AEI's Steven Hayward and Kenneth Green defend their climate policy projects in the Weekly Standard. Here's a taste:
The irony of this story line is that AEI and similar right-leaning groups are more often attacked for supposedly ignoring the scientific "consensus" and promoting only the views of a handful of "skeptics" from the disreputable fringe. Yet in this instance, when we sought the views of leading "mainstream" scientists, our project is said to be an attempt at bribery. In any event, it has never been true that we ignore mainstream science; and anyone who reads AEI publications closely can see that we are not "skeptics" about warming. It is possible to accept the general consensus about the existence of global warming while having valid questions about the extent of warming, the consequences of warming, and the appropriate responses. In particular, one can remain a policy skeptic, which is where we are today, along with nearly all economists.
Of interest to those who have been following this story, Hayward and Green provide some backstory on their letter to Professors Schroeder and North at Texas A&M, and how this became a major story.
North declined our invitation on account of an already full schedule. Schroeder shared our letter with one of his Texas A&M colleagues, atmospheric scientist Andrew Dessler. Dessler posted our complete letter on his blog in late July, along with some critical but largely fair-minded comments, including: "While one might be skeptical that the AEI will give the [IPCC Fourth Assessment Report] a fair hearing, the fact that they have solicited input from a credible and mainstream scientist like Jerry North suggests to me that I should not prejudge their effort."
Dessler's story was linked on another popular environmental blog (www.grist.org), after which someone in the environmental advocacy community (the Washington Post suggests it was Greenpeace and the Public Interest Research Group) picked up the story and tried to plant it, with a sinister spin, somewhere in the media. Several reporters looked into it--including one from a major broadcast network who spent half a day talking with us in November about the substance of our climate views--but reached the conclusion that there was no story here. . . .
They further seek to place the episode in the context of a broader cliamte "inquisition":
The rollout of the IPCC report and the Guardian story attacking us coincide with the climax of what can be aptly described as a climate inquisition intended to stifle debate about climate science and policy. Anyone who does not sign up 100 percent behind the catastrophic scenario is deemed a "climate change denier." Distinguished climatologist Ellen Goodman spelled out the implication in her widely syndicated newspaper column last week: "Let's just say that global warming deniers are now on a par with Holocaust deniers." One environmental writer suggested last fall that there should someday be Nuremberg Trials--or at the very least a South African-style Truth and Reconciliation Commission--for climate skeptics who have blocked the planet's salvation.
Former Vice President Al Gore has proposed that the media stop covering climate skeptics, and Britain's environment minister said that, just as the media should give no platform to terrorists, so they should exclude climate change skeptics from the airwaves and the news pages. Heidi Cullen, star of the Weather Channel, made headlines with a recent call for weather-broadcasters with impure climate opinions to be "decertified" by the American Meteorological Society. Just this week politicians in Oregon and Delaware stepped up calls for the dismissal of their state's official climatologists, George Taylor and David Legates, solely on the grounds of their public dissent from climate orthodoxy. And as we were completing this article, a letter arrived from senators Bernard Sanders, Pat Leahy, Dianne Feinstein, and John Kerry expressing "very serious concerns" about our alleged "attempt to undermine science." Show-trial hearing to follow? Stay tuned.
Desperation is the chief cause for this campaign of intimidation. The Kyoto accords are failing to curtail greenhouse gas emissions in a serious way, and although it is convenient to blame Bush, anyone who follows the Kyoto evasions of the Europeans knows better. The Chinese will soon eclipse the United States as world's largest greenhouse gas emitter, depriving the gas-rationers of one of their favorite sticks for beating up Americans. The economics of steep, near-term emissions cuts are forbidding--though that's one consensus the climate crusaders ignore. Robert Samuelson nailed it in his syndicated column last week: "Don't be fooled. The dirty secret about global warming is this: We have no solution."
Related Posts (on one page):
- "Scenes from the Climate Inquisition":
- The Senatorial Inquisition of AEI:
- On Ad Hominem Arguments:
- WaPo on AEI Funding Climate Critiques:
- Did AEI Seek to Buy Climate Scientists?
"The IPCC has actually lowered its estimate of the magnitude of human influence on warming"
No it hasn't
As the evidence for global warming mounts, the deniers (and the Adlers of the world "It's not that I don't believe in global warming, it's just that I think these serious scientists who have different opinions are being treated like pariahs by the global warming Nazis") are getting more shrill and are required to distort the evidence, or outright lie, even more.
No matter how much you bitch about it or claim otherwise, the climate change denial scientists get plenty of press, plenty of attention, and plenty of respect, especially considering how little science they have to back up their fringe theories.
What is Lord Monckton's link with the AEI? You obviously want to imply a link, but I can find none.
I am trying to read through your post. You disprove Monckton's statement (e.g., the IPCC halved their sea level estimate from 2001), but your proof actually seems to support the AEI statement (e.g., the IPCC reduced their sea level estimate from 2001).
I realize a non-expert reading the writings of a non-expert can always create problems. So please correct me if I misunderstood what you were writing.
