Arguments
Why climate contrarians are wrong
Posted on 18 December 2015 by Guest Author
This is a re-post from Scientific American
At some point in the history of all scientific theories, only a minority of scientists—or even just one—supported them, before evidence accumulated to the point of general acceptance. The Copernican model, germ theory, the vaccination principle, evolutionary theory, plate tectonics and the big bang theory were all once heretical ideas that became consensus science. How did this happen?
An answer may be found in what 19th-century philosopher of science William Whewell called a “consilience of inductions.” For a theory to be accepted, Whewell argued, it must be based on more than one induction—or a single generalization drawn from specific facts. It must have multiple inductions that converge on one another, independently but in conjunction. “Accordingly the cases in which inductions from classes of facts altogether different have thus jumped together,” he wrote in his 1840 book The Philosophy of the Inductive Sciences, “belong only to the best established theories which the history of science contains.” Call it a “convergence of evidence.”
Consensus science is a phrase often heard today in conjunction with anthropogenic global warming (AGW). Is there a consensus on AGW? There is. The tens of thousands of scientists who belong to the American Association for the Advancement of Science, the American Chemical Society, the American Geophysical Union, the American Medical Association, the American Meteorological Society, the American Physical Society, the Geological Society of America, the U.S. National Academy of Sciences and, most notably, the Intergovernmental Panel on Climate Change all concur that AGW is in fact real. Why?
It is not because of the sheer number of scientists. After all, science is not conducted by poll. As Albert Einstein said in response to a 1931 book skeptical of relativity theory entitled 100 Authors against Einstein, “Why 100? If I were wrong, one would have been enough.” The answer is that there is a convergence of evidence from multiple lines of inquiry—pollen, tree rings, ice cores, corals, glacial and polar ice-cap melt, sea-level rise, ecological shifts, carbon dioxide increases, the unprecedented rate of temperature increase—that all converge to a singular conclusion. AGW doubters point to the occasional anomaly in a particular data set, as if one incongruity gainsays all the other lines of evidence. But that is not how consilience science works. For AGW skeptics to overturn the consensus, they would need to find flaws with all the lines of supportive evidence and show a consistent convergence of evidence toward a different theory that explains the data. (Creationists have the same problem overturning evolutionary theory.) This they have not done.
A 2013 study published in Environmental Research Letters by Australian researchers John Cook, Dana Nuccitelli and their colleagues examined 11,944 climate paper abstracts published from 1991 to 2011. Of those papers that stated a position on AGW, about 97 percent concluded that climate change is real and caused by humans. What about the remaining 3 percent or so of studies? What if they're right? In a 2015 paper published in Theoretical and Applied Climatology, Rasmus Benestad of the Norwegian Meteorological Institute, Nuccitelli and their colleagues examined the 3 percent and found “a number of methodological flaws and a pattern of common mistakes.” That is, instead of the 3 percent of papers converging to a better explanation than that provided by the 97 percent, they failed to converge to anything.
“There is no cohesive, consistent alternative theory to human-caused global warming,” Nuccitelli concluded in an August 25, 2015, commentary in the Guardian.
Thank you for reprinting excerpts of the piece published in Scientific American. It is leading me to reread Whewell.
Unfortunately, the author here seems to me to completely misread Whewell treating his theory of rationality as much less important than it actually is and getting his essential ideas completely wrong. Whewell uses the term 'induction' but it means something other than our usual notion of inductive inference. It's closer to Pierce's notion of abduction.
The author has Whelwell sounding like an old Cartesian – to believe a theory it must be supported by a consilience of inductions. No, – Whelwell's claim is the opposite of this: a consilience of inductions is sufficient to warrant belief in the theory. Consilience is sufficient to verify a theory. Whewell makes a much stronger claim and offers a much more sophisticated analysis of scientific rationality than the author suggests.
But Whewell aside, the author makes a more egregious error. First, I completely accept the fact that we are causing global warming by emitting CO2 into the atmosphere. The evidence is abundant.
The author of this piece seems to conflate the evidence for warming with the evidence of the human cause of this warming.
He cites “multiple lines of inquiry—pollen, tree rings, ice cores, corals, glacial and polar ice-cap melt, sea-level rise, ecological shifts, carbon dioxide increases, the unprecedented rate of temperature increase—that all converge to a singular conclusion.”
But the conclusion is global warming. Only the last two "lines of evidence" i.e., increase in CO2 emission and unprecedented rate of warming are causally related to anthropological global warming.
