The evidence … however properly reached, may always be more or less wrong, the best information being never complete, and the best reasoning being liable to fallacy.”

—Thomas Huxley, Science and Christian Tradition, p. 206

Thomas H. Huxley (1825-1895) was one of the first and most vigorous promoters of modern scientific thinking. He is perhaps best-known as “Darwin’s bulldog”—no one did more to fight for Darwin’s theory of natural selection in the face of theological opposition—but he also almost single-handedly introduced science into the British school curriculum at all levels.

Thomas H. Huxley
Thomas H. Huxley

Huxley was a formidable philosopher of science, anticipating many of the principles of scientific inquiry that Karl Popper would make a mainstay of scientific thinking in the 20th century, including the need for falsifiable hypotheses and non-dogmatic, continuous inquiry.

In short, in the history and philosophy of science, Huxley is someone to be reckoned with.

So what would T.H. Huxley have thought of today’s “consensus” climate scientists, with their claims that the issue of man-made climate change is “settled,” that there is no need for further debate, and that those who challenge the hypothesis of anthropogenic warming in any way are, in effect, heretics?

Three of Huxley’s books—Science and Hebrew Tradition (SHT), Science and Christian Tradition (SCT), and Hume, a biography of Scottish philosopher David Hume (1711-1776)—present Huxley’s philosophy of science very clearly. How well does “consensus” climate science bear up in Huxley’s crucible?

Science is never certain


The pretension to infallibility, by whomsoever made, has done endless mischief; with impartial malignity it has proved a curse, alike to those who have made and it those who have accepted it.

Science and Hebrew Tradition, Preface, p. ix

Just as Huxley fought against religious certainty in his time, so he undoubtedly would have questioned the consensus claim that the evidence for human-driven climate change is “overwhelming” and therefore beyond question.

But, then, orthodoxy always hates criticism, a point Huxley underscored by quoting from David Hume’s “Dialogues Concerning Natural Religion.” In “Dialogues,” Hume has the religious Cleanthes, who believes that because nature is harmonious there must be a Supreme Designer, say to the skeptical Philo:

You [Philo] alone, or almost alone, disturb this general harmony. You state abstruse doubts, cavils, and objections. You ask me what is the cause of this cause? I know not: I care not: that concerns me not. I have found a Deity and here I stop my inquiry. (Hume, p. 178)

Against this view, Huxley wrote: “No man, nor any body of men, is good enough, or wise enough, to dispense with the tonic of criticism” (SCT, “Science and Pseudoscience,” p. 93).

But, of course, the consensus climate science orthodoxy, as expressed many times by believers like Al Gore, Goddard Institute director James Hansen, and Canada’s Andrew Weaver and David Suzuki (who once stormed out of a radio interview because the interviewer dared to suggest the global warming issue is “not totally settled”)(1), is that “abstruse doubts, cavils, and objections” that don’t fit within the consensus paradigm should not be aired lest the public’s faith in anthropogenic global warming be weakened.

For example, in refusing to debate skeptical environmentalist Bjorn Lomborg , Gore said: “We have long since passed the time when we should pretend this is a ‘on the one hand, on the other hand’ issue. It’s not a matter of theory or conjecture.”

Canada’s leading climate computer modeler, Andrew Weaver of the University of Victoria, in explaining his reluctance to publicly debate the question of global warming on a CBC radio program, has written:

There is no such debate in the atmospheric or climate scientific community, and … making the public believe that such a debate exists is precisely the goal of the denial industry. … Scientific debate over global warming would therefore imply uncertainty. (Keeping Our Cool, pp. 22-23)

Why not debate with climate skeptics? Why not crush the abstruse doubts, cavils and objections, as Huxley did many times in publicly debating opponents of Darwin?

For example, in 1860, in one of the most famous debates in the history of science, Huxley demolished the arguments of Anglican Bishop Samuel Wilberforce, who was defending religious doctrine against Darwin’s theory of evolution. Huxley’s attitude wasn’t, like Weaver’s and Gore’s, “I’m right, the other side is wrong, and therefore I don’t need to debate them.” Huxley knew the public needed to hear both sides, not just one, to make up its mind.

