Why Are We Sure We're Right? #1
Posted on 21 April 2012 by Rob Honeycutt
This question struck me while reading a climate change denial website not long ago. The language being used, I thought, seemed eerily similar to language I read on pro-AGW sites. It seemed like a reasonable - and skeptical - notion to explore the idea of why I believe I'm correct when I'm out there on the internet confidently pounding the table over the immediacy of this issue. Why am I sure I'm right? How does anyone reading my words differentiate between what I'm saying and what someone else denying climate change is saying?
I posed this question to the authors at Skeptical Science and the responses have been varied, insightful and engaging. The question itself is provocative and I believe will lead to lots of opinions and discussion.
What I'm going to do is post the responses of several of the SkS authors here and see where the discussion leads us.
First is Dikran Marsupial:
I don't think that we are sure that we are right, as science is never completely settled; we can be confident we are right because the available evidence very strongly supports our position*; however, I sincerely wish that we weren't! It is fundamentally impossible to prove a causal relationship in the real world (only disprove), so it is pointless and misguided to ask for proof of AGW; instead we should follow the advice of David Hume†, who wrote "A wise man propotions his belief to the evidence". In other words we should judge competing hypotheses according to the strength of their evidential support (I would also include the strength, simplicity and coherence of their theoretical justification), but at the same time strive to keep an open mind. The balance of evidence suggests to me that it is highly unlikely (but not impossible) that the skeptics are right and mainstream science is seriously incorrect. There are some things we know with high certainty (for instance that the rise in atmospheric CO2 is purely anthropogenic), there are other things which are only known with substantial levels of uncertainty (such as climate sensitivity). In my opinion, a rational cost-benefit analysis, when all relevant uncertainties are properly taken into account, strongly advocates action to mitigate the effects of AGW, rather than adaption when it is already too late. Sadly it seems that as a species we are currently insufficiently rational, and it saddens me that there will be considerable loss of life and suffering as a result, mostly in the developing world, which has not been substantially responsible for the problem (pro rata) and which is likely to be least able to adapt. However, nothing would please me more than to be proven wrong, as Keynes said "When the facts change, I change my mind. What do you do, sir?", but I will require solid evidence and/or convincing argument rather than rhetoric.
* The links given here are not intended as a complete or systematic survey of the evidence, there are plenty more in the news archive and list of skeptic arguments.† Not only a great philosopher, he could also out-consume Schopenhauer and Hegel.
Next response is from Glenn Tamblyn:
Priority list of data/science, in approximately decreasing order of importance, that would invalidate it - punch holes in enough of these and something meaningful is happening...
1. Our understanding of Quantum Mechanics, Vibrational modes of molecules, Basic Spectroscopy is wrong - write off most of modern technology along with it
2. The 2 1/2 million lines in the HiTran database are wrong in some fundamental way- Wow, thousands of spectroscopists, the US DoD and many others screwed up. And also we don't understand why heat seeking missiles work or Early-Warning Satellites, Airborne Laser systems, weather satellite observations, micro-wave ovens and a whole swag of other stuff.
3. The Radiative Transfer eqn is wrong. Ditto. Plus the Astronomers, Stellar Physicists, Planetologists etc are all idiots.
4. Stellar Physics has it ALL wrong. They don't understand stars AT ALL and the Sun hasn't been warming for 4.5 billion years. And the behaviour of millions of other stars we have studied is all misunderstood. So past CO2 levels actually aren't correlated with past temperatures very well at all.
5. Our understanding of geology, isotope ratio studies, paleontology generally is screwed.
6. 2-3 dozen different Radiative Transfer Codes of varying degrees of sophistication are all wrong - see Spectroscopy, HiTran and the Radiative Transfer Eqn above. BUT they still manage to produce pretty reliable predictions of both the Outgoing and Downwelling Longwave Radiation spectrum, for the whole globe, different latitudes and seasons. Four wrongs miraculously make a right. Serendipity or what?
7. Roger Revelle was wrong (and all the researchers since who have repeated and extended the work). So CO2 actually is taken up rapidly by the oceans. And pH still doesn't change that fast. And Carbonate/BiCarbonate ratios don't change much. Which basically says that an entire branch of Chemistry, dealing with Buffered Chemical Solutions, is all wrong - thousands of related chemical reactions of all types and the entire Chemistry profession don't understand them.
8. Measured heat accumulation in the oceans is totally wrong. Or there is a magical source of heat somewhere here on Earth; that supplies 4 times the available heat flowing out as GeoThermal heat, and that is magically heating the oceans from the top down. And we haven't noticed it.