Certainly the author is right to point to a convergence of evidence for human causation and I believe there is such a convergence. And the author is right in saying that opponents of AGW need to display a convergence of evidence supporting a different, better, and more coherent theory that explains the data.
Opponents of AGW have utterly failed. But so has the author of this piece.
Let me emphasize my position: AGW is well-supported by a convergence of multiple lines of evidence - just not the evidence that the author of the above piece provides.
The author of the above piece shows in the end that he understands the problem. Opponents of AGW have no coherent opposing theory – its the sun, its natural cycles, its cherry picking here and there. This is important
I know that there are many who write for this site that are capable of writing a piece, as eloquent as the one above, excerpted from Scientific American, but do a better job with the science and the evidence for human causation.
In short, is there anything like a Whewellian convergence of evidence showing multiple lines of evidence supporting the theory that that carbon dioxide is causing the warming? I would like to see this narrative better developed than it was here.
Robert Test writes: "Let me emphasize my position: AGW is well-supported by a convergence of multiple lines of evidence - just not the evidence that the author of the above piece provides."
The author of the piece is not actually providing evidence. He is referring to fields of study which have found evidence which undeniably supports AGW, not only from the sources cited by the author of the piece, but also from a host of other sources which all indicate the same conclusion - AGW.
Robert Test needs to insert this denial of validity of the lines of evidence cited by the author, in order to logically construct an argument denying the validity of this evidence as proof of AGW.
As Mr. Test summarizes: "In short, is there anything like a Whewellian convergence of evidence showing multiple lines of evidence supporting the theory that that (sic) carbon dioxide is causing the warming? I would like to see this narrative better developed than it was here."
Mr. Test, did you not say just above this:"First, I completely accept the fact that we are causing global warming by emitting CO2 into the atmosphere. The evidence is abundant."? This is known as circular logic, and such arguments are untenable.
While only 97% to 98% of scientists accept AGW as essentially fact, and the IPCC concensus is that the probability that the warming is human caused is greater than 99% based on dozens of indicators (the vast majority of which are in fact referred to in the most recent IPCC report).
I would just like to iterate here that the author of this piece is not attempting to give an exhaustive analysis of all the underlying lines of evidence used to reach the conclusion that AGW is an undeniable reality, but merely referring to some of the most commonly known indicators which have helped us construct a climate record and allow us to compare our present epoch with prior ones. Perhaps one of the lines of evidence you wished to see referred to here is the carbon isotope analyses wherein the fossil fuel signature is stamped into our modern air? In all but the most theoretical sense, AGW is an undeniable fact, so ipso facto, climate contrarians are wrong.
And we might refer to the work of Dylan, 1968 "You don't need a weatherman to tell which way the wind blows"
criordon,
Thank you for your reply. I appreciate your passion for the topic but
I think you totally misunderstood me. This is my fault. I failed to make myself clear.
I am the type that is more interested in the reasoning and the evidence for one's conclusion than in the conclusion itself. Not that it is important but I accept AGW in that I believe it is a true theory. That AGW is true is not enough. Only reason and evidence warrants our belief that it is true.
So, I am interested in seeing the reasoning and the evidence for that theory layed out as clearly, precisely and eloquently as humanly possible – a Whelwellian narrative displaying the convergence of evidence if you will.
Any such narrative will include a reference to the carbon isotope analysis you mention.
But it will be much more than you acknowledged that the author of the Scientific American piece gave us, namely “some of the most commonly known indicators which have helped us construct a climate record and allow us to compare our present epoch with prior ones."
I don't think it is circular logic to say (1) I believe that multiple lines of evidence for AGW exist and (2) I would like to see an elegantly constructed narrative account of all those multiple lines of evidence.
The Scientific American piece was eloquent in a literary sense but neither philosophically nor scientifically cogent.
I think this website is the place to expect an account that qualifies on all three counts.
Duplicate response removed as per request
robert test,
Perhaps the author including "increasing CO2" but not including "increasing surface temperature" in the list of interrelated apsects investigated is the 'presentation problem'.
Obviously, there is a longer list of areas of investigation that collectively strongly indicate that:
I agree with Robert Test that the writer could have made a much stronger scientific case, but that certainly is some elegant prose
I find the methods of scientific reasoning fascinating, and I confess I don't have a strong opinion as to how much evidence is needed to prove a theory. I do agree that a valid theory is going to have convergent lines of evidence to support it.
But I do take issue with what I perceive as obvious "overstatements," claims of near-unanimity that don't appear to be justified.
