I think peoples' decision about whether to accept or resist the AGW proposition is being complicated by an implicit negotiation over political power that's inevitably attached to that decision.
Because the scientific projections are still vague, people feel as if their decision about whether to believe in AGW is underdetermined by the evidence, in such a way that political actors in the future will feel entitled to retrospectively interpret their decision for purposes of political precedent. ("Were they forced by the evidence, or did they feel weak enough that they made a concession they didn't have to make?") And the precedent won't be induced in terms of the mental states that a perfect decision theorist, thinking about the AGW mitigation decision problem, would have had. The precedent will be in terms of the mental states that a normal non-scientifically-trained (but politically active) human would have had. One of those mental states would be uncertainty about whether scientists (unconsciously intuited as potentially colluding with, and/or hoping to become, power-grubbing environmental regulators) are just making AGW up. In that context, agreeing that AGW is probably r...
I was wondering how long it would be until the AGW issue was directly broached on a top-level post. Here I will state my views on it.
First, I want to fend off the potential charge of motivated cognition. I have spent the better part of two years criticizing fellow "libertarians" for trivializing the issue, and especially for their rationalizations of "Screw the Bengalis" even when they condition on AGW being true. I don't have the links gathered in one place, but just look here and here, and linked discussions, for examples.
That said, here are the warning signs for me (this is just to summarize, will gather links later if necessary):
1) Failed predictions. Given the complexity of the topic, your models inevitably end up doing curve-fitting. (Contrary to a popular misconception, they do not go straight from "the equations they design planes from" to climate models.) That gives you significant leeway in fitting the data to your theory. To be scientific and therefore remove the ability of humans to bias the data, it is vital that model predictions be validated against real-world results. They've failed, badly: they predicted, by existing measures o...
http://www.overcomingbias.com/2009/11/its-news-on-academia-not-climate.html
Yup, this behavior has long been typical when academics form competing groups, whether the public hears about such groups or not. If you knew how academia worked, this news would not surprise you nor change your opinions on global warming.
People are crazy, the world is mad. Of course there's gross misbehavior by climate scientists, just like the rest of academia is malfunctioning. But the amount of scrutiny leveled on climate science is vastly greater than the amount of scrutiny leveled on, say, the dietary scientists who randomly made up the idea that saturated fat was bad for you; and the scrutiny really hasn't turned up anything that bad, just typical behavior by "working" scientists. So I doubt that this is one of the cases where the academic field is just grossly entirely wrong.
People are crazy, the world is mad.
It just occurred to me that this really needs to be the title of a short popular book on heuristics and biases.
Wha...? Is that an argument by surface analogy? Does every increase in every value owing to human intervention lead to a catastrophe? How about internet connectivity? Land committed to agriculture? Air respired by humans? Shoes built? Radio waves transmitted?
How do you even measure the reference classes appropriately?
What, specifically, is "damning" about those quotes?
Suppose creationists took over a formerly respected biology journal. Wouldn't you expect to find quotes like the above (with climate sceptics replaced by creationists) from the private correspondence of biologists?
I'm too lazy to write a top-level post about it, but the main problem with AGW as I see it is that most people have reference class of "statements said by people like IPCC and Al Gore, who think that AGW is real, and Kyoto Protocol and similar activities are a good idea".
One group of people look at pretty solid evidence that AGW is real, and from this and such reference class infers that Kyoto Protocol type actions must also be good.
Another group of people look at pretty solid evidence that Kyoto Protocol is a very bad idea, and from this and this reference class infers that AGW might not be real.
All media show these issues as highly entangled, even though they're not really (well, if AGW is false, then Kyoto Protocol is almost certainly bad, but all three other combinations are possible).
I have two reference classes - one for AGWers' statements about climate which I estimate to be almost all true, and another for AGWers' statements about proper policy which I estimate to be almost all false.
Part of the problem stems from different uses of the word "caution".
There are a range of possible outcomes for the earth's climate (and the resulting cost in lives and money) over the next century ranging from "everything will be fine" to "catastrophic"; there is also uncertainty over the costs and benefits of any given intervention. So what should we do?
Some say, "Caution! We don't know what's going to happen; let's not change things too fast. Keep our current policies and behaviors until we know more."