9. Basic Thermodynamics is wrong. Changing the thermal balance of the planet won't do much to change the temperature. So scratch the First Law of Thermodynamics. This would rank #1 except you need to tackle some of the issues above before this is a factor.
10. The Clausius-Claperon eqn is wrong. So warmer air won't hold more water vapour and thus lead to more warming. Even though we see countless examples of this around us every day - our breath misting up on a cold morning, most of our understanding of refrigeration, air-conditioning etc. And seasonal variations in water vapour content observed from the surface and satellites and their correspondence to seasonal variations in the observed (and predicted) Water vapour component of the Longwave Spectrum are just serendipity - again several wrongs making a right.
11......
Bust a few of these and you have my attention.
And now from Ari Jokimäki:
My first thought on Rob's question is: right about what? But in any case, I don't try to be right about anything. My approach to the climate issues has been to offer people the information about climate science and let them decide themselves if they want to do something about it. People are smart. They are perfectly able to decide what they should do when they have enough information about it. So I spend the time I have for climate science pointing out the research to people. And you know what? Lots of the research is very interesting. If you dig into it, there is a good chance that you will end up digging it.
I usually don't go around making lot of claims about climate, so if I'm right or not is a somewhat irrelevant question to me. However, I do sometimes go around pointing out where some climate related claims are wrong. Those claims are usually made by people calling themselves climate sceptics. They make the claim. I check the existing research relating to the claim. I explain why the claim is wrong. In that I am right because such claims are very often easy to show beyond any reasonable doubt that they are wrong. Even if the science on the issue in question would not be clear, it is easy to see that the claims are wrong because such claims are very often presented with absolute certainty. Curiously, in many cases the same people who present their own claims with absolute certainty, go around saying that climate scientists cannot know anything because things are so uncertain. If uncertainty is their product, how come they are making their claims with certainty?
Rob's question might deal with the fact that there are two apparent sides in climate issue - those who believe that mankind is causing strong changes to climate and those who believe mankind is not causing strong changes to climate. In this picture I would be on the side of those who believe that mankind is causing strong changes to climate. So I guess I should be answering if I'm right in that belief. I don't know. I'm the kind of guy who doesn't care much about theories and models, but I like to look at what observations say. So far the observations I have gotten familiar with are clearly pointing out that mankind is causing strong changes to climate. We of course don't know yet how strong it is going to be, but in my opinion "strong" climate change is already upon us. If we have already changed the climate so much that species are clearly responding to it - and the existing body of knowledge suggests that they are doing so in many ways - then I would say that this is already a strong climate change. Well, actually, strong is rather bad word for it. "Rapid" might be more accurate, because it is the speed of change that is causing harm to the Nature, but unfortunately the strength of climate change is what is usually discussed, or just the amount of warming in many cases.
However, I'm not very happy with this usual two sides scenario. Those who believe and those who don't. Generally those who believe seem to say that we have to do something about the ongoing climate change. I haven't made up my mind on that (there's a lot of reasoning behind this but it's too long a story to include here). So I don't really see myself on either of these sides. I think there are a lot of sides here. There are so many sides that I won't even start listing them. I'll just say that I'm on the side that doesn't want to believe anything and thinks that research results should tell us what's happening and possibly what to do about it, if there is such a need.
We can open these for discussion in the comments section and then move on to part 2 where I'll post my own thoughts and some of the other authors will contribute as well.

Arguments


























How do "skeptics" know that they are right? Well, to put it bluntly, sometimes it is just plain old Dunning-Kruger incompetence (or ideological blindness masquerading as incompetence).
Check out the latest beverage-through-the-nose piece at WUWT.
And don't say that I didn't warn you!!!
"Curiously, in many cases the same people who present their own claims with absolute certainty, go around saying that climate scientists cannot know anything because things are so uncertain. If uncertainty is their product, how come they are making their claims with certainty?"
The highly-certain claims I think are a bit of Dunning-Kruger incompetence, as caerbannog puts it, but it's also used for rhetorical effect. Confident claims repeated many times resonate more among the general public than claims filled with the proper caveats or questions. The former is how politicians usually operate, but at least with politicians, there's some genuine scrutiny of and accountability for their words and actions.
A true skeptic might ask "do climate models project periods of a decade with little warming and if so, what factors might lead to that?", then seek an honest answer. A denier would falsely but confidently assert "climate models predict it will get warmer year over year" but that hasn't happened" then cherry-pick some endpoints on a graph and assert CO2 doesn't cause much warming. Good skeptics are very inquisitive. From my observations, those calling themselves "skeptics" of climate science tend to not be very inquisitive, especially those who lack expertise (D-K Effect again).
