Can “the Big Cutoff” Settle the Science?

Even if we grant the dubious proposition that there is a "consensus" in the scientific community that AGW is real and significant, there is certainly nothing remotely resembling a consensus on the following crucial empirical questions:

1. How much of the warming is due to human activities vs. natural variability. The IPCC "consensus" is merely that the warming is "primarily" anthropogenic. But is that 51%, 70%, 95% or what? It matters greatly.

2. How much additional warming will occur by a given future date under various emission scenarios. This is primarily a matter of the huge uncertainty surrounding "climate sensitivity."

3. The physical effects of a given level of warming on sea levels, ecosystems, agriculture, water resources, and so on.

4. The nature and magnitude of the costs and benefits of a given level of warming.

The answers to these questions are crucial to policy choices, but the "science is settled" crowd rarely pays them any serious attention, preferring to dwell on worst-case-scenario predictions to try and build support for their predetermined policy agenda.

Even if there is no genuine scientific uncertainty around the existence of AGW, there is lots of uncertainty about how bad it will be.

But I just heard Gavin Schmidt from GISS and RealClimate just admit that there was huge uncertainty. The e-mails clearly show uncertainty.

But so what? What matters is risk mitigation. We should spend $1 if and only if the expected value of the mitigated risk is greater than or equal to $1, with suitable discounts for risk aversion and time preference. We would have done the right thing even if ex post it turns out we wouldn't have suffered the damage.

Correct. That is the problem with the AGW side. It cannot justify the spending because none of the proposals will do anything to combat warming even if they were right about CO2 emissions.

Even if there is no genuine scientific uncertainty around the existence of AGW, there is lots of uncertainty about how bad it will be.

But so what? What matters is risk mitigation. We should spend $1 if and only if the expected value of the mitigated risk is greater than or equal to $1, with suitable discounts for risk aversion and time preference. We would have done the right thing even if ex post it turns out we wouldn't have suffered the damage.

Since I can't really believe Will doesn't understand this, I wonder about his good faith on the subject.

A lot of readers may be interested to learn that the science on smoking and lung cancer isn't "settled" either:

Lindzen clearly relishes the role of naysayer. He’ll even expound on how weakly lung cancer is linked to cigarette smoking.

Also, lots of scientists, including tenured biologists, disagree about this evolution business. So I guess that's out.

It's so hard to come by secure knowledge these days.

Not to be rude, but the evolution analogy is weak.

1) Evolution theory has been around a lot longer. This doesn't invalidate the analogy, but it still matters.

2) Evolution theory is tautologically true unless you assume an intelligent designer. In other words, the only alternative hypothesis to Evolution Theory is "god did it". While this may be a valid claim for some, it is most certainly NOT a scientific claim, nor a falsifiable one. With climate change, on the other hand, the alternative hypothesis to AGW theory is natural variation/low sensitivity. Actually there are many alternatives to AGW theory, but all of them make valid and testable scientific claims. The fact that there are quack biologists who believe in intelligent design has absolutely no relevance to the fact that there are climate scientist who think that natural variation with low climate sensitivity is a better model.

Not to be rude, but the evolution analogy is weak.

1) Evolution theory has been around a lot longer. This doesn't invalidate the analogy, but it still matters.

2) Evolution theory is tautologically true unless you assume an intelligent designer. In other words, the only alternative hypothesis to Evolution Theory is "god did it". While this may be a valid claim for some, it is most certainly NOT a scientific claim, nor a falsifiable one. With climate change, on the other hand, the alternative hypothesis to AGW theory is natural variation/low sensitivity. Actually there are many alternatives to AGW theory, but all of them make valid and testable scientific claims. The fact that there are quack biologists who believe in intelligent design has absolutely no relevance to the fact that there are climate scientist who think that natural variation with low climate sensitivity is a better model.

Someone should ask Singer about the ozone hole, too.

That's the kind of guy libertarian think-tanks tend to hire as "senior fellow".

To imply that consensus is not identical to absolute unanimity is to savagely beat the English language with a lead pipe and leave it for dead in an alley.

I am nothing if not savage.

Also Michael, it's pretty obvious that, vis a vis Will, you're not one of, y'know, those contemporaries. Will is communing with Truth here, and nothing you say can prevent him from getting away with it.