Others say, "Caution! We don't know what's going to happen, and we're already changing things (the atmosphere) very quickly indeed. We need to move quickly politically and economically in order to slow down that change."
For most people it seems that caution means: assume things will continue on more or less the same and be careful about changing your behavior, rather than seek to avoid a high risk of catastrophic loss.
Discussions about runaway AI often take a similar turn. People will come up with a list of reasons why they think it might not be a problem: maybe the humain brain already operates near the physical limit of computation...
While I loved this essay, I felt uncomfortable with the vagueness with which the group of "AGW Skeptics" was defined. If we define that group loosely to include every AGW skeptic, then there are obviously rationality impoverished reasons AGW skeptics have for their beliefs, but the same is true for AGW believers. Attacking strawmen gets us nowhere.
A worthy attack on AGW skeptics should be directed at the leading skeptics who have expertise in climatology. They are making very specific scientific claims, such as:
These claims - while I think we have good scientific evidence against them - are not obviously unreasonable. What is unreasonable is the insinuation in the essay that skeptics who are professional climatologists deny the claim "we know from physics that [CO2 is] a greenhouse gas". They don't - the real issue that the professionals debate is whether the addition of greenhouse gases will cause a positive or negative feedback (without a positive feedback, the warming from incr...
OT: Since the reference to Thorium reactors wasn't linked in the top level post, here are some links for those who are curious:
http://en.wikipedia.org/wiki/Thorium#Thorium_as_a_nuclear_fuel
http://www.youtube.com/watch?v=AZR0UKxNPh8
http://www.theoildrum.com/node/4971
The report of creationists deploying the tactic in question (finding a transitional fossil where one was not previously creates two gaps that now need to be filled by other fossils), is not a Poe.
As a very active member of the Richard Dawkins Foundation Forums (RDF), I can tell you that I have seen this ploy used on more occasions than I can count.
This is in addition to people who think that Evolution also means that there should exist the Crockoduck, the Cat-dog, and the Bird-fish (to name just a few), or that Evolution means that Polar Bears had the Colo...
I reviewed this topic last May:
The match between recent warming and CO2 rise details is surprisingly close, substantially raising confidence that CO2 is the main cause of recent warming.
When Kevin Dick offered to bet me, I offered even odds that the CO2-temp correlation over the last 60yr would continue over 20yr. Kevin pointed out that this is far less than standard projections, produced by assuming positive feedback models. So the key issue is how much confidence to place in such projected strong feedback. I didn't have enough confidence in it to...
This seems like a reasonable summary of the scientific consensus and I'm generally pretty willing to accept the factual elements of the scientific consensus. The judgment elements of the scientific consensus, such as "we should all be dedicated to cutting CO2 emissions" seem very much less reliable. It's noteworthy that people who accept the facts but not the judgments, like Dyson, are often called deniers.
And it is, in the second place, an attitude of trying to be defensible rather than accurate, the attitude of someone who wants to be allowed to retain the beliefs they have, and not the attitude of someone who is honestly curious and trying to figure out which possible world they live in, by whatever signs are available.
Defensibility and wanting-to-retain-beliefs both seem likely, but seem to me to be different things. Also, a third thing (or perhaps a variant of wanting-to-retain-beliefs) that I think is often involved is wanting-not-to-be-fooled: some...
A good way to turn this question around when discussing with an intelligent person is to ask this question: "What scientific evidence could be announced next year that would push you to change your position?"
This forces them to consider, at least, the source of their disagreement.
Not coincidentally, it's a question that we should frequently ask ourselves as well.
On the issue of "Have you ever seen an Ape evolving into a Human?" and the requested video tape (We get that too at RDF), I have found the following to be very helpful in showing just how stupid the claim is. Simply ask the person:
"How do you know that your father is really your father? Do you see him have sex with your mother to conceive you? How do you know that she did not have sex with someone else? Do you have a video tape to prove this?"
They of course, will have to admit that they take it as given based upon the testimony of their...