The uncertainty card is also played for rhetorical effect. The idea is to cast scientists as being arrogant and overly-confident in their beliefs, not humble and open-minded like skeptics. Another goal is to imply uncertainty means we know next to nothing. But if true, why are the same "skeptics" so confident? There's nothing to worry about, after all, except of course for the costs of mitigation, which will be catastrophic. And so the blatant contradiction.
The two are sometimes combined in some sense. There are those who assert that uncertainty is higher than studies indicate, and those assertions themselves are stated with great certainty. The temperature record is unreliable, the IPCC doesn't appropriately capture uncertainty in climate sensitivity, models have no skill...the "we just don't know" statement carries with it the implicit certain claim that all of the evidence that would indicate otherwise is largely bogus.
Your link certainly threw me straight into a "how do I know I'm right" moment.
You point to an hour-long video posted at WUWT. Do I waste an hour of my life listening to the nonsense spouted by some Aussie Professor dude? The written introduction is as clear as mud. I could examine what the comments say about it, but at WUWT? No thank you!
So why do I dismiss the vodeo as nonsense?
If this Professor is 'right' that CO2 increases are natural, if his theories are more that total nonsense, I will surely meet them again presented in a better way in a better place.
Yet I consider this an unlikely outcome. "Birds of a feather..." The people who accompany village idiots tend also to be of that ilk.
Good to know the estimable Salby is attracting friends at WUWT, as that is a good inverse-ratio indicator of the veracity of his claims.
Salby gave a public talk last year that was greeted with almost complete derision by scientists in the field. Since then he dropped out of sight.
I do not think his musings have made it past peer review. It is not clear if he has even tried. There is a thread about his views here:
Murry Salby confused about the carbon cycle
The Irish comic writer Flann O'Brien has a scientist called de Selby in some of his books. Among de Selby's theories is one that night is caused by a gathering of atmospheric dust. I see a definite relationship.
But claiming certainty about basic physics is not an answer to arguments that point out the uncertainties in climate science. For example, has anyone ever explained why models predicted a stronger polar vortex (less meridional flow) due to lower sea ice, now the models apparently predict a weaker polar jet and more meridional flow (due to lower sea ice). There are plenty of good threads on all of the issues that I have thought about here. That's where the real debate is, everything else is a "smokey back room" debate that does not belong in public.
1. No, its not.
2. Even if it is, it's not our fault.
3. Even if it is our fault, you can't 'prove' it.
4. Why? Because we know it's not.
So there is overwhelming weight of evidence, logical consistency and thought on one side vs. very little beyond stubborn refusal on the other.
Unlike Eric#6, I believe that certainty about basic physics is paramount and must be the focus of the real debate. Our argument stands with basic physics; theirs does not.
Uncertainty about details is the stuff for the 'back room debate'; unfortunately, that is what gets dragged out in public every time there's another spring snowstorm or half-baked idea.
I mean, really... is Anthony Watts still attempting to promote as dead an argument as the idea that the source of CO2 increases in the atmosphere is natural? Really?
He either truly doesn't get that simple, irrefutable fact (in which case the Comments Policy forbids me from saying more on that subject) or else he does know it, and is posting an argument like that any way (in which case the Comments Policy forbids me from saying more on that subject).
In recent months we've seen a number of moderated "yeah, well, maybe, but..." comments from the likes of Spencer, Singer, Pielke Sr. and others. Each of them is trying to to some degree distance themselves from the indefensible, wing-nut, denial claims that make them all look silly (like arguing that the source of the added CO2 in the atmosphere is somehow natural in origin).
They've tried to paint themselves as reasonable moderates in the center of the debate, while certain other factions at the edges are deniers (but no, not them!) or "alarmists." That by itself is silly, but...
The wing-nut element is still there, and they still cling to it when they like, such as Anthony's latest post on CO2 levels, where he has the unmitigated gall to say:
I know why I trust my understanding of the science (which is different from knowing that I'm right), but the question that really intrigues me is...
How do I know they're wrong? Because those in denial of anthropogenically triggered climate change are themselves inconsistent, or rather, they consistently argue the same thoroughly debunked topics. I know they're wrong because they try to score points and engage in propaganda rather than discussing the actual science.
TOP - "certainty," for me, is that level of confidence that allows action to take place in good conscience. I make decisions every day that are based on less than certainty, and I worry about those decisions, but I am forced to act. The level of confidence I have in current mainstream estimates of sensitivity allows me to currently act toward mitigation in good conscience. How someone can, after having looked at the thousands of studies available and the history of the science, come to the confident conclusion that climate science is a hoax baffles me. If John is willing to publicly commit to the idea that "AGW is occurring and that is the absolute, unalterable Truth" then I'll buy a hat and eat it. I suspect he would rather say, "The overwhelming amount of work done by scientists suggests that AGW is occurring, and the suggestion is so strong that I can act as if it is the truth, even if I am still open to the idea that the science may be overturned." Show me a person who claims to have found absolute truth, and I will show you a person who is demonstrably wrong on a regular basis.