It seems irrefutable that the earth is warming. Even if it is the case that the science isn't settled, let's consider two scenarios; man isn't the main cause of global warming but we curb emissions anyway, or man is the cause of global warming but we don't curb emissions. The the first scenario will probably be detrimental to the global economy but, the latter I believe is the far more dangerous prospect. Considering the rate at which the earth seems to be heating up and the implications of that process, I don't think we can sit around and wait for the science to be settled.

John Derbyshire (a good science journalist despite his rather creepy views on some others subjects) made what I think is an interesting comment about this. When the science is not completely settled, there will be contrarians, and the will be people who are inside the system (eg., Lindzen). When it is completely settled, there will still be contrarians, but they will be outside the system (eg., that guy who lives in his mom's garage and has a web site defending geocentric astronomy).

Ergo, this science is not completely settled.

This would mean that no science is settled until the old men die--it does not allow for science to be settled so long as there is an "inside the system" person who voices disagreement, regardless of his reasons or the merits of his argument.

There is no means in academia for cranks to be forced out. And people who are part-time cranks but still do some good science, too (Balling, Lindzen) would be problematic cases if there were such means.

Don't worry, most science is settled, but this definition. The science that we rely on when we turn on a light, use an ipod, drop a hydrogen bomb, etc. Settled science won't disappear if you stop calling people like Lindzen a "crank." What seems likely to me is that catastrophic AGW has not attained the status of the science that enables the computer I am using to work.

Observational science can never reach that status--that's too high a bar.

But think: For AGW ("catastrophic" is a blogosphere canard) to be "wrong" in the colloquial sense, fairly elementary theory of the radiative properties of gases would have to be wrong, too.

Lindzen doesn't go that far, but many of these would-be "skeptics" do. "I don't believe in basic spectroscopy or radiation theory, and I vote."

One of Susan Haack's justified complaints against Rorty's account of truth is that, in a world where everyone believed it and behaved accordingly, inquiry would be replaced by lobbying. As a field of inquiry that has become (for non-Rortian reasons) infected with the spirit of lobbying, climate-change science serves as a cautionary tale.

I think that the problem here is that nothing is ever settled in the ultimate sense. You never reach a point where it is literally impossible not to believe something. But that doesn't mean some things aren't more certain than others. The earth is more like a sphere than like a flat plane. It is only very nearly an oblate spheroid. And we are more certain of these facts than we are of global warming. But by the same token we are more certain about global warming that global warming is happening than we are in its precise degree and effects. It would be nice if instead of pretending that there is a technical disagreement about the science we would instead have a moral argument about how much our precious little planet really is worth to us and about whether according to that valuation this or that legislation will make us better off. I am pretty sure cutting black carbon emissions and methane emissions would make sense even to libertarians, but only if they pull their heads out of the ground. I would very much prefer modest steady changes in policy, but our political institutions aren't set up for that. Bush could have done this low hanging fruit back in 2003 but he was an ass.

If there's significant uncertainty about the precise degree and effects of global warming then we would seem to have a real disagreement about the science, not a pretend one.

The one good thing I can say about the idea of replacing fact-finding with consensus-building is that it's not as bad as replacing fact-finding with moral bullying.

It would be nice if instead of pretending that there is a technical disagreement about the science we would instead have a moral argument about how much our precious little planet really is worth to us and about whether according to that valuation this or that legislation will make us better off.

You can't base morality on lies. We had food riots because well meaning 'moral' people decided that it was a good idea to divert food to fuel even though the process did not save energy, reduce carbon emissions or save money for consumers. What we wound up with was an energy neutral activity that forced consumers to subsidize farmers while poor people around the world had to do with less food.

I am pretty sure cutting black carbon emissions and methane emissions would make sense even to libertarians, but only if they pull their heads out of the ground.

What does this have to do with regulating CO2 or global warming? I don't see the AGW movement argue that the government of India should ask that power plants use scrubbers to reduce its soot emissions. Instead it argues that the government should not allow power generators to build any new coal plants and by doing so condemn many to poverty.

Bush could have done this low hanging fruit back in 2003 but he was an ass.

He was an ass but he could not do anything because the momentum was on the side of warmers. You also forget the fact that it was Clinton, not Bush who killed Kyoto. (As he should have.)

"Instead it argues that the government should not allow power generators to build any new coal plants and by doing so condemn many to poverty."

Geez, this "Vangel" is the real champion of the straw-man argument...