The basic point here is a good one, and it's obviously right as it applies to evolution and very likely to AGW as well, though I know very little about that and rely entirely on the fact of the scientific consensus in forming my opinion. But at the same time it is important to keep in mind that just because someone has worked hard and offered you the best evidence that they could be reasonably expected to muster under current circumstances, that doesn't necessarily mean that they have come anywhere near proving the case.
(And while we're on the subject, yes, the laws of probability theory are laws, rather than suggestions. It is like something the teacher tells you, okay? If you're going to ignore the Bayesian update you logically have to perform when you see a new piece of evidence, you might as well ignore outright mathematical proofs. I see no reason why it's any less epistemically sinful to ignore probabilities than to ignore certainties.)
Probabilities can't be ignored, of course, but nobody ever actually has the correct probabilities, except for in mathematics a...
Oh... I also thought that I would throw this into the mix.
When a creationist or evolution-denier says that "No one has ever seen an ape evolving into a man, or a dinosaur evolving into a bird." Often, what they mean is that an Ape literally turned into a man while it was alive. The more subtle creationist will just imply that a thing that was fully ape gave birth to a thing that was fully man, yet I have discovered that both types are to be considered about equally likely to be encountered.
Neither type of Creationist or evolution-denier seems to...
Eliezer:
Don't you realize that I have work to do and a personal life to engage in without you posting things that I must obviously drop everything and read and think about like the Bostrom paper. Have a heart, man. Have a heart.
the science of predicting what exactly is going to happen to the climate is pretty immaterial. humans are going to burn the vast majority of remaining oil reserves. base your plans on that rather than devoting resources to the losing battle of preventing other people from exploiting cheap energy.
"Human beings and chimpanzees have 95% shared genetic material. It's over." Where does this number come from? I've heard people saying the DNA was 98% the same since well before the human genome was sequenced, and the chimpanzee genome isn't completely sequenced yet. Where does this number come from?
I think the key is that most people don't care whether or not AGW is occurring unless they can expect it to affect them. Since changing policy will negatively affect them immediately via increased taxes, decreased manufacture, etc., it's easier to just say they don't believe in AGW period. If the key counter-AGW measure on the table were funding for carbon-capture research, I think many fewer people would claim that they didn't believe in AGW.
My take on global warming is that no policy that has significant impact on the problem will be implemented until ...
But we know from physics that it's a greenhouse gas. It's not a privileged hypothesis we're pulling out of nowhere. It's not like saying "You can't prove there's no invisible pink unicorn in my garage!" AGW is, ceteris paribus, what we should expect to happen if the other things we believe are true.
I realize that this is not a debate about global warming, but respectfully, you are wrong here. It's just that the privileged hypothesis is hidden from view by means of conjunction.
It may surprise you, but the actual global warming hypothesis a...
the whole point of decision theory is to choose under conditions of uncertainty
How about we say 'even under conditions of uncertainty'. Decision theory handles decisions under certainty too. See, for example, the majority of decision theory conversations around here. (It's just simpler discussing the certainty cases unless the uncertainty plays a specific part in the specific case.)
Re: "if there's something we can do about AGW, we need to do it now, not in a hundred years"
Sure we can do things about AGW - but why would we want to? Why exactly is a warmer planet bad? Since we are currently in an intergalcial in an ice age, a warmer planet would surely be a big win for the biosphere.
I've had a lot of internal battles over what to make of the AGW debate, and finally decided that if I'm willing to trust in science on evolution vs. intelligent design, I have to trust in science on AGW vs. nuh uh! as well.
After further reflection, I think my skepticism of AGW was motivated by a disdain for the people who use it as a vehicle for policy - "How convenient for you that there's a huge global problem that calls for exactly the same policies you were calling for earlier!"
I still think that policies designed to mitigate AGW (ethanol, ha...
The term "believe in" is used whenever someone else assigns a probability sufficiently higher than yours for you to take offense. For example, if someone assigns a negligible probability to hard takeoff and Robin Hanson assigns it a 10% probability, they will say that Robin Hanson believes in hard takeoff.
If you don't care about being honest, you should say it when it wins to do so.
If you do care about being honest, you should say it when doing so helps give the person you're communicating with an accurate estimate of your epistemic state.