So apparently, no he has not seen reason. But any difficulty he has with publishing is purely to do with politics and nothing to do with any flaws in the paper /sarc
At the same time, his failure to explain or even address where human emissions might have gone (if not into the atmosphere and ocean) as well as where the actual increase could come from (given that CO2 has never risen above 300 ppm in the past 800,000 years) is quite simply unacceptable.
His argument amounts to the same denial argument with regard to temperature... an inability to distinguish a trend from the noise. This is basic, basic, basic.
He demonstrates either willful ignorance or complete incompetence. In either case, "excellent" cannot come anywhere into this equation.
Tom @14 - that's disappointing. After not hearing a word from Salby in 8 months I was hoping like Dikran @13 that he had come to his senses. Given his comments on Spencer and Braswell, clearly that's not going to happen.
TOP @11 - I'm sure John would say the point of the handbook is that although we can't be certain, the scientific evidence does overwhelmingly support AGW, and that's what we need to communicate to people.
If Salby's paper appears in a decent journal, there will be comments submitted, even if I have to do write it (again! ;o). I did post Salby a pre-print of my Energy and Fuels paper, but recieved no reply.
See, that's my problem. The more strategically minded deniers seem to have adopted the strategy that they can take and dismiss one, single, ridiculous position that is supported only by the nut-jobs of the world (the slayers), i.e. that the GHG effect violates the laws of physics.
By so doing, they try to imply that they are the center, the denial nut-jobs are on one fringe, and the entire rest of the professional climate science community represents the other fringe.
But they also continue to accept other utterly simple and easily refuted arguments, specifically whether or not the globe is warming (Watts on BEST, Spencer with his recent UHI analysis, Curry with too short a trend) and also -- and this is really, really just downright laughable -- the source of increased carbon dioxide in the atmosphere.
I mean, really... the CO2 arguments are just so basic and simplistic that anyone who tries to go there should have a giant D (let's be nice and say that's for "dunce") branded on their heads... particularly if they are "excellent" scientists like Salby or Curry.
Even Singer refutes the "natural CO2" argument in "Climate Deniers Are Giving Us Skeptics a Bad Name."
I think it's time for scientists who are literally embarrassing the field to be publicly embarrassed themselves.
I mean, it's almost a little too easy for me to accept that I'm right when the most "professional" and "excellent" scientists that are in denial are putting forward insanely stupid arguments (Salby on the source of CO2, Curry on Salby revolutionizing climate science, Spencer on surface UHI when his own work demonstrates the opposite in the troposphere).
Why are we sure we're right?
Because the deniers invest so much energy into coming up with things that are laughably wrong.
2) Why am I sure ? Because I have the math and physics background to understand the argument and the calculations.
3) What would it take to change my mind ? Some process would have to be discovered that masks the warming effect we expect from releasing fossil CO2, together with another process which causes the same amount of warming that we expect from releasing fossil CO2.
I am reminded of "Through the Looking Glass"
"But I was thinking of a plan to dye my whiskers green,
And always use so large a fan, that they could not bee seen"
4) I am certain enough of 1) that I personally waste no time at all on trying to find mechanisms for 3)
sidd
http://mtkass.blogspot.co.nz/2010/10/forget-climate-change.html
And every time that has happened, it is because a different theory explained the data better than the previous one. When plate tectonics was proposed based on continental edge matching, the theory lacked a mechanism. Only when a mechanism (movement of magma, continents floating on that substrate) was proposed did plate tectonics become a viable theory, one that explained those edge matches without arm-waving.
The 'skeptics' appear to be sadly lacking in any such theory. There are lots of half-backed hypotheses through around, most of which are mutually contradictory, and none of which explain the data better than our current physical understanding. In fact, most require ignoring the majority of the evidence - because these hypotheses are incompatible with observations. Glenn Tamblyns list is an excellent start on the range of observations and theoretic domains that new hypotheses must be compatible with.
In the meantime, given the quality of the hypotheses thrown around by the 'skeptics', I am reminded of a particular quote:
"At times one remains faithful to a cause only because its opponents do not cease to be insipid." - F. Nietzsche
Period. Full stop.
I've never met any of you, but I have access to a mass spectrometer, I know how to use it, and I know the implications of measured values and changes and trends in 18O and 16O, 13C and 14C, Hydrogen and Deuterium...and so on...