For his part, Bishop Wilberforce must have felt he shouldn’t have to defend what he considered immutable religious truth against the upstart scientific heretics. Yet, unlike Weaver, Gore, and most others in the climate consensus, Wilberforce had the courage to publicly debate his views.

Why don’t Gore, Weaver, et al., feel the same need to put their “truths” to the public test? Perhaps because they fear that they and the climate orthodoxy would lose the debate, and quite rightly. The few times warming believers have publicly debated skeptics, the believers have lost.(2,3)

The facts must fit the theory


An inductive hypothesis is said to be demonstrated when the facts are shown to be in entire accordance with it [italics added].

Science and the Hebrew Tradition, “Lectures on Evolution III,” p. 132.

What would Huxley think of the claim that the anthropogenic global warming hypothesis is based on empirical facts (i.e., is an inductive hypothesis), when the facts no longer support (are no longer in “entire accordance with”) that hypothesis? Probably not much given that, despite increasing levels of carbon dioxide in the atmosphere, the planet has not warmed since at least 2001 and perhaps earlier than that.(4)

Theory must account for previous experience


The more a statement of fact conflicts with previous experience,
Figure 1: Temperature and carbon dioxide over 600 million years
Figure 1: Temperature and carbon dioxide over 600 million years
the more complete must be the evidence which is to justify us in believing it.

Hume, p. 158

What is the planet’s “previous experience” in terms of carbon dioxide and temperature? The geological evidence of the past 600 million years shows the relationship between carbon dioxide and temperature is tenuous at best (see Figure 1. The black line is carbon dioxide; the blue line is temperature).

Note particularly 450 million years ago, when the earth’s temperature was as cold as today’s—i.e., the earth was in an Ice Age—while carbon dioxide levels were more than 10 times today’s levels. Clearly, high levels of CO2 weren’t keeping the planet warm then.

There are other periods, such as 100 million years ago, when the temperature remained high but carbon dioxide fell. If, as consensus climate science claims, carbon dioxide is the main driver of climate, why didn’t the temperature start to fall until tens of millions of years after CO2 did?

The consensus view, which closely links high carbon dioxide levels and high temperatures, had no validity in “previous experience” (the geological past). Why should we accept that view now?

Science must be able to predict phenomena


The true mark of a theory is without doubt its ability to predict phenomena.

Science and Hebrew Tradition, “On the Method of Zadig,” p. 20

Huxley didn’t pen these words, although he heartily approved of them. They were written in 1822 by Baron Georges Cuvier (1769-1832), one of the founders of biological classification, and have been repeated by philosophers of science every since.(5) To be valid, a scientific hypothesis must be able to predict phenomena. An hypothesis that can’t make valid predictions is guesswork, not science.

Figure 2: IPCC computer predictions of warming versus real-world temperature data (blue and green lines)
Figure 2: IPCC computer predictions of warming versus real-world temperature data (blue and green lines)

So what would Huxley (much less Cuvier) say of the failure of climate computer models to predict the flat-lining of temperatures over the past decade?

Figure 2 shows the Intergovernmental Panel on Climate Change’s predictions for the next two decades in red, orange and yellow. The blue and green lines show the actual temperatures as measured by Britain’s Hadley Institute and the University of Alabama at Huntsville climate monitoring centres.

Figure 3 shows the predictions of climate alarmist James Hansen in 1988. The blue line is Hansen’s scary Scenario A prediction; the orange line is the actual temperature. The only point of contact between the two is 1998, the year of an unusually strong El Nino warming.

Figure 3: James Hansen's exaggerated prediction
Figure 3: James Hansen's exaggerated prediction

Both predictions—indeed, all of the consensus climate model predictions without exception—have been higher than observed temperatures.