A decent paleontologist doesn't need a creationist to ask this question. It's the second thing that you think of after 'wow, whose bone is that? Maybe someone's between A and B'. And if you can actually put forward a theory, however weird, of why there're two gaps, then you advance science. On the other hand, some questions (like the origin(s) of flowers) are so popular that more fundamental ones don't attract due attention( llike, what the heck did MIKC-type MADS genes regulate in plants in the 100 million years before flowers appeared?) And a smart creationist would ask you that. And it's not even evidence that you can't obtain.
"As I once said to someone who questioned whether humans were really related to apes: "That question might have made sense when Darwin first came up with the hypothesis, but this is the twenty-first century. We can read the genes. Human beings and chimpanzees have 95% shared genetic material. It's over." "
I don't believe any scientist worth their lab-coat would ever use the phrase "It's over".
One of the central tenets of science is constant questioning and healthy skepticism. Statements which imply that 'since it's good en...
So far as I can tell, the position of human-caused global warming (anthropogenic global warming aka AGW) has the ball.
I think you meant the opposite of what that entails. We usually say, "X has the ball" or "The ball is in X's court" when we mean, "It's X's responsibility to do something now". Thus, I initially read that statement to mean, "AGW proponents need to provide more evidence". Did you mean:
1 - AGW is the best hypothesis. 2 - People act as though the burden of proof is on AGW proponents.
This post disqualifies me from calling myself a rationalist in the LW sense. Allowing other people to force me to believe stuff is a river I'd rather not cross.
Followup to: Logical Rudeness
There's a story - in accordance with Poe's Law, I have no idea whether it's a joke or it actually happened - about a creationist who was trying to claim a "gap" in the fossil record, two species without an intermediate fossil having been discovered. When an intermediate species was discovered, the creationist responded, "Aha! Now there are two gaps."
Since I'm not a professional evolutionary biologist, I couldn't begin to rattle off all the ways that we know evolution is true; true facts tend to leave traces of themselves behind, and evolution is the hugest fact in all of biology. My specialty is the cognitive sciences, so I can tell you of my own knowledge that the human brain looks just like we'd expect it to look if it had evolved, and not at all like you'd think it would look if it'd been intelligently designed. And I'm not really going to say much more on that subject. As I once said to someone who questioned whether humans were really related to apes: "That question might have made sense when Darwin first came up with the hypothesis, but this is the twenty-first century. We can read the genes. Human beings and chimpanzees have 95% shared genetic material. It's over."
Well, it's over, unless you're crazy like a human (ironically, more evidence that the human brain was fashioned by a sloppy and alien god). If you're crazy like a human, you will engage in motivated cognition; and instead of focusing on the unthinkably huge heaps of evidence in favor of evolution, the innumerable signs by which the fact of evolution has left its heavy footprints on all of reality, the uncounted observations that discriminate between the world we'd expect to see if intelligent design ruled and the world we'd expect to see if evolution were true...
...instead you search your mind, and you pick out one form of proof that you think evolutionary biologists can't provide; and you demand, you insist upon that one form of proof; and when it is not provided, you take that as a refutation.
You say, "Have you ever seen an ape species evolving into a human species?" You insist on videotapes - on that particular proof.
And that particular proof is one we couldn't possibly be expected to have on hand; it's a form of evidence we couldn't possibly be expected to be able to provide, even given that evolution is true.
Yet it follows illogically that if a video tape would provide definite proof, then, likewise, the absence of a videotape must constitute definite disproof. Or perhaps just render all other arguments void and turn the issue into a mere matter of personal opinion, with no one's opinion being better than anyone else's.
So far as I can tell, the position of human-caused global warming (anthropogenic global warming aka AGW) has the ball. I get the impression there's a lot of evidence piled up, a lot of people trying and failing to poke holes, and so I have no reason to play contrarian here. It's now heavily politicized science, which means that I take the assertions with a grain of skepticism and worry - well, to be honest I don't spend a whole lot of time worrying about it, because (a) there are worse global catastrophic risks and (b) lots of other people are worrying about AGW already, so there are much better places to invest the next marginal minute of worry.
But if I pretend for a moment to live in the mainstream mental universe in which there is nothing scarier to worry about than global warming, and a 6 °C (11 °F) rise in global temperatures by 2100 seems like a top issue for the care and feeding of humanity's future...