I can measure them myself. I can do the physics myself. I can repeat the experiments and observations in the classic papers from 150 years ago on forward, and as if by magic, I get the same results they do!! WOW!!
"Consensus" is different from "Scientific Consensus" - "consensus" means we all agree that the Red Sox are the best baseball team and the color green is far superior...
Scientific consensus means that we all can measure similar things, get similar data, show similar trends and that 2+2 = 4.
I know that humans are contributing to atmospheric carbon because I can measure the relative proportions of isotopes of carbon through recent and geologic time... I can measure the change in 13Carbon, and the drop in 14Carbon as older light carbon is added via fossil fuel burning.
I know that 18O is heavier and is preferentially left behind on evaporation and preferentially deposited during the initial rain-outs. That the ice in glaciers is enriched in 16O... that the Oxygen that critters make their shells from reflects the isotopic composition of the extant water they live (and die) in. That their shells therefore reflect changes in 18O/16O ratio, which is a function of the ratio between evaporation, rain-out and glacier melt over space and time.
I can state those as observations, and whether you know me or not, like me or not, think me a complete wanker who stupidly likes the red sox and the color green... you can measure the same thing... and if we're both competent and honest, we will come up with remarkably, magically similar curves through time.
This is well presented in the recent book: CLIMATE CHANGE DENIAL by H. Washington & J. Cook (2011)
TOP, I think is more the point that most of what "skeptics" produce is absolutely wrong. If this was a real scientific debate (with peer-reviewed paper supporting multiple viewpoints), then you would have a valid point. The real science is hardly ever debated.
"I'm on the side that doesn't want to believe anything and thinks that
research results should tell us what's happening and possibly what to
do about it, if there is such a need."
I compare the above with the following:
"I taught you not to believe merely because you have heard, but when
you believed of your consciousness, to act accordingly and abundantly."
- the buddha Gautama
The big problem with understanding climate beyond awareness of
seasons, and differences while travelling, distinguishing it from
weather, is that we are not personally conscious of climate at
any large scale. Yet science extends our senses. Science, as in
climate science cultivates a form of group consciousness. By it we
may "believe of our consciousness" and hopefully "act accordingly
and abundantly"
Noel
"I don't think we are sure that we are right..."
"Right about what?"
"Let people decide if they want to do anything..."
"I haven't made up my mind (we have to do anything about it.."
That's it?
The skeptic side through the Limbaugh's and climatedepot's of the world say definitively that AGW is a HOAX, that scientists who believe it are lying, and that climatology is bought off. Not a lot of equivocation there!
And we are expected to go to battle with "I haven't made up my mind yet...?"
Yikes. No wonder more and more people in this country don't accept the reality of AGW.
"He either truly doesn't get that simple, irrefutable fact ...
or else he does know it, and is posting an argument like that any way ..."
You might value this quote from Plato:
"... there is simple ignorance, which is the source of
lighter offences, and double ignorance, which is accompanied by a
conceit of wisdom; and he who is under the influence of the latter
fancies that he knows all about matters of which he knows nothing.
This second kind of ignorance, when possessed of power and strength,
will be held by the legislator to be the source of great and
monstrous [crimes], but when attended with weakness,
will only result in the errors of children and old men; ..."
Athenian stranger - Plato, Book of Laws, Book IX
Translated by Benjamin Jowett
Noel
Dikran Marsupial said
"In my opinion, a rational cost-benefit analysis, when all relevant
uncertainties are properly taken into account, strongly advocates
action to mitigate the effects of AGW, rather than adaption when it
is already too late."
I would ask a person who raises this matter to use a wooden rule, or
a dressmakers tape, to measure a distance, supposed to be a gap in a
bench say in which a fridge is to go. I would then ask the subject
as to certainty in the measurement. Was it read to the nearest
millimeter? Could it be read more precisely? How accurate is the
instrument of measurement compared to the internationally agreed
standard measure? Has the coefficient of thermal expansion been
considered in the result? Would it be wise to order a fridge to
exactly fit the measurement? What uncertainty should be allowed
for in ordering the fridge? Would you decide not to order a fridge
given these uncertainties, or is your measurement good enough to
act on?
Noel
The consequences of inaction = not having a fridge. Result, spoiled food. The consequences of ordering a fridge that is too large = dealing with the problem while eating fresh and properly cooled food. One consequence is annoying, but tenable... the other is potentially deadly.
On climate: the consequences of mitigating emissions and the atmosphere may be expensive, however the side benefits: cleaner power sources, alternative energy technologies, innovation and the creation and burgeoning of potentially huge markets may well offset any short term annoyances. The consequences of doing nothing are by most measures serious, by many measures dangerous, and by some measures, potentially catastrophic.
