 2019 - 11:16 am

    Sobering…Chernobyl on HBO

  4. #5 by hallhere (@hallhere) on September 29, 2019 - 11:30 am

    (glancing at the AMBASSADOR)
    If I can speak freely, sir — look, these guys
    talk big, but frankly, we think they’re short of
    know-how. You can’t just take a bunch of ignorant
    peasants and expect them to understand a machine
    like one of our boys, and I don’t mean that as an
    insult, Mister Ambassador. Hell, we all know what
    kind of guts your people have. Why just look how
    many millions of ’em those Nazis
    (pronounced NAZZEES)
    killed and, hell, they still wouldn’t quit.

  5. #6 by Bill Storage on September 29, 2019 - 8:26 pm

    “Well, I’ve been to one world fair, a picnic, and a rodeo, and that’s the stupidest thing I ever heard come over a set of earphones.”

  6. #7 by hallhere (@hallhere) on September 30, 2019 - 3:25 pm

    Really look at #4 above, it is scary what those peasants did with a very “sporty” nuclear plant.

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