The two mainstream mitigation proposals being considered are carbon taxes and carbon trading--within states/countries. Internationally, just agreements for reductions--no dictating of how the reductions must be effected. Currently it looks like promises for reductions in India are future directed, with this "carbon intensity" talk.

You can make up fictional opponents all you want, but don't expect to be taken seriously until you address the real ones.

India is not stupid enough to stop building power plants and won't agree to it. Like China, it will say that it is doing good by reducing its carbon intensity, which is what happens naturally in developing countries. The cuts are supposed to come from the developed countries, which will see their costs of production increase and lose jobs to China/India/Brazil/etc. The carbon trading won't cut emissions (it didn't for Europe) and the only people that will benefit are the traders who deal in carbon indulgences.

I've always liked Austin's:

"'What is truth ?' said jesting Pilate, and would not stay for an answer. Pilate was in advance of his time."

Will,

Characteristically interesting post. I think my issue hinges on your claim that "in that case, “the science is settled” means something rather different than what it means to most competent speakers of the English language."

I understand what you mean but I do think that in this context the phrase "the science is settled" can be taken to mean x% of experts agree on the following topics.

Thankfully, one's views on AGW aren't really relevant to this issue. It's a matter of whether you insist on something of a literal reading of the phrase "the science is settled" which allows itself to be thwarted by the paradox you describe above, or whether you endow the phrase with a definition befitting, in my opinion, its context in this case which would be one that allows for a percentage of agreement by legitimate experts that is less than 100%.

Why concern ourselves with experts and not the state of the science itself?

It's unrealistic to think we ever make a decision entirely on "the state of the science." Trust in "experts" or whatever you'd like to call them is always important.

And since the time and knowledge required to understand certain aspects of climate science are prohibitive for many people, taking the temperature of the expert community, so to speak, is important.

Side note: it's really annoying to see so many of these comments are about climate science. This isn't a post about climate science. If you really think a comments forum is a good place to discuss this stuff at least go somewhere where that's the topic at hand. This is a post about philosophy of science.

"Taking the temperature" is important here--but it should be done to gauge the state of the literature and not the opinion of "experts", whatever those are. Hence review papers. Hence the IPCC process.

Will's dilemma has a very easy solution. To both mainstream experts and contrarians we ask "what's your argument"? Even referencing the literature is an answer--it's probably the most common. If the argument is uninformed by the literature, out of date, or specious, out they go!

Well, sometimes we ask contrarians "What's your argument?" Sometimes it's more convenient to dredge up careless opinions they've offered on unrelated subjects that can be used to dismiss them as loonies.

Well, sometimes we ask contrarians "What's your argument?" Sometimes it's more convenient to dredge up careless opinions they've offered on unrelated subjects that can be used to dismiss them as loonies.

The sceptics have a clear answer. Science shows that the climate is always changing and has been much warmer and much cooler not all that long ago. If the AGW proponents claim that it is human emissions that are causing the warming noted after the PDO flipped into its positive mode in the 1970s then they need empirical evidence to support that claim. The fact that they don't have anything except for narratives and faulty models tells us all that we need to know. And let me point out that the CRU e-mails show a great deal of uncertainty on the part of the leading voices supporting the AGW thesis. The sceptics see no justification for spending trillions when that uncertainty remains as high as it is. They want to open up the process so that everyone has access to the data and the reconstruction algorithms as well as an open debate that looks at all of the evidence that the IPCC has been ignoring.

Where both you and Hseih seem to go wrong is to consider people of a special class, "scientists", as opposed to arguments.

When one argues that "the science is settled" it is an argument that, considering the totality of the evidence, we can conclude X unambiguously and there is no sound evidence-based scientific argument contra this position That takes a scientist with a bad argument out of the picture--the irrational holdouts do not have to die for the science to be settled.

The "categorical" questions that capture the public's attention-- have emissions warmed the Earth and acidified the ocean, and will they continue to do so--are settled in this respect. It would take a lot of new evidence to unsettle them. The quantitative climate sensitivity is not settled like this.

Lindzen perhaps represents the outer bounds of respectability on that question, although the degree to which his "Iris hypothesis" is based on anything more than fancy is questionable. I'd say he's arguing from equivocation when he declares "the science" unsettled--yes, whether 2X CO2 will produce 2 degrees or 6 degrees (Kelvin) of warming (etc.) is still an open area of research, but that's not what the public "hears"--they read "the science is not settled" as having to do with the categorical questions.

