Published by on 17 Apr 2009 at 08:21 am
Consensus climate science: What would Thomas Huxley say?
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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.
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
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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
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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
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The more a statement of fact conflicts with previous experience, 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
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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.
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.
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
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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
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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
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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.
Conclusion
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.
Notes
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 14.2.2.2.
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.
Bob Webster on 18 Apr 2009 at 4:15 am #
Paul,
A brilliantly constructed presentation of the foolishness of the “the debate is over” crowd. Ironically, what peeves them the most is that both public and scientific opinion has rapidly been shifting over the past several years as global climate cools. No surprise people are cool to their warming theory.
One would think that if the AGW crowd were composed of intellectually honest people, they would be strongly motivated to debate their position with any critics to stop their loss of public support. Evidently, they believe they’ve got politicians so much in their corner, that public support isn’t necessary.
They are all in for a very rude awakening. Any short term political victories will be overturned as reality and the cost of senseless carbon mitigation schemes become apparent.
Great piece!
Rolf Hopkinson on 22 Apr 2009 at 9:26 am #
Hi Paul,
Thanks for a well researched and carefully crafted article. A wake-up call if ever there was one to those who have been blinded to the naked body of the emperor in his ‘new clothes.’
Rolf
John on 24 Apr 2009 at 1:51 pm #
Excellent piece on why everyone should be skeptical of everything. One interesting tidbit of of information I hadn’t really taken note of before is the IPCC quote: “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.” I have been looking to see what a “coupled non-linear chaotic system” is. Overall I think this is a mathematical concept.
The reason I ask is that what little I have found leads me to believe that you would expect such a system would oscillate. Since chaotic implies noise then the noise would be reinforced into oscillations until overwhelmed by some other phenomenon. I do know that there are many periodic planetary weather related systems such as the Pacific Decadal Oscillation (PDO) which is “primarily a geographic rearrangement in atmospheric and oceanic circulation patterns in the North Pacific that last about 30 years” (Spencer: http://www.drroyspencer.com/research-articles/global-warming-as-a-natural-response/ ).
So the question is: does the IPCC description of the climate as a “coupled non-linear chaotic system” mean, by definition, such a system should oscillate? Or, stated differently: would such a system not varying be an unexpected result?
Nate on 12 May 2009 at 4:17 pm #
Paul,
I’m in California and I’m literally SURROUNDED by Global Warming Alarmists, but I for one have dared to question them. I’ve been called a tree-killer, a Democrat-hater, an un-intelligent nitwit, and many other things. I have written a speech and 4 papers on the subject, so I am not just throwing myself in a dangerous position for no reason. I am glad to see the number of people who question the facts of the Alarmists’ is growing. One final fact to leave on here: I am only in the 8th grade.
Michael on 03 Jun 2009 at 2:24 am #
“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.”
Regarding the Ordovician Period, I don’t believe that it presents the problem that you believe it does. The matter isn’t as simple as, “according to greenhouse theory, Earth should have been exceedingly hot then.” One of the issues to consider is the fact that most of the world’s landmass was gathered at the South pole in a supercontinent known as Gondwanaland. Having the majority of the land at one of the poles allows for glaciation events even with higher carbon dioxide concentrations. Climate models showed this result back in 1999 [1]. Also of interest is the fact that the Appalachian mountains were just being created, exposing a large amount of easily weathered silicate rock to the atmosphere (which would have acted to take down atmospheric carbon), coinciding with the start of the Late Ordovician glaciation.
I’ll try to respond to a few more of your questions when I have some more time.
[1] Poussart, P. F., A. J. Weaver, and C. R. Barnes (1999), Late Ordovician Glaciation Under High Atmospheric CO2: A Coupled Model Analysis, Paleoceanography, 14(4), 542–55
Paul MacRae on 03 Jun 2009 at 3:53 pm #
Michael,
Thank you for an intelligent and informed comment. In a way, though, I think you’re making the point I want to make: other factors aside from CO2 drive the climate. In the case of the our ice age, the Pleistocene, for example: we wouldn’t have these cycles of glaciation, despite falling CO2 levels, if it wasn’t for the circumpolar current around Antarctica and the joining of North and South America, plus the upraising of the Himalyas and Rockies much earlier which, quite apart from leaching CO2, also disrupted warm air currents, especially in Asia.