I guess if the MSM looked into this and found nothing, there really is nothing...
If we do not currently have a correct theory of global warming how do we do something to solve the problem? How do we know that our solution will not exacerbate the problem? Without man’s influence, the earth has cycled through periods of cold and warm. We are currently somewhere in the middle of an interglacial period, which means that if we remove the so-called anthropogenic forcing function the earth will sometime in the future enter another ice age. But I guess that is okay, because that is due to natural causes and not mankind.
i could have sworn that my high school and college chemistry, biology and physical classes had textbooks. were they blank inside?
As to the Weekly Standard article, accusing your opponents, whether political or scientific, of desperation is pretty pathetic. Does AEI fail to realize that it sounds like the Discovery Institute commenting on the Kitzmiller case?
step 1: hypothesis/theory - for instance, that CFCs will cause the ozone to decay.
step 2: where possible, a small scale model - if I put ozone and CFCs in a box in my lab, will the CFCs degrade?
step 3: modeling. if, in the past, CFCs correlate with with ozone decay, can I predict what the size of the ozone hole will be in future years based on the factors including CFCs, solar wind, temperature, etc.
step 4: sit back and watch the experiment (ie, the real world) run. did my model predict what would happen?
step 5: assuming model did not perfectly work, revise step 1.
This is the same sort of observation -> hypothesis -> model -> observation that has been used ever since Kepler realised there was something wrong with the Earth-centered model of the universe... and probably before that.
Not so long ago, chemistry books had pictures of electrons spinning around atom nuclei like planets. Your point?
but it's also the case that some disciplines are more mature than others. Last I checked, no one has stuck an electrode into water and gotten two parts helium to one part water. on the other hand, i'd love to hear what dark energy and dark matter are.
"The derivative of e^x with respect to x, the U.N. and 85% of politically-significant mathematicians agree, is e^x."
or:
"Pi, scientific consensus agrees, is exactly 3.14159."
Of course, in such a regime there would be no place for Galileo or Mendeleev--but surely that's a small price to pay, to gain such (politically-useful!) agreement?
Or as Bill Maher said, why don't you sit this next one out, Nostradomus.
Never argue with a computer teacher. Hooray for consensus!
Riptide thanks for giving us the comic book version of science. You do not understand the difference between models and theories. Models are used when we do not have a complete theory. With modeling we set values for parameters in the equations because we don’t have a basic understanding of the science to know what the value should be. If the model gives results that seem to fit the measurements we then must come up with a scientific explanation of why for example a value of 1.5 in the exponent of the equation produces results that agree with the measurements. The model is just a useful tool for trying to understand the physical laws. It should never be confused with a theory.
Readers also might be interested in a description of the conference call between an Exxon representative and climate bloggers. This was set up by Exxon. Back Seat Driving has some comments on this.
Finally, I think that I have an answer to my previous question. Green clearly said on As It Happens that only a few climate scientists got the letter and more were sent to economists and policy people. It appears that there were two letters. The earlier one was centered on science and made an unconditional offer (at least to North and Schroeder). The second is conditional offering UP TO $10K This is a strong indication (sort of like when you find a trout in your milk, that the milk was watered) that even AEI believes the science is clear enough and that the debate has moved to the what to do stage.
North's reply to AEI may have said that he was too busy, but that is not what he told Schroeder and Schroeder repeated on As It Happens
Science does not work by consensus. If works by being able to correctly predict the results of experiments. If we get a theory that has been tested 100 times and has produced the correct results we can be fairly confident that the theory represents reality. Most scientists would agree that it was a good theory. But it is not the consensus of the scientists that makes it a valid theory but the fact that it gives results that are correct. Science only advances when we are able to replace established theory with better ones when the existing theories are no longer able to correctly predict the results of all experiments. If we practiced scientific consensus those experiments would never be carried out because scientific consensus tells us that the existing theory is correct and should not be challenged.
Which is, of course, a fantastically valid physical theory (yes, IAAP) that enabled the invention of many things you now take for granted - electricity, fertilizers, fuels, plastics, drugs etc. It also explains all manner of physical phenomena - the spectrum of hydrogen, why metals conduct and are shiny but plastics don't and are dull, why the sky is blue etc .
Furthermore, the quantum mechanical correction to the behavior of the atom actually give you back the same picture if you look to the expectation value (the "mean" position, in a sense) - mathematically | r^2 | =a_0^2 where a_0 is the classical radius. Of course QM is a lot richer in its description and makes finer-grained predictions that have been proven correct by experiment.
It's like flying over the Indy500 and observing that it looks like a line going around an oval. Just because there is more detail to be had (i.e. cars switching places), doesn't mean that the observation is wrong. It's right! Every theory has a scope - the Bohr model that you cited is right on the scale of atoms and materials but wrong when you look really closely at what the electrons are doing. When it was made, we couldn't see that closely at any rate.
I'm not a climate scientist so I can't speak to the IPCC's conclusions directly but I'm quite disinclined to believe the vast-conspiracy theory that the AEI is putting forward here.