@ Mr. Kalafut, who says: "When one argues that "the science is settled" it is an argument that, considering the totality of the evidence, we can conclude X unambiguously and there is no sound evidence-based scientific argument contra this position"

By this standard, there is very little settled in science. Rarely is evidence entirely unambiguous, and most important 'scientific truths' are founded not only on evidence, but also on application of Occam's Razor. In consequence, major 'scientific truths' sometimes turn out not to be true -- or, more often, as the history of physics shows, incomplete.

But frankly, the anti-AGW glee at the recent material released, and the general howls of "unproven", all display a degree of epistemological demands combined with argumentative glee that provoke skepticism. Clearly, the whole issue has become ideologized, which leads the convinced (on all sides) to perform the kind of selective looking and slanted interpreting that the scientific method was designed, in the first place, to avoid.

And while there's no doubt that zeal has been rising on the pro-AGW side, the cacophony of hyperskepticism on the other side -- hyperskepticism that some very powerful vested interests have every reason to encourage both subtly and openly -- has been much louder at the outset, and is notable for its constant howls of 'gotcha'. Again, the science is unsettled because all science, especially about complex dynamic systems, tends to remain unsettled. But we live in the world that models talk about, and despite a strong solar minimum for the last decade, it's getting warmer in many places. No, that doesn't prove anything...scarcely ANY evidence 'proves' something -- but it doesn't undermine the hypothesis, either.

I think your invocation of Occam's Razor is wrapped up largely in my writing "evidence-based".

Ambiguity is also constrained by what we already know. Problems are not treated on their own; we insist for example that work on global warming be consistent with what we now about the spectral properties of certain gases in the atmosphere, that measurements of solar output inform the work, etc.

"By this standard, there is very little settled in science. Rarely is evidence entirely unambiguous, and most important 'scientific truths' are founded not only on evidence, but also on application of Occam's Razor. In consequence, major 'scientific truths' sometimes turn out not to be true -- or, more often, as the history of physics shows, incomplete."

The problem in the case of climate science is that the evidence does not support the conclusions by enough to make the type of statements that the IPCC is trying to make. While everyone can agree that we are warmer now than we were during the Little Ice Age it is fairly clear that we are cooler than we were during the Medieval Climate Optimum or Holocene Optimum.

Can we really agree that warming is better than cooling given the evidence of history? How about CO2 causing runaway heating when the geological evidence shows cooling even when CO2 was 15 times the current levels? Is CO2 really bad for life on this planet or human health? While one can worry, as CNN's Dr. Gupta does, about allergies due to more plant life and longer growing seasons it is hardly responsible to dismiss the benefits of more plant life and longer growing seasons. How can we worry about melting sea ice when the satellites showed that at the beginning of this year total global sea ice cover stood above the satellite era mean? How can we worry about polar bear populations when the data shows that there are more polar bears now than there have been for at least 60 years? Hurricanes? Well, the data shows a multi decade low for accumulated cyclone energy. How about natural factors like the sun? Can we really dismiss the evidence just because it is inconvenient for the IPCC? And do we ignore the AMO/PDO just because they spoil the IPCC's conclusions?

The bottom line is that we can't ignore the actual evidence and the complexity just because we want to pretend that we know something that we do not. We are better off admitting, as the authors of leaked e-mails do, that there is still a great deal that is not understood and that without fudging the data there isn't the great warming since the 1940s that the IPCC reconstructions are showing.

The categorical questions are perhaps a bad example, since they are also "settled" in Will's sense-- neither Lindzen nor any other scientific skeptic known to me would dispute them. One of the pathologies of the public debate is the way it focuses on the settled categorical questions at the expense of the scientifically contested, and far more important, questions of degree.

That said, when I hear people saying "the science is settled" it's usually intended to be an argument from (sufficient) authority, intended to support the Big AGW conclusion-- not merely a restatement of it.

No matter the motivation the statement that the science is settled is still wrong. Tens of thousands of scientists have signed petitions questioning the AGW theory and several hundred peer reviewed papers make a clear case that the conclusions are wrong. Few of the scientific organizations have polled their members properly so we do not know how large a percentage of the membership buys into the IPCC's conclusions.

But are these "scientists" also "scientific skeptics" in the sense used by Mr Zrimsek above?