Example- The author states: "The tens of thousands of scientists who belong to the American Association for the Advancement of Science, the American Chemical Society, the American Geophysical Union, the American Medical Association, the American Meteorological Society, the American Physical Society, the Geological Society of America, the U.S. National Academy of Sciences and, most notably, the Intergovernmental Panel on Climate Change all concur that AGW is in fact real."
That is preposterous. The author states this is the unanimous opinion of all of the tens of thousands of scientists who belong to those various organizations. I don't have to conduct a poll to know that is not true.
The author also states: "Of those papers that stated a position on AGW, about 97 percent concluded that climate change is real and caused by humans. What about the remaining 3 percent or so of studies?"
What he doesn't mention is highly significant: that roughly 2/3 of the papers examined, and 2/3 of the scientists whose articles were examined, expressed no position on whether AGW is real.
You can't assume agreement from people who expressed no opinion, just like you can't claim 100% support from the members of various organizations that may have taken a public position on AGW.
Most climate scientists may well agree that AGW is real, but that does not mean that there is a consensus amont climate scientists as to how serious an issue it is, or may become, or as to what, if anything can be done, or should be attempted, to deal with it, or as to what other factors may significantly contribute to GW, etc.
In other words, there is still a lot of uncertainty in the science.
robert test @1 and 4, thankyou for your comments.
Let me first note that at SkS we are frequently plagued by deniers (initially) concealing their true beliefs or motives to get the opportunity to present denier memes in the mistaken belief that it will help them avoid moderation (or sometimes, I think, to deliberately court it). That tactic is frustrating for regular commentors because the lack of forthrightness distorts the dicussion, preventing coherent rational response by the deniers. It is also ironic in that forthright presentation would better enable actually escaping moderation.
I mention this because regular commentors do get oversensitized to the possibility of such tactics. As a result they run the risk of inappropriately responding to genuine, forthright enquiry. As a result you may cop some sourness that you do not deserve (although I hope not). I also mention it so I can unequivocally state for my fellow regulars that I do not believe you are flying any false flag here. You raise a valid, and perspicious point.
Your fundamental point is (I believe):
Given that Shermer's enumeration of convergent lines of evidence states that "... there is a convergence of evidence from multiple lines of inquiry—pollen, tree rings, ice cores, corals, glacial and polar ice-cap melt, sea-level rise, ecological shifts, carbon dioxide increases, the unprecedented rate of temperature increase—that all converge to a singular conclusion", your point that it is inadequate, cursory even, is well made. It is, however, unfair.
The reason for that is that the amount of convergent evidence is so extensive that it cannot be adequately summarized in a single page, or article. After all, the IPCC reports are, in part, an attempt to summarize the convergent evidence and it is unreasonable to expect that what takes the IPCC Working Group 1 a volume should be rendered into a few paragraphs.
Shermer is aware of that, and merely points to the fact of convergence in support of AGW vs the wild divergence of theories (let alone evidence) from the skeptics. He hopes that his readers, their eyes opened by Whewell, will notice this fact in the debate and be less prone to be decieved by the skeptics.
If I were to criticize Shermer, it would be on different grounds. Specifically, AGW, they theory that global temperatures are currently rapidly warming and that we are responsible, is really just a corrollary of two more specific theories:
It is these theories supported by the consilience of inductions. AGW is supported by consilience indirectly by these theories, but attempting to enumerate the concilience directly in terms of AGW sometimes obscures the relevance of particular forms of evidence.
For those who want to see the concilience of the evidence, I highly recommend that you read the IPCC AR5 WG1 report, or at least its technical summary. That suffers from the fact that they do not cover some things already comprehensively dealt with in prior reports, so to do it fully through the IPCC you would need to read all reports (or at least the Third Assessment Report forward) and note the differences.
As a less strenuous alternative, I would recommend 'Earth, the operators manual' by Richard Alley, or 'Global Warming, understanding the forecast' by David Archer. I would supplement either by 'The Warming Papers' by David Archer and Raymond Pierrehumbert. I believe (though I have not yet personally audited it), that the MOOC course offered by SkS is also useful in this regard. David Archer has an upcoming MOOC that will, no doubt, also be excellent.
I will not pretend that I can point you to a single webpage that enumerates the conscillience in favour of the concensus position in climate science. I have contributed an enumeration of the evidence that the recent rise in atmospheric CO2 is anthropogenic, and a basic explanation of the greenhouse effect that avoids some common misrepresentations. Unfortunately I never expanded it to anything more comprehensive.
May I suggest that other respondents to robert test point to webpages that expand on those two to provide a more comprehensive enumeration.