But, then, the IPCC itself said, in its 2001 report: “In climate research and modelling, we should recognize that we are dealing with a coupled non-linear chaotic system, and therefore that the long-term prediction of future climate states is not possible.”(6)

Extreme claims require extreme proof


It is a canon of common sense, to say nothing of science, that the more improbable a supposed occurrence, the more cogent ought to be the evidence in its favor.

Science and the Christian Tradition, “An Episcopal Trilogy,” p. 135

Huxley addressed, a century ago, the question of how much credence we should place in extreme claims of the type that Gore, Hansen, Weaver, and others present as scientific fact.

Not much, if we are also to believe astronomer Carl Sagan, who has written, in the same vein: “Apocalyptic predictions require, to be taken seriously, higher standards of evidence than do assertions on other matters where the stakes are not as great”(7). Sagan’s comment often appears online as “extreme claims require extreme proof,” but Huxley beat him to the punch.

Among these extreme claims is Andrew Weaver’s ominous prediction of a “sixth extinction” that will wipe out “between 40 per cent and 70 per cent of the world’s species” should the global temperature rise above 3.3 degrees Celsius” (a rise that is, for Weaver, entirely humanity’s fault) (Keeping Our Cool, p. 218). He has also called for a complete ban on fossil-fuel use.(8)

Hansen warns of sea level rises of five metres in the next century, 20 metres over the next 400 years (New Scientist, July 25, 2007). And, of course, we should all be familiar with Gore’s apocalyptic predictions (New York under water soon, no Arctic ice by 2014, etc.) if we fail to follow his draconian political and economic program.

Curiously, at least so far, none—not one—of the environmentalists’ apocalyptic predictions, from Thomas Malthus to Paul Ehrlich (mass starvation in the 1970s) to Suzuki, Weaver and Gore, has come to pass.

Or, as the CBC’s Rex Murphy notes:

So much of what the alarmists promised was supposed to be happening now isn’t happening. So many events are running counter to their near-term projections, they’ve decided to go all Armageddon with their long-term ones, projections for a future that none of us will be around to check.(9)

By any standard, the claims of Gore, Weaver, Hansen, et al., are extreme. Yet we are expected to accept these extreme claims with very little public debate, scrutiny, or criticism (after all, the debate is settled and the climate scientists are the experts), and based on almost no empirical evidence (unless mathematical models are considered the equivalent of empirical evidence).

Instead, climate alarmists abandon scientific principles of evidence, fall back on the precautionary principle (if it could happen we must act as if it will happen)(10), and try to silence anyone asking for proof more convincing than the flawed predictions of computer models.

Science doesn’t operate by consensus


My love of my fellow-countrymen has led me to reflect, with dread, on what will happen to them, if any of the laws of nature ever become so unpopular in their eyes, as to be voted down by the transcendent authority of universal suffrage.

Science and Christian Tradition, p. 252

Huxley was worried that citizens would decide to vote against, for example, the laws of gravity. Undoubtedly, he would be equally concerned if scientists declared that a scientific assertion was true because, after a vote, a majority of them had agreed it was so, i.e., proof by “consensus.”

Just as a vote of citizens doesn’t make a scientific fact true or false, neither does a vote of scientists make a fact true or false. Only empirical evidence does that. And the empirical evidence for anthropogenic warming isn’t there.

Dealing with absurdity


When you cannot prove that people are wrong, but only that they are absurd, the best course is to let them alone.

Science and Hebrew Tradition, “On the Method of Zadig,” p. 13

It would be nice to leave the consensus climate alarmists alone. After all, the hypothesis that anthropogenic gases might cause warming is not unreasonable. It may even be true, although so far the evidence (or lack of it) argues otherwise.

What takes consensus climate science into Huxley’s realm of absurdity is the dogmatic insistence that all other hypotheses are not just wrong, but so wrong that they should not be debated or, better yet, not heard at all by the public or other scientists.