As for peer-reviewed papers, see
http://greenfyre.wordpress.com/2009/11/15/450-m...
(again to not duplicate effort)

The "categorical" questions that capture the public's attention-- have emissions warmed the Earth and acidified the ocean, and will they continue to do so--are settled in this respect. It would take a lot of new evidence to unsettle them. The quantitative climate sensitivity is not settled like this.

No scientist confuses correlation with causation. That said, the correlation for CO2 as a driver of temperature is not very good because over the past century we saw about 50 years a century of data during which CO2 emissions were rising but temperatures failed to go up.

You are claiming that there is evidence that CO2 is a driver of temperature but cannot point to that evidence. Keep in mind that the sceptics point to the warmers' early smoking gun, the ice core studies, as evidence to the contrary. They point out that the ice core data shows that the temperature trend change came first and that CO2 followed after a lag of 800 to 1000 years. That makes CO2 concentration the effect, not the cause.

Lindzen perhaps represents the outer bounds of respectability on that question, although the degree to which his "Iris hypothesis" is based on anything more than fancy is questionable. I'd say he's arguing from equivocation when he declares "the science" unsettled--yes, whether 2X CO2 will produce 2 degrees or 6 degrees (Kelvin) of warming (etc.) is still an open area of research, but that's not what the public "hears"--they read "the science is not settled" as having to do with the categorical questions.

Lindzen was asked to be a lead author by the IPCC. He is among the best that science has to offer and has shown that the feedback assumptions made by the IPCC modellers is invalid. The IPCC knows this because it spreads the feedback discussion among several places rather than provide a central area of focus when the theory and data is discussed. And I suggest that you are missing the obvious about the effect of doubling of CO2 concentration. We already have data going back 100 years that tells us what happened to temperatures as the concentration of CO2 increased by about 40% of a doubling. Knowing that the effect of adding CO2 is logarithmic we know that getting to the full doubling will take us about as far as we have already gone. That would mean another 0.6C in warming at best, hardly anything that would justify spending trillions of dollars so that GE can get more subsidies and Goldman can rake in more profits trading carbon credits.

Regarding CO2 lagging: Are you here to repeat long-debunked talking points, to annoy, and to waste time?

Yes, in long-ago warming events CO2 was a feedback and not a forcing. Today it is different. What's so difficult about that? Are we so primitive that we can speak only of naive correlations?--and so stupid as to think that all climate change happens the same way?

Again, read the Working Group 1 section of the IPCC report, cover-to-cover, and turn to the references where you want to learn more. Attribution studies will do you a lot of good.


Lindzen is an illustration of what the problem is with "experts". Yes, he has produced and continues to produce good science. That doesn't mean that everything that comes from him should be taken seriously. Have a look at his Heartland Institute slides, for example. Not only is there political ranting that seriously calls his bona fides into question, there's also a graph of estimated linear feedback factors that could not possibly have been produced using the methodology outlined in the talk.

Lindzen hasn't proved anyone wrong on feedbacks in the literature, either. The "Iris hypothesis" remains largely unsupported conjecture.

Lindzen hasn't proved anyone wrong on feedbacks in the literature, either. The "Iris hypothesis" remains largely unsupported conjecture.

Actually, there is plenty of support for Lindzen's findings.

Cess, R.D. and P.M. Udelhofen, 2003: Climate change during 1985–1999: Cloud interactions determined from satellite measurements. Geophys. Res. Ltrs., 30, No. 1, 1019, doi:10.1029/2002GL016128.

Chen, J., B.E. Carlson, and A.D. Del Genio, 2002: Evidence for strengthening of the tropical general circulation in the 1990s. Science, 295, 838-841.

Clement, A.C. and B. Soden (2005) The sensitivity of the tropical-mean radiation budget. J. Clim., 18, 3189-3203.

Hatzidimitriou, D., I. Vardavas, K. G. Pavlakis, N. Hatzianastassiou, C. Matsoukas, and E. Drakakis (2004) On the decadal increase in the tropical mean outgoing longwave radiation for the period 1984–2000. Atmos. Chem. Phys., 4, 1419–1425.

gee, he can't read well enough to find evidence of the increase, nor to find rebuttals to the "whack a mole" lagging-CO2 bit, but he sure can cut-and-paste.