The bit about model and theory is just an upgrade to evolution is only a theory. It can be said, for example, that evolution provides a model through which one can interpret the fossil record.
And I'm sure they still do. They did when I went to high school in the seventies, when such a depiction was known to be highly inaccurate and oversimplified. It wasn't until I was a freshman in college that I learned the orbits were really more like clouds. Then two years later in physical chemistry I learned that electrons will jump from shell to shell and never be in the space in between. How on earth can that be? Just because a oversimplified picture of the atom is used as a teaching tool does not mean it is necessarily wrong. The current understanding of the atom (or at least the orbits of electrons) predates World War II.
I'll say this for everyone else because I assume you know it. The values for parameters of equations in models are not just picked out of the air. In most cases the values are derived from data already in the literature and/or must be justified a priori. When we use them in physiology we also perform sensitivity analyses which tells us how varying a particular parameter value alters the output of the model. This is a hypothesis that can be tested-does a particular parameter matter to the outcome. And that is the nice thing about models, they focus your attention on characteristics that matter with respect to the outcome. You'll notice, as Tim Lambert comments above, that the IPCC needs to add or refine estimates of ice flows to get a more precise estimate of sea level changes.
The science will keep chugging along, whether we act on the predictions is an economic and political choice.
No. Science *does* work by consensus because we require that an experiment work 100 times when performed by 100 different researchers. We require that a scientist convince us that the experiment actually proves the thing he alleges that it proves (i.e. that the design of the experiment is concordant with the intended weight of the results) and that his explanation of that result follows. If nobody else can reproduce his results or if we disagree about what the experimental result means (design again) then more work obviously needs to be done.
This is semantics. If it's is concordant with reality then it is, in some epistemological sense, true. In this sense, Quantum Mechanics was a good theory (since it gave results that are correct) back in the days of Aristotle even though no one had written it down. What is meant by scientific consensus is that a theory has, by force of reason and result, convinced a large number of people well-versed in the field that it correctly gives results in agreement with reality.
There are two components, then, of the scientific *test* of a theory. The first is purely mechanical - does the math work and do the experiments work. The second is purely human - can you convince knowledgeable that the first test works. These days it is almost certain that if you've got the first part right, the second will follow (provided that there are people interested in the field at all - there are a lot of fringe areas of science that are perfectly valid but nobody cares).
Again, wrong. The scientific consensus almost invariably includes a call for more research on things that are not well understood. Virtually every scientific paper ends with a discussion on what more needs to be done (and there is always more to do!). No scientist has ever, EVER, implied that because we have consensus on what we know, we ought not to experiment on things we don't (or to get a better understanding of things we do know).
Scientists are KEENLY aware of the limitations of their theories. It's always way out in the very front of the paper where they spell out under what conditions their theory works (e.g. equilibrium lattice QCD) and where it doesn't seem to apply consistently (due to assumptions not being realized - e.g. far from equilibrium).
In a larger sense, scientists in a field often have a strong consensus on what needs to be worked on (e.g. in 1900 it was the ultraviolet catastrophe, in the 50's it was the spectrum of mesons, now it's quantum gravity) even when there is very weak consensus on what form that solution will take. The large shifts (in physics at least) were all preceded by intense discussion of important flaws and what can be done about them.
It continues to amaze me the hostility people have towards science after all its done for them (and their continued favorable look of other endeavors after all the harm it has caused them). That's a different rant i guess.
You need to actually read what the climate folks were saying twenty years ago, not some half-assed retelling on someone's web page.
They haven't just narrowed the error bars, they lowered the "most probable" scenarios, and have even mentioned that some of the models show a decrease(!) in sea level over the next hundred years. In the 1980s, the "most probable" sea level change was 0.75 meters, about twice the "most probable" we're being told about now.
There were some really huge (and dumb) assumptions about things like CO2 levels (some high estimates showed a tripling of CO2 over the next half-century - yes, upwards of 1100 ppm), with the muttered caveat that they didn't know how much CO2 got sucked out of the air by plants (yes, they did, they just chose to ignore it until the skeptics pointed out that plants actually did use CO2).
Temperature predictions were similarly extreme, with at least one showing the "middle" scenario as an increase of 0.3 degrees centigrade per DECADE, with the upper as 0.8 degrees C, and the "low" estimate being 0.06 degrees C. Guess which one is closest to the current "middle" estimate...
Then there's insolation, the great hole in the anthropogenic wall. A lot of climate scientists still seem to think it's a constant (no, it really isn't), or that it's a minor part of the equation (it really, really isn't).
No, actually, I am a physicist and everything I cited can be derived from the classical Bohr model and Maxwell's E&M.
My point is that the electron-orbiting theory is a perfectly good theory on the scale to which it applies. I can explain the blueness of the sky with Bohr + Maxwell just fine. It explains how we can separate crude oil in its constituents and what the chemical properties are.
It's a coarse-grained understanding of the atom - nothing more and nothing less. If we look closer we see more detail (just as in the Indy500 example).
