Ivan Seeking said:
I was not aware that Vanesch was a climate scientist. The definitive reference is the IPCC, and they claim 90% confidence in AGW; and that the debate about GW is over entirely. Without meaning to beat up on Vanesch who specified that he is not a climate expert, this is no different than any other subject, so why do the opinions of non-experts suddenly matter? We don't allow this in any other forum.
I don't claim to be a climate expert, but I do claim to be a scientist, and hence an "expert" on the scientific method. Climate science is an applied science, in that it doesn't put into doubt any fundamental knowledge of physics, chemistry or biology, but just builds upon it. As such, facts beyond doubt should be arguable from that basic knowledge, and from empirical data, and you can't find that watertight argument. For something to be established *beyond doubt*, the argument has to be watertight. The only thing left for skeptics would then be to attack the fundamentals, which would correspond to desperate crackpottery.
There are two ways to establish a scientific fact beyond doubt: overwhelming empirical evidence, or watertight theoretical modelling based upon undisputable basic facts. We are trying to establish a cause-effect relationship, which can empirically only be established by:
1) having a strong correlation between cause and effect
2) altering "randomly" the cause, and still observing the correlation.
Given that we've not yet diminished human CO2 production, and observed a corresponding decrease of atmospheric CO2 and a corresponding decrease in global temperature, it is fundamentally impossible to establish a cause-effect relationship based upon empirical observation alone, in principle. We can at most observe a strong correlation between human CO2 production, atmospheric CO2 content and temperature rise, but there's nothing that makes this correlation in a cause-effect relationship as long as we haven't introduced random variation of the expected cause. As such, it is in principle impossible to find any such cause-effect purely by empirical observation alone.
This WILL be possible if we start dimishing our CO2 production, over about 100 years or so. THEN there will be a strong case for the empirical establishment of cause-effect. But not before. No correlation can do so. There can be a common cause.
The modeling is as of now by far not "watertight" enough to be a reasoning "beyond doubt" (meaning, if the data do not correspond to the model, that means that one or other fundamental input is wrong, in a "reductio ad absurdum" argument).
You only enter the "established beyond doubt" case, when in order to be able to find a loophole to put the statement in doubt, you have to wrinkle yourself in such crazy forms that you have an avalanche of statements you have to put in doubt.
Example: statement: "diamond is made of carbon in a "diamond" lattice." If you want to put that statement in doubt, you have to explain diffraction patterns of X-rays differently than through normal EM propagation, which puts in doubt Maxwell's equations, which...
You also have to put in doubt a lot of quantum chemistry, which calculates correctly the bond lengths, you have to put in doubt part of thermodynamics concerning the measurements of internal energy and entropy and so on ; in other words, in order to be able to put in doubt the statement "diamond is made of carbon in a diamond lattice", you get such an overwhelming amount of fundamental knowledge that you have to put in doubt, that this is crazy. Hence, "diamond is made of carbon in a "diamond" lattice." is a statement that can be assumed scientifically established beyond doubt.
I'm simply saying that AGW hasn't reached that level of scientific certainty. In fact, when you - as an intellectual exercise - put AGW in doubt, there's not much else that you need to put in doubt. Now, that doesn't mean that you have to. Like all people on the frontier of science, you have to make educated guesses of what's probably true, and you work your way in trying to prove and disprove it. That work is ongoing right now. Personally, I think it might very well be true. And as such, as a scientist, I would have liked to see that climatologists try to prove it WRONG. Try to find all possible explanations that show that AGW is NOT true. If they can then only come up with totally crazy schemes, THEN I would consider AGW as "scientifically established". In the mean time, I think it is probably true - that's what I call "it's suggestive". If I have to make a bet, I would say, AGW is true. But if it is "scientifically established" then there's no bet to make. Like there's no bet to make on the crystal structure of diamond.
I'm as such, not disputing AGW by itself, I'm disputing the - IMO - doubtful scientific attitude in the business.
It is one thing to recognize that we have 10% uncertainty, but this is hardly a wide-open question, and I don't know how much certainty is even possible; for all that we know, this may be as good as it can get under an circumstances. Also, the two countries with the most to lose by making a more bold statement - the US and China - were the only groups that objected to a declaration of 95% confidence in the AGW model. So if you want to talk about bias, there you go.
Well, if the confidence interval were a scientifically established number, then there would be no discussion about it (and it wouldn't be a round number such as 90% or 95%).
And as Vanesch pointed out, nothing is over, there are no conclusive results.