Have a look at
Wong et al (2006), "Reexamination of the Observed Decadal Variability of the Earth Radiation Budget Using Altitude-Corrected ERBE/ERBS Nonscanner WFOV Data", Journal of Climate 19:4028-4039

The ERBE results pretty much knock the stabilizing iris conjecture out of the park.

You are providing a 2006 paper to refute one that was written in 2009? Try again.

Lindzen has already addressed the points. While he agreed that some of the reduction of the difference in the OLR could be attributed to orbital decay, " the reduction in Wong, Wielicki et al (2006) of the difference in the spikes of OLR between observations and models cannot be attributed to orbital decay, and seem to me to be questionable. Nevertheless, the differences that remain still imply negative feedbacks." The bottom line is that the IPCC still can't show positive feedback that it needs to support its scary predictions. Even if feedback is zero you still have only a further 0.6C increase for a CO2 doubling from the pre-industrial levels.

I also note something that Lindzen pointed out. Lindzen stated that every time reality intervenes and the data shows that the models are wrong the gatekeepers adjust the data to show more warming. But the only time the adjustments go the other way is when some outsider finds an obvious error in the data and methodology used to create the temperature reconstructions. The leaked e-mails prove that Lindzen was right about the data manipulation and also show how it worked.

You reference no 2009 paper and the original Iris paper is from nearly a decade ago. As I understand it Lindzen has been slowly weakening his iris conjecture over time...you provide me the reference and I will provide remarks. Are you talking about Lindzen and Choi? That's been "PWNed", as they say: see http://agwobserver.wordpress.com/2009/12/05/com... for starters--that way I don't have to duplicate effort. It's one of those junk papers that comes to conclusions in plain English that aren't there in the technical section--simply should never have passed peer review without more revisions.

The leaked e-mails show no such thing about data manipulation--and there's nothing in them that has come to light that could plausibly lead to retraction of even one paper. Every stupid argument about data manipulation--Eric S. Raymond's, Eschenbach's--has been knocked out of the park. Zero, nothing, nil to support this strange belief that the data sets are being revised in an ad hoc manner, not in the papers released to accompany the data sets and not in the stolen e-mails.

Lindzen's conspiracy theory remains even less well-supported than his conjectures about strong negative feedbacks.

Regarding CO2 lagging: Are you here to repeat long-debunked talking points, to annoy, and to waste time?

Nothing has been debunked. The ice core data shows that the temperature trend would come first and CO2 levels would follow 800 to 1000 years later. Look it up.

Yes, in long-ago warming events CO2 was a feedback and not a forcing. Today it is different. ....

Today is different? Sorry but you are not very convincing. You can't even show empirical evidence that we have seen much warming after humans began emitting a significant amount of CO2. Most of the warming took place before 1940 and emissions exploded after 1945. Yet, most of the raw data shows little in the way of warming after 1935.

"You can't even show"

Quit the wankery and just read the IPCC report.

Plenty of evidence presented there and in references therein.

But would somebody given to make the specious argument "CO2 was a feedback _then_ so it cannot be a forcing _now_" really care about evidence?

I have read the IPCC report. It has no empirical evidence that CO2 is a material driver of climate change. That is why it relies on computer models and why it has such a weak consensus statement in which it is claimed that human actions are 'very likely, the cause of global warming, instead of producing actual evidence that CO2 emissions drive temperature change. As I said, there is no consensus. Here is a list of 450 peer reviewed sceptical papers that cast doubt on much of the IPCC's deceit.

And if you want to be seen as having a credible position quit providing us with narrative and general statements and give us references to actual empirical evidence that supports the AGW thesis.

Chris Hallquist (unregistered) wrote:

How's this for a more charitable interpretation of "the science is settled": "98% (or so, or more) of the people who have the right scientific training and a record of serious scholar ship agree." The point about people who disagree is not that they don't count because they disagree, but that they don't count either because they're not experts or they're too small of a minority of experts.

One mistake is the 98% number. It is made up by the warmers and not supported by any objective evidence. The second is that they would not count because their number is too small or they don't have the knowledge necessary.

This poll exposes both of your errors. When polled by the AMS, 50% of American Meteorologists said that they disagreed with the IPCC statement, "Most of the warming since 1950 is likely human induced." Only 25% agreed. You clearly do not have a small minority of people who do not agree. It is also hard to argue that these people do not have knowledge about the issue because they are much more likely to know the debate than most.