No the reason he doesn’t get it “almost” right is because he is confusing model with theory. To give a simple example, Einstein did not come up with his equation E = mc**2 by modeling the relationship between mass and energy using E = mc**x and then trying different values of x until he found the value that gave the correct result. Rather Einstein had some deep insight into the problem that led him to come up with the correct equation. A model on the other hand deliberately simplifies the science in order to see if the equations that are used in the model can give results that agree with experimentation. By definition the model is incomplete. Unfortunately, the more terms that we add into the equations in the model to get results that are closer to reality, the less likely the model represents reality.
Well it neatly encapsulates the three step program:
1. There is no global warming
2. Global warming is not manmade
3. Global warming is so far advanced we can't do anything about it.
Note the use of 1 and 2 to make 3 plausible.
Once others accept this new paradigm, there is a limited sense of "consensus" as other scientists work to replicate the results. Sometimes the dominant theories may change with new evidence (e.g. evolution). At other times, the evidence is consistent so change to the paradigm may not be needed (e.g. gravity).
While some topics are more controversial and more political, such as evolution or global warming, scientists form interpretive communities about these topics and possess consensus, either for or against, on the topic within this community.
It seems entirely possible.
Oren, if the 101st experiment showed that the theory was incorrect/incomplete then we would not say that 99 percent of the scientists agreed with the theory now would we? So science does not work by consensus but rather by the accuracy of its predictions.
Scientists are KEENLY aware of the limitations of their theories. It's always way out in the very front of the paper where they spell out under what conditions their theory works (e.g. equilibrium lattice QCD) and where it doesn't seem to apply consistently (due to assumptions not being realized - e.g. far from equilibrium).
Since you state that scientists are aware of the limitations of their theories** then where is the disagreement with what I said? If the term scientific consensus was being used to indicate that the majority of climate scientists agreed with the global warming hypothesis then I have no problem with that. However, the term scientific consensus is being used to prevent the expression of contrary views by anyone including established scientists. In another context it would be humorous to learn that there are people so ignorant about science that they would use the expression global warming deniers. However, in this context I don’t see the humor. What we have are people who are trying to subvert the scientific process by prevent anyone from questioning the existing scientific orthodoxy. I would hope that would bother you.
**Of course some theories are more equal that other theories. We didn’t see those qualifications made with respect to relativity or QED.
Two things: the idea that science is defined by the "accuracy of its predictions" is sort of a junior high school science teacher's understanding of the process; i.e. keep track of all the steps in you lab book kids.
In any event people who actually do science for a living understand that even a 95% accuracy rate is statistically significant, let alone a 99% accuracy rate.
Your comment so profoundly misses the point that you (almost) leave me speechless. Or as Wolfgang Pauli once commented it is not even wrong.
And I really don't get the talk about models. No scientific problem that can be approached mathematically can be dealt with without the use of a model. Say you want to predict the orbit of some asteroid between the earth and Mars. No matter how many sophisticated theories you throw it, you're not going to get anywhere unless you assume the earth, the Moon, and the Sun are spheres, the gravitational effect of the distant stars is zero, and so forth. That's a model: it's not true, it's just close enough to the truth that the deviations between the model's predictions and reality should be very small.
Eli Rabett - exactly. What we have here, basically, are a bunch of elite pro-business/libertarian conservatives who are committed, on ideological grounds, to the belief that government intervention in the free market is always wrong. Global warming, if true, is an unusual case of empirical falsification of an ideological system. So, to avoid cognitive dissonance, they've danced seamlessly between "it doesn't exist," "it's not manmade," "there's nothing we can do about it," and "it's good." Anything to avoid the conclusion that government regulation of the marketplace might make things better.
He did? That's not what the WaPo article said.
I guess you can just make it up as you go along and hope nobody calls you on it.
To the contrary, it's very testable. We're testing it right now.
The "not well understood" part of the climate equation is what gives most global warming critics pause. Global warming "true believers" are willing to cause massive, predictable, and certain economic harm to economic growth (and by extension, education, medicine, and the general welfare) as a precaution against a potential harm that may or may not occur, and may or may not be affectable or controllable by humans. Would it be a good policy to plant trees, which remove CO2 from the air, to help reduce global temperature? [Unexpected answer: it depends on the latitude in which they are planted... high latitude trees actually increase surface temperature by replacing white [reflective] snow with dark [radiation absorbant] foliage]
My problem with the mathematical models is that the advancement of "science" here seems to be by tweaking and adding variables to better fit data - when all it takes to match any set of data points is enough variables.
Also, that when someone questions the models being used, they are now being considered on the level of a Holocast Denier. For me, it is more indicia of insecurity than of confidence, because if those calling doubters Global Warming Deniers were really that confident in their models and theories, they would welcome challenges.
But I will also admit that many of those who are the most adamant about this orthodoxy don't have the scientific background to really understand the problems with the models, and, indeed with scientific theory itself. I am not talking about the atmospheric scientists, but rather the journalists and politicians who tend to come from the humanities and social sciences, and are often there because of their lack of affinity for the harder sciences.