PaulG @7, While "You can't assume agreement from people who expressed no opinion", neither can you assume disagreement. Therefore, if no opinion was expressed in a particular abstract, it is statistically irrelevant.
That is not a hard concept to understand in statistics. Routinely political polls of a few hundred people are taken in democracies around the world, and the intentions expressed by that few hundred are projected onto the entire population. Somebody who objected that opinion polls are worthless because "You can't assume agreement from people who expressed no opinion" would merely demonstrate that they have no understanding of statistics (or a strong bias blindsiding them to the implications).
You might object that the 2/3rds were expressing some opinion on global warming, but did not express an opinion on the attribution question, and that is somehow different. But, if they expressed no opinion on attribution, they expressed no opinion on attribution. Similarly, a survey of abstracts in Physics would find about of 65,100 of 1,520,000 papers (possibly including duplicates), ie, roughly 4.3% of papers discuss General Relativity. To suggest that therefore, there is not, or we cannot know that there is a scientific concensus accepting General Relativity would be absurd. The 95% plus of papers not mentioning General Relativity do so simply because they discuss something else. Yet your argument regarding the 97% is equally absurd. The two thirds of papers not expressing an opinion did exactly that. They expressed no opinion on attribution - which is afterall a small part of climate science.
The true question of interest is, out of those papers that expressed an opinion on attribution, including those whose opinion was that attribution was uncertain, how many endorsed the IPCC position on attribution. And the answer to that is, 97%.
Paul @7. There have been various studies and polls of what climate scientists think is causing climate change. Some are less than ideal, however they all show about 95% of climate scientists think we are warming the climate.
I have yet to see a study or poll of climate scientists showing anything remotely different. There is nothing stopping climate sceptics doing a poll of some sort, but they havent published anything.
Do you see where I'm going with this? Im sure you do. Theres obviously a big majority consensus that we are warming the climate. We wont be certain if its exactly 95%, but its big.
I think it is also worth bearing in mind that the article in SciAm is the Skeptic column. It is one page long. The forum does not provide sufficient space to fully argue any topic. Given the narrow contraints, I think that Michael Schermer provided more than sufficient evidence to support his specific premise that the consensus on AGW is a proper scientific consensus derived in a proper scientific way and that the contrarian arguments are neither.
Maybe the SciAm editors can give him the run of a full article with seven or eight pages and he can then dot all i's and cross all t's.
Alun @11, IPCC AR5 WG1 Chapter 8 on Radiative Forcing has approximately 450 references. Excluding the introduction, there are 13 chapters in the WG1 report. There will undoubtedly be overlaps between chapters, but that means there are certainly a thousand, and probably several thousand distinct references use by WG1 all up. You don't compress that to seven or eight pages with any sort of comprehensiveness. You would be doing well to get it down to one 7-8 page article per chapter.
In contrast, it is dubious you would need more than 4 pages to expound in depth any of the alternate 'skeptical' "theories".
9200+ references, Tom, per the WG1 Fact Sheet.
@Robert Test - as a follow-up to Tom Curtis' suggestion (@8) to check out our Denial101x-MOOC, take a look at the first videos of week 1 covering the scientific consensus. You can find the video links in this Full list of videos and references. Also helpful might be the list of accompanying references.
This discussion began with a piece titled Why Climate Sceptics Are Wrong. The piece offers Whewellian multiple lines of induction, and which then moved to a broadly Kuhnian discussion of consensus in the scientific community.
Kuhn said consensus was important in establishing a scientific truth, but he did emphasise other criteria for choosing one scientific theory over another: accuracy, consistency, broad scope, simplicity, and fruitfulness. Popperian falsifiability is implied by Kuhn’s first criterion – accuracy - and falsifiability is still the touchstone of scientific statements. We make observations, create hypotheses, and then try to test the hypothesis to destruction.
The contrarian statement or hypothesis is "The changes to atmospheric greenhouse gases that we humans are causing will not have a serious impact on human well-being in the future."
How is this hypothesis to be falsified?
The first job is to set parameters. What temperature levels will have a "serious impact"?
The consensus (that word again) answer to that question is : +2*C above pre-industrial levels. For the avoidance of quibbling, let us say +3*C.
Is it impossible that continued BAU could not get us up to +3*C?
Because that is what the contrarian hypothesis requires.
Clearly it is not at all impossible for us to get to 3*C. (In fact, we may be booking up for a 3*C experience in 5 or 6 decades' time, unless we do some pretty rapid global decarbonisation.)
Therefore the climate deniers' hypothesis is false.