In other words, at least in my view and based on the evidence I’ve seen, CO2 plays a much smaller role in climate than many other natural factors, including those you mention–the IPCC models set the sensitivity of climate to CO2 much too high.
Paul
Michael on 07 Jun 2009 at 2:55 am #
“Thank you for an intelligent and informed comment.”
You’re welcome. Thanks for the response. I’ll try to answer a few more of the questions that you have raised—though there’s a lot here, so I’m not going to attempt to address it all in a blog comment. If there’s anything that you think that I’ve missed that you’d really like answered, I don’t mean to dodge it—just point it out and I’ll get back with a reply as soon as I can.
I’ll begin with the points on which I believe we will agree and move on from there.
“Science doesn’t operate by consensus.”
While I agree with this statement on its face, I think that we need to be cautious in discussing this. NOAA’s Robert Grumbine makes a good point when he says: “[s]ometimes people are right about a statement and then draw the wrong conclusion about it. Noting that science doesn’t ‘do’ consensus is such a case.”* So, I want to be careful not to draw the wrong conclusion here. I’ll outline and flesh out Grumbine’s points as follows: Science hasn’t progressed through people simply, without reference to data or theory, agreeing on something and declaring it fact by consensus. There is the area of “live” science, with constant research, and either confirmation or refutation—and there is the area of accumulated, well-tested scientific knowledge. Once some particular theory (or observation, or what have you) has been confirmed many times over (perhaps by the falsification and research program paradigms envisioned by Popper or Lakatos, if you like) there is the overall agreement of the community on it and it gets added to the body of scientific knowledge, and as such has the general consensus of the community. The key point though, is that it didn’t get there through mere consensus, it was tested over and over again and must continue to fit with the facts as they come in (here is where I anticipate that we would begin to disagree regarding global warming).
“other factors aside from CO2 drive the climate”
The climate system definitely has other drivers, or forcings, aside from carbon dioxide. On this point, we’re all agreed. These range from other greenhouse gases, such as methane, to various aerosols, fluctuations in solar irradiation and land use changes. See, for example Hansen’s paper in Science [1].
There are two fairly important related points, the first of which is that—at least, to the best of my knowledge—there isn’t one climate driver that explains changes in climate over all time scales. No research scientists that I’m aware of make this claim. There are many factors that need to be considered for each case, from Milankovitch cycles to plate tectonics. The second point is that, once the effects of all of the natural forcings are taken into consideration, they do not account for the recent warming trend—whereas, once the anthropogenic emission of carbon dioxide is taken into account, the warming trend is quite clear [1], even on a continental scale [2].
“the IPCC models set the sensitivity of climate to CO2 much too high”
Why is it that you say this? I know that there are several different ways of going about calculating climate sensitivity (Rahmstorf outlines these here [3]): one could look at the ice core record, factor in everything from dust to methane concentrations and perform a correlation analysis; one could use radiative forcing, take into account the relative strengths of the various feedbacks (essentially, Arrhenius’ method) or one could use model results. To the best of my knowledge, these methods have tended to lead to a climate sensitivity in the stated IPCC range (3º ± 1.5 º) [3]. As far as I can tell, the best estimate of 3º hasn’t changed much since Manabe’s work in the 1970s.
“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?”
This is a good question. I’m guessing that he would point out—if he were informed about the reasons for choosing a 30 year period for climate when discussing global temperature: ENSO events, the PDO, etc.—that the models are meant to predict climate on the scale of 30 years, not the fluctuations on a smaller time scale. So, I would guess that he’d caution all involved about doing this. He might also look into the spread of the simulations [4], to determine which models fit better than others and determine why that was. He might discuss to what degree the lack of fit was due to the models failing to capture ENSO events, etc. (which would average out over those time scales with which a discussion of climate is concerned).