No, we're continuing to pump CO2 into the atmosphere until we see what happens.
But that isn't really testing the theory. Sure, maybe temperatures are maybe rising, in certain places and in certain situations. But do we have causation? Or is it merely correlation? And maybe the correlation is mere chance. After all, it is theoretically possible that some other phenomena are causing the general temperature to rise right now (for example, maybe solar activity), and the level of human produced CO2 is also rising right now. So, is the one causing the other? Or are they just happening to track somewhat in a similar direction?
One thing I have not understood about the debate- When the 'greenhouse' theory was first devised, it was used to explain the anomalous surface temperature readings for Venus (compared to, say, Mercury vis-a-vis its place relative to the Sun). Then the theory was applied to the Earth (and why we're at a livable temperature and the heat of the sun doesn't all escape into space).
This was completely uncontroversial- CO2 was a greenhouse gas, and it lead to warming. Nothing to see there.
However, when applied in the new context of apnthropogenic warming on Earth, suddenly everything gets squirrely. I can understand debating the range of warming (which is why the serious studies I have seen provide some attempts at quatifying the ranges), and the cost-effectiveness of solutions, but I fail to see why the following two statements are controversial:
1. People put out a lot of the greenhouse gases.
2. Greenhouse gases cause some level of warming.
The poor AEI. Facing criticism for its blatant solicitation of work designed to advance its agenda rather than advance the truth.
What an opressed organization. Though I suppose that is the consequences of forming an "intellectual" organization that is unapologetically not primarily interested in the truth when it conflict with their agenda.
Maybe they would be subject to facing an "inquisition" if they admitted that their solicitation letter was problematically worded, to say the least.
I found the following thing written by AEI interesting:
If it is true that AEI's critics have always been wrong, I don't see the irony here. What is different about this specific instance, that renders it ironic? That AEI went beyond not ignoring mainstream science, to actually seeking the views of mainstream scientists?
It should also be noted that AEI claim that it does not "ignore" science is an awfully low standard to hold oneself to. I could say that same thing about the relationship between Scientology and psychiatry. Scientology doesn't "ignore" psychiatry either.
Proposed new AEI slogan.
Well, what would you consider a test? We're continuing to pump CO2 into the atmosphere. Over what time period, and at what level of warming, will you agree that it's causal?
I doubt I qualify as an "elite . . . conservative," but this strikes me as a profoundly clueless argument. Just exactly how does one get from "Global warming is humanly caused" to "This disproves the belief that government intervention in the free market is always wrong"? First, I doubt you'll find many conservative/libertarians who take their opposition to government intervention to the extreme you suggest. Even ignoring your straw man, however, to show that such a belief was disproven by your premise, you'd have to show that government intervention sufficient to slow or stop global warming provided greater benefits and imposed lower costs than declining to intervene. And I don't think anyone has shown that. The lack of interest in that question strikes me as willful ignorance, not to mention enormously convenient for those who seize hold of global warming as an excuse for increased government regulation of the economy, protestations such as the following notwithstanding:
I mean, WTF: are we really to believe that it's only right-wingers who will grasp at any scientific (or pseudo-scientific) argument to justify their policy preferences? If so, you're welcome to your delusions, but please spare the rest of us the drama. See, e.g., genetically modified organisms.
is controversial.
But that, that in itself isn't controversial. The controversy is in degree.
Here, it's fairly easy to go through these things:
1. There has been significant average warming in the last 400 years. This isn't particularly controversial.
2. The amount of CO2 in the atmosphere has gone up over the last several hundred years: more controversial, but pretty strong.
3. CO2 is a greenhouse gas: not controversial.
4. An increased amount of CO2 would cause some warming: not very controversial.
5. The current temperature is clearly higher than in the last 1000 or more years: very controversial. Wegman's report calls the statistical basis into strong question.
6. There is a notable inflection in the rate of rise of temperature in the last century: very controversial indeed, as the statistical methods used in, eg, the Mann papers, have been shown to be very questionable. (That is, temperature has been rising faster than expected: not clear at all.)
7. The gains are anthropogenic, ie, caused by people: not at all clear, depends on 6.
8. Any anthropogenic gains are dominated by CO2: not at all clear, see Roger Pielke Sr's blog "Climate Science". There are a number of other forcing factors, from methane to city "heat islands", and several confounding factors, like the effects of aerosols.
Mostly true. I think a couple of ideas have gotten wedged in people's heads. First, many adults have now been subject to a so-called science education in grade school and high school. There we are taught about the "scientific method" and other such things. We also do so-called experiments; I rather distastefully remember one about starburst flavors. Ultimately though, these experiences are misleading. They bear some superficial similarity to reality but generally impart just the wrong ideas.
Second, ten or more years ago now, I started hearing members of the general public talking about 'peer review'. I believe this began in response to quite a bit of pseudo science: people publishing studies and reports which purported to be scientific but which were facially defective and publish through alternative means. It was here that we started getting a strong dose of 'but it hasn't been peer reviewed, its junk'. This quickly led to the idea that peer review imparts trustworthiness.