But even if you were right about the number you would be wrong to dismiss the people who disagree. After all, it was a very small minority that believed the plate tectonics theory and it was a small minority that believed that the consensus view on the causes of ulcers was wrong.

I take it that there are good pragmatic reasons to use the phrase this way--we want to be able to say "it's settled that the Earth revolves around the Sun," we want to be able to say that even though surveys show many laypeople don' t believe this, and we would want to be able to say this even if there were a single guy with a Ph.D. in physics going around saying otherwise.

But that is the point. We do not use consensus to show that the Earth revolves around the sun because we have evidence that does the job. That is the problem with the warmers; they have no evidence so they run from debate by talking about a false consensus.

In any case, though, the evolution and solar system examples are good reasons to think that mere presence of dissent is not good reason to withhold the "settled science" label.

No the good reason is the lack of any evidence and evidence of fudging data and lying on the part of the AGW proponents and the IPCC.

The AMS poll you linked to surveyed weathercasters - the people you see on TV who interpret what meteorologists tell them - to see how much they were informed of climate research. They are PR frontliners, not climate scientists; indeed the paper you linked to distinguishes between climatologists, meteorologists, and weathercasters.

I mean, read the first page of the PDF you linked:

When weathercasters were asked in this survey to identify the “greatest obstacle to reporting on climate change,” their top answer (41%) was “too much scientific uncertainty,” despite the growing consensus of climate scientists evinced by the Intergovernmental Panel on Climate Change (IPCC) and in direct conflict with the AMS Statement on Climate Change.

So, y'know, consensus.

The AMS poll you linked to surveyed weathercasters - the people you see on TV who interpret what meteorologists tell them - to see how much they were informed of climate research. They are PR frontliners, not climate scientists; indeed the paper you linked to distinguishes between climatologists, meteorologists, and weathercasters.

No, I cited people that were meteorologists who were also 'TV weathercasters.' I am sure that had 'TV weathercasters' who were not meteorologists been added to the survey, the results would be very different because their lack of knowledge would make them more likely to go along with the mainstream.

It is also clear from the part that you cited that the meteorologists do not agree with the leadership of the AMS position. As such, we have to take the claim that the AMS totally agrees with the IPCC as a false claim. It is clear that there is plenty of dissent on this matter in the membership just as there is among the membership of many of the organizations that are cited in support of the IPCC position. Unless there is an actual poll of real scientists we will not know how many actually support or oppose the IPCC position. As I wrote before the argument of overwhelming consensus is a lie.

If by "the warmers" you mean the mainstream, the people publishing in the literature, there's plenty of evidence, beginning with spectroscopic measurements of CO2.

If by "the warmers" you mean the mainstream, the people publishing in the literature, there's plenty of evidence, beginning with spectroscopic measurements of CO2.

No, I mean the people who are making up narratives and lie about consensus so that people will be fooled. But it looks like people are not fooled because polls show that they place global warming way down the bottom of problems they want dealt with first.

And if there is evidence that shows that CO2 is driving temperature why not stop making up narratives and point us to it? We have already spent around $50 billion in research but have yet to show any empirical evidence that provides support for your position that human emissions are driving temperatures.

This is a very curious tactic, to pretend that scientists are not pointing you to the evidence. In no other field has so much effort been made to review and summarize the literature for the casual reader.

Look to the Working Group 1 section of the IPCC 4AR for references to attribution studies.

Of course, given what you write above, perhaps no attribution study will ever satisfy because no such study is purely empirical in the naive sense.

No true Scotsman doubts AGW.

Yes, and no true consensus ever has any dissenters.

Good for the goose is good for the gander, no?

The basic problem with everything I've read of you on science realism-- or, if you'll permit me, naive realism-- is that if you trace the logical string far enough, your argument is an inductive, consequentialist defense. Which is a weird way to defend a notion of capital-T Truth.

One thing I tell me scientist friends often is that what we might call a pragmatist vision of science does not in fact entail the insult people assume at all. Quite to the contrary, a use vision of truth is actually more respectful of science, because science is fantastically useful, and because such a vision holds science to an ultimately impossible standard.

Actually, I find the science realist position you espouse to have a facet that I think runs through some of your political writing as well, and to my lights the same problem, the problem of endless time horizons. If you say that science is currently imperfect but will someday, someday, arrive at the conclusions (the ultimate truths), you are effectively curtailing debate by prognostication. And there's no time when you have to put up, so to speak, because the horizons can simply be cast back farther into the future.