The more interesting recent research on this topic has been essentially clipping the long tail of the distribution. In AR4 they stated that sensitivity above 4.5C could not be ruled out, but newer research is starting to rule it out. Which is a very good thing. 4.5C is ominous enough for me. Hell, 3C is pretty darned ominous as well.
1. Relentless attempts to discredit climate scientists or in fact any one who nay says their debating points.
2. Reliance on debating points which are wrong and which they show no inclination to verify for truth.
3. Persistent use of logical fallacies.
4. Cheating and manipulation by a significant number of climate skeptics, particularly the politicals.
5. Consistent promotion of crank science.
6. Lots of arm chair philosophy, but very little science even if you could do the experiments in your kitchen or basement.
If they had a strong position they would not need to do any of that.
If new research were presented that showed us why AGW is not a concern, that some strong negative feedback will prevent higher temps, then so long as it were scientifically sound and withstood the test of proper peer-review, then my "belief" would also change.
At the moment that seems unlikely for both warming and acidification.
Uncertainty however, is not reason for inaction or complacency.
An acquaintance who is a scientist that studied under John Houghton allowed me to question him about the greenhouse effect and AGW. I mentioned skeptics, and looked for his opinion. I had a couple of long chats, and came away with the realization that he had not given me any kind of position at all on the matter, only what he thought were relevant scientific points (Ari's reply in the OP smacks of). I didn't know what he thought about the 'issue'. "Here," I thought at the time, "is a scientist."
(Not long after, one of my (arts) students after 6 months of informal chats in the classroom and pub on climate change, complained I'd said much but given no opinion. I was surprised and pleased as punch - but didn't mistake myself for a scientist :-)
I think skepticalscience treads a line between science and activism. Dikran's response was the one I related to most. His clear concession to uncertainty inspires the most trust in what he might say. Whereas the bald certainty of much 'skeptic' commentary inspires no confidence from me.
I sometimes make the argument that greater uncertainty is actually a greater impetus to do something. If the hazard is potentially lower because we don't know the bounds as well as we thought, that also means (naively) that the hazards are also potentially greater. But this is not a good 'sell' for an activist, because action is encouraged by bold statements, not deference to uncertainty. The irrational 'skeptics' equate uncertainty with lowering the bottom AND top end of the risk scale instead of widening it.
The phenomenon -- in this case climate change -- can only at this stage be explained if we accept greenhouse gas theory. No other explanation can hindcast the data. If someone can offer a credible and testable alternative explanation for the data that has been measured (including the energy balance data, then I would have some doubt. They'd probably also have to show that both GHGs and this other hitherto undiscovered phenomenon exactly affected the radiation in the same bandwidths as GHGs so that both could co-exist without being additive. It's also clear that if there were some other way of explaining the data that, given the enormous interest in maintaining business-as-usal that pretty much every first world government (and quite a few non-first world governments) has -- that someone would have found it by now. Nothing would help them so much as a plausible alternative theory. Yet to dat, they have nothing. Nada.
Given that we have a theory that explains the phenomenon of climate change very well, and no alternative with any credibility, the conclusion is forced. If there were no implications at all for public policy, we might well say "isn't that interesting?" and move on. Of course in that case, the denier movement would be about as active as people who argue that Shakespeare wasn't really the author of Shakespeare's plays.
The problem here is one of equivocation. It is so that one cannot prove causality. There is an inevitable bootstrapping problem. The close association with science of maths inclines people to think that scientific proof must be the same as proof in maths. Of course, it isn't because maths is a closed system with deductive reasoning, whereas science is inductive -- we gather more data and rule out explanations that are not plausible leaving behind what may well be truth.
Science however is mainly focused on utility -- knowledge about the world that is useful to humans. We would like truth, but we accept that even if we get it, we won't be absolutely certain we have it. What we do want from science are useful insights that can steer us away from doing things that are harmful or sub-optimal. Science doesn't need to give us truth in an absolute sense to meet that standard. It only has to give us the best guidance that rigorous observation and inference-making can achieve. For us, that will count as proof because any human response that is based on that will either be optimal, or sub-optimal in ways that reflect the incompleteness of our work or the limits of our technology. We are doing the best we can with what we have.
That is why the objectors to mainstream science are wrong. Of course we can't say with the certainty that attends religious faith that the science as it stands can never be refuted. What we can say is that to reject using what we are very confident is the best explanation for climate change to guide public policy would be a reckless course, on par with ignoring traffic signals on the basis of doubts one had about the consequences of such a course. No court would acquit someone behaving like that on the basis of doubts about the physics and localised impacts of potential collisions.