Sadly, just as believing in grade school science is misleading so goes the canard about peer review.
Let me explain: when something is 'peer reviewed' this means: It has been read by a few people and depending upon the stature of the journal in which it is published cleansed of its facial flaws to varying degrees. But this process does not involve reproducing the work in question, nor does it typically involve careful examination of the work. What it does do is screen-out work that is inconsistent with the greater corpus of the field. This not to say that inconsistencies do not reach publication; they do, but to do so also requires: at least one of: publishing in a lesser journal, substantial additional theoretical and experimental work, or an established reputation.
And there we see the heart of the matter. The trouble isn't so much that there isn't scientific consensus. There has been a fairly strong opinion on the subject of AGW for quite some time.
The trouble is that this opinion has shaped the boundaries of research done quite dramatically. People in the field are wont to point out at this juncture that many different models compete. They ask whether in the face of such competition how such consistency could result were it wrong.
The answer quite plainly is that many modeling differences are tolerated but a model that disputes the significance of AGW is not. Some people view this as a consequence of an idea similar to the anthropic principle: namely such a model is not tolerated because it is wrong.
But there is reason to believe the situation has gotten a bit further than that now. For example, we see in more recent publications desire and effort to purge from historical records certain time periods that contradict the hypothesis that global climate trends are principally the result of anthropogenic effects.
This is a dangerous place to be.
The science consists of several parts:
1) proxy studies: these are reconstruction efforts that attempt to deduce historic temperature and CO2 by means of various indicators. Many proxies, e.g., the bristlecone studies, provide rather poor data. Consequently, various statistical techniques are applied to the data. There is a strong effect of the 'scientific census' in this field. Correlated CO2/temperature is accepted as correct when the study begins and this assumption is used in part to direct and calibrate the results.
2) People attempt to develop models which are consistent with available data and then extrapolate from those models certain trends. There is nothing particularly new about modeling per se. Quite a lot of it is done in the world; and at least modern physics is about deducing mathematical models. However, in physics, a model is expected to be logically coherent. The goal is find a model that bests explains observation but has the fewest 'moving parts'. These models are known as 'white box' models in reference to our belief that we've quantified by the underlying nature.
Other fields (such as computational finance) develop black-box models. In these fields, the model is typically is without too much intuitive basis. It usually involves fitting many abstract parameters until a high predictive accuracy is obtained. Research in this field is held to a rather high standard: ultimate accuracy must be judged against a data-set other than the one used in developing the model. This is done to avoid the overfitting problem.
The models developed by climate scientists follow neither approach. Instead a typical approach is create a model by adding many different physical effects, e.g., cloud reflectivity, IR absorption of CO2, etc. These models are then tuned until they produce results which explain existing time-series and are used to used to produce predictions.
Close observation reveals that work in this field does not proceed along the lines of simplicity that normally follow in physics nor the statistical rigor used more generally in learning system theory. Its quite ad hoc. Work stops when enough effects have been included to explain that data or when the creators new one-off effect has been incorporated.
These models are not effective at ruling out other explanations; rather they are best at indicating that their fundamentals can be tuned to match prior datasets. This is the heart of the modeling controversy; this is why people remain unconvinced.
There are other kinds of models being worked on, ones that do not fixate on C02. These models appear to fit the existing data but relegate CO2 to being a minor influence. The trouble is that such work is now vigorously challenged and held to much stricter bar than the 'traditional' models. This is the consensus at work. But if the consensus is premature, this is a bad thing.
3) meta-studies of proxies and direct (modern) data. These attempt to take the work of #1 along with the time series available from modern instruments to discern whether the data admits of causal conclusions. This work is at least circular because of the 'consensus' that has taken hold among many of the people doing #1. These studies also compare physical modeling against the available time-series. This work is largely invalidated because the people doing #2 attempt to use #1 to calibrate their work.
Ergo, its quite circular and doesn't demonstrate much at all.
Ultimately science works by many people feeding off of each others work. This creates an intrinsic correlation whereby everyone contorts his efforts just a bit to be consistent with the prevailing views. When people initially begin pointing in the right direction, this is quite beneficial.
When not quite harmful; the most famous (accepted) case in which the consensus encouraged disaster is in the long resistance to the theory of tectonic plates in geology--which in part motivated a famous book, "The Structures of Scientific Revolutions"
In a mostly observational science such as Biology, you make falsifiable experiments by using your hypothesis to predict observations that have not yet been made. E.g., evolution predicts that humans and great apes have a common ancestor, so you predict that as more fossils are found, they'll find extinct species that have both humanlike and apelike characteristics. And they did. In cosmology, you predict what will be seen as they push the observational limits further out and closer to the Big Bang. That's also working mostly as expected - but the trouble is, there's not much difference in what competing models predict, and some of them (like string theory) seem to allow for so much tweaking that it's hard to imagine any results from astronomy or from accelerator experiments consistent with what has already been observed that would falsify string theory rather than just requiring a few more coiled-up dimensions.