“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.”
Regarding this, Huxley might first ask what the forcings were in Hansen’s report and double-check that the scenario being compared matches the forcings. Upon seeing that the forcings from this period more closely match Hansen’s scenario B, he might ask why the A scenario was being compared against the observations in the first place, when the forcings more closely match that of (and hence, it makes more sense to compare the observations to) the B scenario [5]. Following this, he might ask to see the results of the B scenario [6].
Huxley was an observant fellow, so he would probably ask to view the associated uncertainty due to natural fluctuations. After looking at this he might comment that, while the observations fit into the lower bound of the uncertainty and while this might be acceptable for results on computers less powerful than a modern netbook, there was certainly room for improvement (improvement that, largely, has come with present GCMs).
“Why not debate with climate skeptics? Why not crush the abstruse doubts, cavils and objections”
I think that, first of all, it should be said that there are several roads that can be taken in terms of addressing doubts and objections, only one of which is public debate (which I’ll address next). One such path is clear communication of, and access to, the science for the general public. The public does need clear access to the relevant findings with a minimum—and an explanation of—technical jargon, freed of excessive caveats, as well as the cited science (i.e. without having it locked behind subscription “pay walls”). Here, I think that the IPCC reports as well as work on the parts of researchers such as Hansen, Weaver, Rahmstorf, the Real Climate guys and organizations such as NOAA, GISS, etc. are really making a difference.
As regards debate, I think that Dr. Weaver makes two good points above: the first, when he states that there is no such debate in the peer reviewed scientific research journals (e.g. Journal of Climate, Geophysical Research Letters, etc.). The second, when he points out that it is the goal of the denial industry to make it seem as though there is a raging debate in the scientific community. For, as long as there is debate, there is excuse for inaction.
A point which is not made in the quote above, is the difficulty that people have in sorting out scientific arguments outside of the area of their expertise. For instance, in an online debate, Phillip Stott implies that global cooling was the consensus of the scientific community during the 1970s[7], when in fact, during the period of 1965-1979, 7 papers suggested cooling, 20 were neutral and 44 predicted warming [8]. This is hardly a consensus for cooling. But, to anyone unfamiliar with the literature, this isn’t clear. More, even if Schmidt calls Stott on this fact, the public is left with Stott’s word against Schmidt’s: two PhD scientists. (Of course, they can always go back and look at the material, but they can only do so after the debate.)
With that said, certain climate scientists, such as Gavin Schmidt, do choose to debate from time to time [7].
One last question: given that you work at UVic, have you discussed your questions with any of the climate scientists there or at the CCCMA?
* http://moregrumbinescience.blogspot.com/2008/12/science-and-consensus.html
[1] Hansen, J., et al. Earth’s energy imbalance: Confirmation and implications. Science, 308, 1431-1435
Online, in full: http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf
[2] Here, the black line is the observed temperature trend, blue is the models with only natural forcings and pink is the models with anthropogenic greenhouse gas emissions considered (taken from the IPCC AR4, WG1 contribution): http://i.fe.imwx.com/web/fe/2008/07/aussie3.jpg
[3] See, for instance, pages 39 through 42 of Rahmstorf’s paper here: http://www.pik-potsdam.de/~stefan/Publications/Book_chapters/Rahmstorf_Zedillo_2008.pdf
Or, alternatively, for line-by-line radiative transfer models, see here:
http://pubs.giss.nasa.gov/docs/2006/2006_Collins_etal.pdf
[4] Models “baselined” to:
1999: http://www.realclimate.org/images/2008_from1999.jpg
1990: http://www.realclimate.org/images/2008_from1990.jpg
1979: http://www.realclimate.org/images/2008_from1979.jpg
[5] http://cce.890m.com/hansen88/images/forcings.jpg
[6] http://cce.890m.com/hansen88/images/scenarios-observations.jpg
[7] http://www.youtube.com/watch?v=KtPDuZzfzhw&feature=related
[8] http://ams.confex.com/ams/pdfpapers/131047.pdf