Moreover, the consensus climate science alarmists, and their environmentalist supporters, refuse to leave the rest of us alone. Instead, they wish to impose economy-crippling measures based on a global-warming hypothesis that becomes more and more surreal with each year that warming does not occur.


So, how well does consensus climate science meet Huxley’s conditions for real science?

Huxley: Scientific certainty does not exist. Consensus climate science: The evidence is so overwhelming there’s no need to discuss it any further.

Huxley: A strong theory must be “in entire accordance” with the data. Consensus climate science: Ignore data (such as the current cooling) that doesn’t fit the theory (the planet should be warming).

Huxley: Data not in accord with previous experience should be regarded with suspicion. Consensus climate science: Ignore previous experience (such as the geological record showing little correlation between carbon dioxide and temperature) if it doesn’t fit the theory.

Huxley: Theories must be able to predict accurately. Consensus climate science: Nothing, so far, predicted accurately.

Huxley: Extreme claims require extreme proof. Consensus climate science: If the proof doesn’t exist, fall back on the precautionary principle.

Huxley: Science doesn’t operate by consensus. Consensus climate science: Yes, it does.

How, we might wonder, would Huxley fare in a public debate with consensus climate believers like Al Gore, James Hansen, or Andrew Weaver, assuming they had the courage to take him on?

As Bishop Wilberforce discovered, they wouldn’t know what hit them.


1. Barbara Kay, “David Suzuki vs. Michael Crichton.” National Post, Feb. 21, 2007.

2. See, for example, Marc Sheppard’s “No wonder climate extremists refuse to debate” at http://www.americanthinker.com/2009/04/no_wonder_climate_alarmists_re.html. For a list of the few debates that have occurred, and their outcomes, see Climate Depot, http://www.climatedepot.com/a/39/Climate-Depotrsquos-Morano-debates-Global-Warming-with-former-Clinton-Admin-Official-Romm.

3. Losing a debate to skeptic Marc Morano prompted Joe Romm to write, in his blog Climate Progress: “While science and logic are powerful systematic tools for understanding the world, they are no match in the public realm for the 25-century-old art of verbal persuasion: rhetoric.” To say that consensus climate scientists like David Suzuki, Andrew Weaver and James Hansen, much less ex-politician Al Gore, don’t have the rhetorical skills to match the skeptics is absurd. What Romm lacks, what consensus science lacks, and what Bishop Wilberforce lacked, is an argument that makes sense.

4. Meteorologist Richard Lindzen argues that the most recent cycle of global warming ended in 1995. See the Watts Up With That website, http://wattsupwiththat.com/2009/03/30/lindzen-on-negative-climate-feedback.

5. Georges Cuvier, Recherches sur les Ossemens., Paris: Chez G. Dufour et d’Ocagne, Libraires, 1822, p. 292.

6. Intergovernmental Panel on Climate Change, Climate Change 01, Chapter 14, Advancing Our Understanding, Section

7. Carl Sagan, “Nuclear War and Climatic Catastrophe: Some Policy Implications,” Foreign Affairs, Winter 1983/84, pp. 257-258.

8. Andrew Weaver, “‘Environmentalists’ are abandoning science.” Vancouver Sun, March 24, 2009.

9. Rex Murphy, “Armageddon theory: Vancouver,” Globe and Mail, Jan. 10, 2009.

10. For example, environmental writer Jonathan Schell has written: “Now, in a widening sphere of decisions, the costs of error are so exorbitant that we need to act on theory alone. It follows that the reputation of scientific prediction needs to be enhanced” [italics added]. “Our Fragile Earth,” Discover, Oct., 1987, p. 47.

Works Cited

Huxley, T.H., Hume: With Helps to the Study of Berkeley. New York. D. Appleton, 1896.
Huxley, T.H., Science and Christian Tradition. New York, D. Appleton, 1896.
Huxley, T.H., Science and  Hebrew Tradition. New York: D. Appleton, 1896.
Weaver, Andrew, Keeping Our Cool: Canada in a Warming World. Toronto: Viking Canada, 2008.