For climatology, the problem is that new data appears at a slow rate. It takes decades to get enough new data to really test a model. Until then, all they are doing is re-running the models against the same data over and over again, which proves that they are getting better at curve fitting, but not whether they're getting any better at predictions.
Also there are known problems (such as the urban heat island effect) both with old datasets and the newest data. These problems are amplified by the fact that the global warming effect they are looking for is smaller than the noise (random variations) in the measured quantities, and also smaller than the corrections which have to be introduced (by what sounds to me like guesswork, mainly) for the urban heat island effect.
Finally, there's the whole problem that we know the temperature has cycled in the past (the Ice Ages) over a much wider range than anything we've experienced since the dawn of civilization, and we are a long way from a theory of why they stopped. We know that at least in certain parts of the world that kept historical records, there were large temperature changes between 1000 AD and the start of industrialization, and where the historical record gives the clearest temperature indications (southern Greenland) 1000 AD was obviously warmer. So, how do you prove the hypothesis that the warming of the last 150 years is due to human-caused emissions over the hypothesis that it's just part of the Little Ice Age cycle?
1. People put out a lot of the greenhouse gases.
2. Greenhouse gases cause some level of warming”
People and animals do emit co2, that’s not controversial. It’s the carbon cycle that counts. By burning fossil fuels we liberate carbon that was previously locked up, and change the carbon cycle so the equilibrium co2 concentration in the atmosphere goes up.
There is also no controversy that greenhouse gases can cause some level of warming. An increase in co2 concentration causes some warming, which increases the amount a water vapor in the atmosphere. It’s increased water vapor that causes significant warming. By itself co2 causes little warming because there is so little of it the atmosphere as compared to water vapor. But more water vapor means more cloud cover. The big question is will the increased cloud cover amplify or attenuate the warming? That’s where the controversy lies. If the clouds so created tend to be flat pancake-like clouds they will reflect more radiation abating the heating effects of increased water vapor. On the other hand, thick clouds will absorb more IR radiation from the surface and the heating effect will be enhanced. See J. Atmos. Sci. 29, 1413-1422 (1972). It’s not a small effect because an increase of 8% in the cloud cover would lower the mean surface temperature by 2 deg C. That’s about half the max predicted increase in for a co2 doubling.
These models are not effective at ruling out other explanations; rather they are best at indicating that their fundamentals can be tuned to match prior datasets. This is the heart of the modeling controversy; this is why people remain unconvinced.
As someone who's done plenty of work trying to deduce underlying models from complicated systems that have many strongly-interacting degrees of freedom, I can tell you that one of the biggest mistakes the novice makes is thinking that when he's found an explanation he's necessarily found the explanation.
This is rarely true. Usually it's possible to build several models that all fit the data. That's because it's a long, long chain of cause and effect between your model and the observations you use to test it, and typically you can't experimentally test what happens at each and every step in this chain to be sure your favorite model matches reality.
This means that even if a climate model matches observation perfectly, you have not proven the model is correct, unless and until you can also prove that no other reasonable model matches observation as well. That's a very tall order, when it comes to something as complicated as a planet's climate.
Arguably, this is one of the problems with the current politicization of global warming. When it gets to the point that there is no interest (or interest is discouraged), or money, to try on alternate theories, it becomes possible to mistakenly accept a plausible but ultimately incorrect model, with unfortunate consequences.
It has, after all, happened before. The plausibility of Aristotelian (dissipative) theories of mechanical motion -- the fact that these models seemed so reasonable in light of everyday experience -- made it very difficult to come up with alternative models like Newtonian (inertial) mechanics. Later the success of the wave theory of light and its intuitively appealing analogy with waves in materials led to a fruitless search for the luminiferous ether.
The case of the latter should serve as a particular warning: fortunately the existence of the ether, while very plausible -- no doubt the truth of its existence would be the "consensus" of the day -- was not taken entirely for granted. People did make measurements to be sure it was really there, and when those measurements suggested it was not, new ideas were born.
We should be very careful in science to avoid such deadly and foolish imports from politics as "consensus." Even assessing whether such things exist or not can weaken the urge to challenge orthodoxy which has always been one of the strongest guarantees of scientific accuracy -- one of the most important methods of preventing empirical science from degenerating into mere theology or law, where he with the strongest and most appealing argument wins.
I can only surmise that climate scientists seem unusually susceptible to this naivete because, being a very young science, they have not yet had much experience in finding that a theory which is wholly convincing, beautifully accounts for every known fact, and is accepted by everyone is, nevertheless, wrong. The physicists (relativity, quantum mechanics) and chemists (phlogiston, organic vs. inorganic) have suffered this painful reminder of the limits to human rationality many times over the past three centuries.
Excuse me? You are going to explain the Periodic Table with only the Bohr model? I'd like to see that. Tell me in particular how you get the Pauli Principle and the resulting shell structure of many-electron atoms. Or (since you're a physicist) how you can explain, using only the Bohr model, the curious lack of contribution of electronic degrees of freedom to the heat capacity of a metal at room temperature.