This is the essence of our case. There are some parts to be filled in, not so much in terms of temperature projections as in the science of attribution, but in examining the deniers' hypothesis and applying falsification to that, the picture becomes much clearer.
For the past few decades, the contrarians have been testing the AGW hypothesis (increasing the GHG composition of the atmosphere will have serious effects on global climate), and the hypothesis remains firm. Now it is time to test their hypothesis.
I dont think there is one contrarian hypothesis. For a huge no. the contrarian hypothesis is "The apparent global warming is caused by scientific fraud". Slightly saner is "The warming some of us are experiencing is due to a natural cycle/natural forcing". The most sophisticated would be "Global warming is happening slowly enough for it to be cheaper to adapt than mitigate".
It is only an argument to have with the rational. Those for whom judgement is based on ideology/identity/values are immune to data-based hypothesis testing anyway. I dont see how you can discuss evidence with someone who blames say, Texas drought, on same-sex marriage laws. How many deniers have you met that took their position on AGW after careful consideration of the science? The more normal bent would be look at AGW as something invented by Al Gore/requiring action incompatible with ideological beliefs/not something my group accepts, and then trawling contrarian sites for things to bolster that predetermined bias.
Scadden, yes I agree that they have an endless number of talking points, each of which has its own implicit hypothesis, and yes, some, for example, Monckton, are way beyond the reach of reason.
Nevertheless, the hypothesis I have identified above covers every other sub-hypothesis, rational or irrational. It is their operational hypothesis: science demands decarbonisation, and their whole effective effort is to block and/or delay decarbonisation.
We need to refute their hypothesis not in the expectation that they will give up and see the light, but in order to demonstrate to uncommitted bystanders, especially journalists and commentators, that their position has no validity. Journalists may not understand the philosophy of science, but they can grasp when a position has been disproven, and it is time for us to demonstrate that this is what has happened to the contrarian's case.
There is a detailed account of falsifiability here http://greenerblog.blogspot.co.uk/2014/10/climate-science-falsifiability.html?m=0
Was plate tectonics theory really resisted by the scientific community? I know Wegener's early 20th century theory of "continental drift" was resisted, but the obvious reason for that resistance was that an explanatory mechanism hadn't been proposed.
1965-68 saw the landmark papers for plate tectonics. By 1976, it was the ruling paradigm. If there was resistance, it was short. Wegner's theory was plain wrong. Yes, the continents did once join together, but they did not travel over the oceanic crust. Plate tectonics was accepted while there was a lot of debate of drivers and mechanism.
Thank you scaddenp. In other words, plate tectonics theory fit the evidence and in about a decade the scientists of the day adjusted their understandings and moved on from there, much as the overwhelming majority of climate scientists and now 195 nations have accepted the reality of climate change induced by human activities.
One modest proposal: Wegener's theory was not 'plain wrong': it was incomplete, sure; imperfect, absolutely; flawed, of course; but clearly not 'plain wrong'. The Wikipedia entry on Wegener links to a 1981 paper by Wolfgang Jacoby with this abstract:
"In his first publication on continental drift, Alfred Wegener anticipated sea-floor spreading, the functional relationship between bathymetry and age or temperature below the sea floor, perhaps mantle convection, and some aspects of plate tectonics. Some of these insights, such as sea-floor spreading and bathymetry with age, did not appear in his later work; others, such as convection and plate tectonics, were taken up when new evidence became available. His intuition led him to these insights, and he had a very clear perception of the distinction between facts and speculation."
It is true that plate tectonics actually did take little time to become the dominant paradigm. However, we should consider that this happened at a time when the means of investigation and the sheer amount of work going into the research made it possible for knowledge to progress that fast.
It took a lot longer for Arthur Holmes to get the geological community on board with the evidence for the true age of the Earth, but partially because he had to wait for the development of the dating methods that could erase all doubt (he also contributed to these developments).
With climate science, we are way past the point where we had to develop the very means of investigation needed to explore the theory. We have everything we need, and more, and there are literally thousands of researchers using the most advanced methods, publishing paper after paper, the immense majority of them pointing in one direction. There is no significant disagreement in the scientific community about the main theory of Earth climate.
PhillippeChantreau @21:
Not quite. For climate investigations, long term observations that encompass a full hemisphere of the Earth would be invaluable. That has recently been obtained for the sunlit side with very much delayed, but recently launched, 'goresat'. The satellite should be paired with an equivalent satellite at the L2 point.
OK Tom, we certainly can refine things. But I have no doubt that we are way past the point where it became evident that long term, sustainable, well being of civilization requires a drastic reduction of CO2 emissions.