Then I must shake a disapproving finger at anyone who claims the state of evidence on AGW is indefinite.
Sure, if we waited until 2100 to see how much global temperatures increased and how high the seas rose, we would have definite proof. We would have definite proof in 2100, however, and that sounds just a little bit way the hell too late. If there are cost-effective things we can do to mitigate global warming - and by this I don't mean ethanol-from-corn or cap-and-trade, more along the lines of standardizing on a liquid fluoride thorium reactor design and building 10,000 of them - if there's something we can do about AGW, we need to do it now, not in a hundred years.
When the hypothesis at hand makes time valuable - when the proposition at hand, conditional on its being true, means there are certain things we should be doing NOW - then you've got to do your best to figure things out with the evidence that we have. Sure, if we had annual data on global temperatures and CO2 going back to 100 million years ago, we would know more than we do right now. But we don't have that time-series data - not because global-warming advocates destroyed it, or because they were neglectful in gathering it, but because they couldn't possibly be expected to provide it in the first place. And so we've got to look among the observations we can perform, to find those that discriminate between "the way the world could be expected to look if AGW is true / a big problem", and "the way the world would be expected to look if AGW is false / a small problem". If, for example, we discover large deposits of frozen methane clathrates that are released with rising temperatures, this at least seems like "the sort of observation" we might be making if we live in the sort of world where AGW is a big problem. It's not a necessary connection, it's not sufficient on its own, it's something we could potentially also observe in a world where AGW is not a big problem - but unlike the perfect data we can never obtain, it's something we can actually find out, and in fact have found out.
Yes, we've never actually experimented to observe the results over 50 years of artificially adding a large amount of carbon dioxide to the atmosphere. But we know from physics that it's a greenhouse gas. It's not a privileged hypothesis we're pulling out of nowhere. It's not like saying "You can't prove there's no invisible pink unicorn in my garage!" AGW is, ceteris paribus, what we should expect to happen if the other things we believe are true. We don't have any experimental results on what will happen 50 years from now, and so you can't grant the proposition the special, super-strong status of something that has been scientifically confirmed by a replicable experiment. But as I point out in "Scientific Evidence, Legal Evidence, Rational Evidence", if science couldn't say anything about that which has not already been observed, we couldn't ever make scientific predictions by which the theories could be confirmed. Extrapolating from the science we do know, global warming should be occurring; you would need specific experimental evidence to contradict that.
We are, I think, dealing with that old problem of motivated cognition. As Gilovich says: "Conclusions a person does not want to believe are held to a higher standard than conclusions a person wants to believe. In the former case, the person asks if the evidence compels one to accept the conclusion, whereas in the latter case, the person asks instead if the evidence allows one to accept the conclusion." People map the domain of belief onto the social domain of authority, with a qualitative difference between absolute and nonabsolute demands: If a teacher tells you certain things, and you have to believe them, and you have to recite them back on the test. But when a student makes a suggestion in class, you don't have to go along with it - you're free to agree or disagree (it seems) and no one will punish you.
And so the implicit emotional theory is that if something is not proven - better yet, proven using a particular piece of evidence that isn't available and that you're pretty sure is never going to become available - then you are allowed to disbelieve; it's like something a student says, not like something a teacher says.
You demand particular proof P; and if proof P is not available, then you're allowed to disbelieve.
And this is flatly wrong as probability theory.
If the hypothesis at hand is H, and we have access to pieces of evidence E1, E2, and E3, but we do not have access to proof X one way or the other, then the rational probability estimate is the result of the Bayesian update P(H|E1,E2,E3). You do not get to say, "Well, we don't know whether X or ~X, so I'm going to throw E1, E2, and E3 out the window until you tell me about X." I cannot begin to describe how much that is not the way the laws of probability theory work. You do not get to screen off E1, E2, and E3 based on your ignorance of X!
Nor do you get to ignore the arguments that influence the prior probability of H - the standard science by which, ceteris paribus and without anything unknown at work, carbon dioxide is a greenhouse gas and ought to make the Earth hotter.