The problem that I (and others) have with the debate over global warming is the overall context in which it is placed. Imagine the following problem:
-Your daughter is scheduled to have a wedding on Sunday. On Thursday, the forecast calls for an 80% chance of rain. Do you pay for a tent for the reception, knowing there is a chance it might not be needed? Or do you attack the science of meterology, claim that rain can actually improve a reception, and decide that since the wedding is so close, it really doesn't matter what you do anyway.
Now, this thought problem oversimplifies a great deal, but it serves to bring out the fundamental issue- what importance do we, as a society, place upon possible outcomes in the future that could be incredibly dire? This is a question that has two parts- the scientific and the political. In the wedding hypo, the scientific is easy- what is the likelihood of rain? The political is dicier... how much does a tent cost? How important is your daughter's happiness to you? How important is your social standing ot your wedding guests?
To use another example... we *know* that a a large meteor will, at some time in the future, strike the earth doing a cataclysmic amount of damage. That is fairly well established scientifically (IMHO). What is not known is when. The political question becomes- what do we do about it? To this point, we have chosen, as a political matter, to not invest resources in defending ourselves against this threat because while the danger is great, the likelihood of it happening on our watch is miniscule.
On to global warming. I find the basic science uncontroversial (there is global warming caused by man). Again, these basic theories, when applied to why the Earth is the temperature it is relative to the Sun and why other planets are the temperatures they are, was uncontroversial. When it became politicized (do we, as a society, expend resources on this), it became very controversial. There are powerful interests that orefer to 'continue the debate'. I do find it interesting that the basic industry and political position has shifted over the past 20 years from:
1. No Global Warming
2. Global Warming? Maybe, but not caused by man.
3. Global warming may be caused by man, but it would be too expensive to deal with and we can just adapt. Hey- don't you like warm winters?
I think there are many issues on the scientific side that need to be fleshed out and worked on. But when people argue that there is no scientific consensus, or, more importantly, that the scientific consensus is unimportant, they miss an important point- how else are we to base the political decision?
Popper doesn't say biology isn't a science, nor does he say evolutionary biology is "non-science". I think it's a problem with you having never read Popper.
Really. I must have missed the revolution elevating the social sciences on a par with the physical sciences, when a philosophy of science that takes the hard sciences as the paradigm of scientific endeavour is regarded as inadequate when it does not explain the methodology of the social sciences.
But this is a mistaken impression. Since precisely this question is addressed in _The Poverty of Historicism_, and explains why the social sciences ought not to pretend that it could ever wear the mantle of the hard sciences for good reason. Again, do read what you criticize, rather than criticize a caricature of a position you think you;ve read.
As someone who has followed the creationism debate for a long time, I can say that this is exactly what the creationists say, all you need to do is replace "climate" with "evolution". This does not give me much confidence in the intellectual honesty of Heyward and Green. If you can't win on the merits of your case, pretend that you're being persecuted. The irony is obviously lost on them, but it's a signature tactic of Holocaust deniers as well.
Aside from the obvious falsehood of the claim (the IPCC itself does not "sign up 100 percent behind the catastrophic scenario", and no one's calling them denialists), it is apparently lost on Hayward and Green that what people object to is the flagrantly dishonest propaganda the deniailst movement keeps putting out. Their motives are suspect precisely because they keep using poorly reasoned and throughly refuted arguments. People like that don't deserved to be taken seriously. There is no "debate" to be stifled when one side doesn't debate the evidence.
So which is it? An assessment on the merits, or persecution as to the motives?
Okay Steve Reuland, I invoke Godwin’s law. You loose the debate.
And Godwin's law applies to comparisons to Hitler, not Holocaust deniers. As far as I'm concerned, comparisons to Holocaust deniers are apt as long as you're limiting the comparison to their intellectual habits.
Good lord, you can question someone's motives without persecuting them you know.
What a waste of time.
Simply learn not to conflate criticism of motivation with the criticism on the merits and we'll be fine.
There are more steps:
1. Is the earth warming?
2. Will this cause damage?
3. Is the warming anthroprogenic?
4. Can it be reversed technically?
5. Should it be reversed by reducing energy production or by 'national technical means'? (For example by nuking a mountain or a body of water converting it into atmosphereic dust or vapor and increasing the earth's reflectivity.)
6. Will the cure be worse thn the disease? (Is is better to be warm and rich than poor and cold?)
And as I think I stated quite clearly, the motives become suspect precisely because it's obvious that the merits are non-existent. You can only waste so much time with people who disingenuously claim to want "open debate" yet keep using the same wrong arguments over and over. At that point you say, "these people aren't interested in the truth, and here's why..."
Yes of course. You'd know this - "it's obvious!" - when the AEI studies haven't even been produced yet.
And please don't say their motivations/credibility is suspect hence the merits are non-existent - you already claimed you didn't conflate the two.
In a pretzel aren't we?