Stripped of the sophistry, the denier claim is incipiently epistemically nihilistic. If the mere partiality of insight makes insight worthless, then all insight is worthless at least until one can show that it is whole and complete. Of course, by definition, one can't have complete insight save by the route of partial insight first. Nobody could know anything and the "skeptic" case would by their own standards implode into nothingness. If they were consistent, they would joing trappist monasteries and take a vow of silence. Of course they aren't consistent. Nobody outside of a mental institution behaves as if the world isn't knowable -- at least in part.
Every bit of human progress has been built on partial insight, and it will continue to be so. Intrepid humans have tried things out, sometimes to their personal cost but almost always to the beneift of those who could learn both from their triumphs and their failures. We, more than any other species have learned that learning is a good and worthy thing, to stand on the shoulders of those who have shed light where there is darkness and to spurn those who prattle from the margins that we humans are the playthings of fate.
The IPCC-consensus is for mine amply proved to scientific standards. Future science may refine it and make it even more useful as a guide to policy and in the very unlikely event that it is overturned, it will be because someone using the very tools that got us to this point, wielded them even more impressively, not because some self-serving loudmouth did an impression of Mr Horse.
In the real world, data must not only be accurate and salient. To be useful, it must be timely. By timely, we mean that it is available and can be processed in time to inform action. Sometimes, when I'm on hold on the phone, I play a game called "Quadropops". It's a spawning game in which one tries to keep the spawn at bay by continually manipulating the spawn into patterns in which four of the same colour are all in contact. When that occurs, they disappear and any resting on them fall to the next point and if another group of four arises they also vanish. As one accumulates more points, you level up and the spawn comes faster and includes blockers that can only be destroyed by putting one of the four beside them. These two constrain your choice raising the degree of difficulty. By the time you get to level 10 if the spawn have built up much beyond half way, you have no time for careful modelling or the available data. You might have just enough time to work out where things should go but if you take it, they will spawn too early for you to direct them efficiently and you lose control of the game.
The basic point is the value of even salient and accurate data is substantially a function of your ability to deploy it to serve an end. The less time you have to process it and develop responses based on it, the less valuable it is. It would have been better to have had less accurate and less salient data a lot earlier providing the extra time you had allowed you to make better use of it.
In the case of climate change, while there is continuing marginal value in seeking to narrow error bars in areas where uncertainty remains, the reality is that the marginal value in trying to refine the theory before taking action, in areas where uncertainty is for all practical purposes, frivolous, is negative -- and if the current projections are on the optimistic side, perhaps catastrophically so. How much better off would we be going from 95% certainty to 99% certainty, if, while we waited to act, we also became more certain that the previous modelling was excessively optimistic and that we had a chance of foreclosing some of the harm if we'd simply acted earlier? We'd have to conclude with hindisght that our search for ever more impressive certainty had been very costly indeed, even though we now had it.
I do not have the science background to confidently assert that I understand the maths and physics sufficiently to be able to know with certainty on which side the evidence lies.
What I do know is that I can spot where the balance of evidence must lie if one impartially observes the behaviour of the qualified protagonists.
One side has a case that is coherent, consistent, and while it contains gaps, those gaps are acknowledged and are not sufficiently large to justify inaction in such a crucial matter. (Particularly as we must establish a 'post-fossil' economy at some stage, anyway!)
On the other we have quibbling, and a myopic and frequently-selective obsession with uncertainty that, as Fran Barlow points out above, borders on outright nihilism, and is never consistently applied to the remainder of human knowledge in any case.
And that's the strong, merely contrarian, part of the counter-argument.
The bulk of what really is a Denier argument is based, it appears to me, on a single logical fallacy - argument from the undesirable consequences of an idea. AGW implies the Free Market, and all the goodies it showers me with, must be constrained; the Free Market must never be constrained: therefore there can be no AGW. Anyone who says there is is clearly an enemy of the Free Market. And of Freedom.™.
(Frankly, I'm with Žižek - it's easier to imagine the End of the World than the End of Capitalism! In fact, we may yet find out which is more likely! That's why I sincerely hope there are indeed workable market-based solutions to this problem, and why I also cannot understand the marketeers hysterical opposition to implementing them. How heavy-handed are actions deferred until 2030 going to have to be, do you think?)
This results in the egregious conspiratorial nonsense promulgated by the likes of Monckton and Delingpole, which is as risible as anything dished up by the 911 Truthers. And yet these are shining lights in the so called 'skeptic' movement!
The 'skeptic' movement tolerates the most alarming tosh without ever seriously cleaning house of the complete nutters, reverts to the beginning of the argument without warning (e.g. Humans not causing the CO2 increase!), and provides absolutely no coherent counter-narrative. It's hardly likely to, in the circumstances.