Nor can you hold up the nonobservation of your particular proof X as a triumphant refutation. If we had time cameras and could look into the past, then indeed, the fact that no one had ever "seen with their own eyes" primates evolving into humans would refute the hypothesis. But, given that time cameras don't exist, then assuming evolution to be true we don't expect anyone to have witnessed humans evolving from apes with our own eyes, for the laws of natural selection require that this have happened far in the distant past. And so, once you have updated on the fact that time cameras don't exist - computed P(Evolution|~Camera) - and the fact that time cameras don't exist hardly seems to refute the theory of evolution - then you obtain no further evidence by observing ~Video, i.e., P(Evolution|~Video,~Camera) = P(Evolution|~Camera). In slogan-form, "The absence of unobtainable proof is not even weak evidence of absence." See appendix for details.
(And while we're on the subject, yes, the laws of probability theory are laws, rather than suggestions. It is like something the teacher tells you, okay? If you're going to ignore the Bayesian update you logically have to perform when you see a new piece of evidence, you might as well ignore outright mathematical proofs. I see no reason why it's any less epistemically sinful to ignore probabilities than to ignore certainties.)
Throwing E1, E2 and E3 out the window, and ignoring the prior probability of H, because you haven't seen unobtainable proof x; or holding up the nonobservation of X as a triumphant refutation, when you couldn't reasonably expect to see X even given that the underlying theory is true; all this is more than just a formal probability-theoretic mistake. It is logically rude.
After all - in the absence of your unobtainable particular proof, there may be plenty of other arguments by which you can hope to figure out whether you live in a world where the hypothesis of interest is true, or alternatively false. It takes work to provide you with those arguments. It takes work to provide you with extrapolations of existing knowledge to prior probabilities, and items of evidence with which to update those prior probabilities, to form a prediction about the unseen. Someone who does the work to provide those arguments is doing the best they can by you; throwing the arguments out the window is not just irrational, but logically rude.
And I emphasize this, because it seems to me that the underlying metaphor of demanding particular proof is to say as if, "You are supposed to provide me with a video of apes evolving into humans, I am entitled to see it with my own eyes, and it is your responsibility to make that happen; and if you do not provide me with that particular proof, you are deficient in your duties of argument, and I have no obligation to believe you." And this is, in the first place, bad math as probability theory. And it is, in the second place, an attitude of trying to be defensible rather than accurate, the attitude of someone who wants to be allowed to retain the beliefs they have, and not the attitude of someone who is honestly curious and trying to figure out which possible world they live in, by whatever signs are available. But if these considerations do not move you, then even in terms of the original and flawed metaphor, you are in the wrong: you are entitled to arguments, but not that particular proof.
Ignoring someone's hard work to provide you with the arguments you need - the extrapolations from existing knowledge to make predictions about events not yet observed, the items of evidence that are suggestive even if not definite and that fit some possible worlds better than others - and instead demanding proof they can't possibly give you, proof they couldn't be expected to provide even if they were right - that is logically rude. It is invalid as probability theory, foolish on the face of it, and logically rude.
And of course if you go so far as to act smug about the absence of an unobtainable proof, or chide the other for their credulity, then you have crossed the line into outright ordinary rudeness as well.
It is likewise a madness of decision theory to hold off pending positive proof until it's too late to do anything; the whole point of decision theory is to choose under conditions of uncertainty, and that is not how the expected value of information is likely to work out. Or in terms of plain common sense: There are signs and portents, smoke alarms and hot doorknobs, by which you can hope to determine whether your house is on fire before your face melts off your skull; and to delay leaving the house until after your face melts off, because only this is the positive and particular proof that you demand, is decision-theoretical insanity. It doesn't matter if you cloak your demand for that unobtainable proof under the heading of scientific procedure, saying, "These are the proofs you could not obtain even if you were right, which I know you will not be able to obtain until the time for action has long passed, which surely any scientist would demand before confirming your proposition as a scientific truth." It's still nuts.
Since this post has already gotten long, I've moved some details of probability theory, the subtext on cryonics, the sub-subtext on molecular nanotechnology, and the sub-sub-subtext on Artificial Intelligence, into:
Demands for Particular Proof: Appendices.