At some point, I think that people should consider that the evolutionary model which they believe in do to the perspective of believing it is objectively, timelessly and non-contingently true, and that I support because in the context of my own life I think it is useful, practical and for the benefit of mankind-- that this evolutionary framework for the origins of human life is unfriendly to the conception of science as real independently of context, or of a "perfect" science. If we agree that it appears to us that we do not encounter the world directly but through a medium we call consciousness, and if we further find it useful to think that the physiological structures which produce this consciousness are the products of evolution, and we further hold with the evolutionary biologists that evolution does not produce perfectly fit systems but rather only eliminates those systems so unfit that they prevent survival, then the odds of a human consciousness that is capable of perfectly and non-contingently interpreting the universe around it appear quite low.

Some say that we are in a universe that has objective truth, and that we are merely incapable of accessing it perfectly within our consciousness system. But the question of where that extra-human truth resides is the stuff of theology, and can seem to have no value for the consideration of how to proceed through human life.

I was emailing back and forth the other day about the generally low quality of comments on various sites and blogs and I have to say I haven't enjoyed a comment this much in a while.

Not really addressing the major thrust of the post but still relevant and definitely thoughtful.

I think that too many people are over-thinking what is a simple issue. The science is not settled and as long as it isn't we can't avoid debate by hiding behind a false claim of consensus.

Science is never "settled" (whatever that means) but at some point we do have to act. In my view we have passed all reasonable thresholds of actions and the time has come to transition to a clean energy economy. It might actually save you money too!

Computer models upon which these predictions are based are untested and unverified. The temperature models are already diverging. They are not holding good for even a couple of years, forget the decades they claim to predict.

One cannot throw billions of dollars based on the predictions of untested computer models. This was already tried, for Credit Default Swaps and derivatives, and it nearly resulted in a meltdown, of the global economy.

You're worried about acting in the face of uncertainty with "untested" models, but you have no problem running a decades-long unsupervised experiment in CO2 buildup using our only atmosphere as a guinea-pig?

Talk about shifting the burden of proof much?

It is clear that the models have failed to make accurate predictions and are quite useless at this time. Using them to justify any policy decisions would be foolish given the risk to the economic well being of people, particularly in the developing world.

Well, I am not an expert, but that statement is not "clear" to me at all.

http://www.realclimate.org/index.php/archives/2...

Anyway, my point was that uncertainty in the science can be seen as a point in favor of action.

But it is clear. The IPCC already admits that its models cannot properly account for factors such as changes in cloud cover, which means that the models are incapable of making predictions.

http://www.ipcc.ch/publications_and_data/ar4/wg...

The IPCC has also switched gears and talks about models producing 'scenarios' rather than 'predictions.' On the link below you can read that, Although there is increasing confidence among atmospheric scientists that increased atmospheric greenhouse gas concentrations will increase global temperatures, there is much less confidence in estimates of how the climate will change at a regional scale. However, it is precisely at this regional or local level (e.g. at the scale of a farm, a river catchment or even an individual organism) that climate change will be felt. Since no method yet exists of providing confident predictions of climate change at these scales, an alternative approach is to specify a number of plausible future climates. These are termed "climate scenarios".

http://www.ipcc-data.org/ddc_climscen.html

The RealClimate site does its usual bit of misdirections by showing the model performance after it has been tweaked on a regular basis. They do not show how the models did compared with the previous predictions and without the adjustments. A better picture can be obtained by looking at the IPCC's own figure

http://www.barrettbellamyclimate.com/userimages...

There are also regional model predictions as well as model predictions about precipitation, CO2 accumulation rates, storm activity, or ocean temperatures. These are not doing very well either.

http://c3headlines.typepad.com/.a/6a010536b5803...

http://icecap.us/images/uploads/argodata.jpg

Here is what the predicted mid-tropospheric warming is supposed to look like.

http://joannenova.com.au/globalwarming/hot-spot...

Here is what the real world observations are showing.

http://www.aps.org/units/fps/newsletters/200807...

The bottom line is that what you have are deterministic models trying to figure out what a non-linear chaotic system will do over a long period of time. The creators of these models admit that they do not understand how to account for a number of important factors. Yet you expect and claim that the models make accurate predictions because the liars at RealClimate say so? I suggest that you look at the actual publications and figure it out for yourself. Things are not what you imagine them to be.