In short, it acts, even at its best, like a law firm hired to defend a rich and well-connected white guy called CO2, and then there's the vast and noisy fools' gallery on Fox and the blogs cheering for 'their guy' to get off!
Here are some other truths: If the AGW theory is wrong, we will find out. If the AGW theory is wrong, we'll feel like crap, but we'll accept it, some more quickly than others, but most of us will, eventually.
And the evidence that convinces us of this won't come from flaky blog-posts, pal-review, or the 'tear-up Physics' brigade; it will come from proper, stringent, peer-reviewed, hard-scrabble science.
Because that's the best evidence of anything we'll ever have.
But if you're waiting for 100% certainty before you act, and act decisively, in this matter you really are a fool to yourself and a burden to others. Including - in fact, especially - your own grandchildren...
"AGW implies the Free Market, and all the goodies it showers me with, must be constrained; the Free Market must never be constrained: therefore there can be no AGW. Anyone who says there is is clearly an enemy of the Free Market. And of Freedom.™."
The problem with that statement is that all environmental concerns would fall into that category. In a free market society, there is no other way to protect the environment other than regulation. The reason is that the environment can't be "owned" but rather it is "shared." Typically, when something is shared by a great number of people, care for that thing ends up lacking. Look at public restrooms for example. People leave their mess there thinking someone else will take care of it, or even just have no concern about it in the first place.
Thus, protection of the environment by regulation is essential in a free market system. But we must get it right.
I don't think you are going to get many that would argue "Yes, emitting CO2 is very harmful to the planet, but nevertheless, I have the freedom to emit as much as I please."
These things hurt, and you get lots of resistance, but they don't threaten the core of the beast.
For a start, the Republican Party in the US seems to increasingly believe that regulations, and particularly environmental regulations, have no place in a Free Market economy. And where they go, the rest of the corporate Right (aka 'conservatives', ironically enough) will almost certainly follow; in the Anglo world, anyway.
In fact, this process is already becoming evident here in Australia as the mining industry, and specifically its most reactionary sectors, is beginning to very publicly throw its weight around, with denying AGW as a key focus, and with all the attendant anti-Greenie baggage rolling along behind.
I do think you get many who will say "As long as it is an inherent externality stemming directly from my own affluence I demand the freedom to emit as much CO2 as I please; therefore emitting CO2 is not harmful to the planet. You only want to take my right away because you hate my freedom and envy my affluence."
This is, in my experience, the single most common Denier argument one will encounter on the internet, but cognitive dissonance of course means that they will never state it quite so bluntly. But they do come amazingly close...
PS: You haven't seen all the 'This blog belches carbon' icons? What sort of sociopathy are we talking there?
May I also suggest you read David Michaels' Doubt is Their Product? You may simply have no idea just how many of even the most reasonable - nay, essential - regulationist arguments we have already lost, with virtually no public fanfare...
In my view, being "Right about AGW" begins with the no-brainers which the likes of Lindzen agrees is settled. I then go beyond to dismiss what I see as the falacious assertions of Lindzen on climate sensitivity & the role of natural causes in the temperature record of recent decades.
The final step within the science is to link emissions for likely 'sensitivities' with actual physical impacts (sea level rise, regional/seasonal temperature/rainfall), thus to show at what point Bangladesh drowns or Java melts under the business-as-usual futures. My view on this is far less well founded. I 'believe' that even a sensitivity of 1.5 would lead to unacceptable consiquences, but such a 'belief' does depend on the next step which extends beyond science.
Beyond the science there is the question "So what do we do about it?" and that has attracted just as many crazy & not-so-crazy denialist arguments for doing little or nothing, almost as many as the science has. One big difficulty is that the scientific agruments are now replaced by economic, technological and political arguments which provide a far less disciplined environment for a debate that involves so much uncertainty.
And in explaining 'why I'm sure I'm right' beyond the science is something I'm a lot less practised in.
Thanks for responding. I see your point. But this really frustrates me. The responses are just too theoretical/mathematical/technical...or something like that. This battle is not being waged liked that. We're in a battle for the 'hearts and minds' of the American people (in the US), and the above responses to a question like "Why are we SURE we are Right" just don't cut it. There was no 'surety' at all.
I read something a year ago that a group of scientists were going to be much more active in warning the populace: going on TV and radio, writing articles, etc. Engaging the fight in the media, if you will. In other words, stepping out of their "we just do the study, you decide" mentality.
If the above responses are an indication of that, we're losing. They will not convince anyone, I don't think.
Color me disappointed.
I'm promising myself I _will_ grit my teeth and watch the Q&A, but if I watch the preceding hour of Nick Minchin trying to "change my mind" about climate science I may not have a TV to watch later. He's enough to make me throw stuff.