But the hindcasting goes back a lot further than that. According to Kimstu’s citation, they’re checking for accuracy in the Holocene, last Millenium, etc.
I think the “could not have been known” seems like a pretty strict check on cheating, but these otherwise seem like reasonable criteria. Having skimmed Kimstu’s cite, I can’t say whether or not that is the case with the CMIP5 because the language is too technical for my small brain.
I wasn’t aware of that. Anyway, I doubt that the mainstream view changes much from year to year. And when it does change, I doubt it changes definitively on that time scale.
Well I think it’s important to be strict. A lot of people, perhaps a majority, will cheat (either consciously or subconsciously) if they think they can get away with it.
It’s sot of maddening to actually find out exactly what you are asking about. The modelers seem to claim that “of course” their models exactly predict the past, even to the point of showing dips due to volcanic eruptions, and rising temps from El Nino years.
The skeptics, being skeptical, tend to insist they also match the last 17 years of “climate” change, which none of them do. Not even close.
But then the modelers point out the wide error margins and because they actually are very wide, they claim the complete lack of rising temps was also predicted. It seems, to the untrained eye, that nothing will prove a model wrong.
Even if all the models are wrong, they aren’t “really” wrong, they just need to be adjusted, and it doesn’t matter that they failed to predict what happened, because science is self correcting, and they adjust the models after the fact because that is how science works.
Your average person shrugs the shoulders and scratches the head and since they are experts and all that, they must be right.
Since most people “know” global warming is happening, it must be happening. And if a model doesn’t get it right, it just needs fixing. It doesn’t mean there isn’t global warming, just because the records show no global warming. Since the science says it must be happening, and all the models agree, then global warming must be happening. It’s science.
It is a real problem that the thing we’re trying to predict cannot be reliably measured except over decades. It means that gold standard tests of our science won’t come around until its too late. But the question facing us is what does the most reliable data we have right now say, based on our best scientific theories, about where the climate is going in the next century. That science may be, by its very nature, impossible to get as close to certainty as, say, theories about early human migration or something else immediately falsifiable when a new discovery comes along. That doesn’t mean it isn’t science, or that it isn’t the best available prediction about what we should be doing.
I don’t think any mismatch between short-term trends and the models suggests the models aren’t the best available evidence. First, I’m not sure what you represent is true. And second, even if it is, I’m not especially troubled if the models fail to make precise, short-term predictions unless they claimed to be able to do so. I assume there is much more variability in any year or even any decade’s weather than there is in overall global climate trends.
Yes, how does anyone know about the “except over decades” part?
I mean, if a television psychic were to tell you that he cannot make short term predictions, but he can make extremely accurate predictions about events 30 years in the future, you would naturally be very skeptical. You would say “Gosh, it sure is convenient for you that we have to wait 30 years to test your claims.”
As far as I know, there’s no evidence at all that it’s easier to predict climate 30 years from now than 5 years from now.
Besides which, as Fx points out, one can go back and check old predictions. For example Hansen’s famous prediction from the 80s which turned out to be wrong.
Another thing about Hansen’s computer model: It matched history very well.
So presumably people like chronos would have accepted it as authoritative on the ground that it had been tested and passed the test. After all, Hansen is not an idiot, right?
Of course, ignore that climate scientists already point out that short term predictions are not the main point of climate science. And it is really silly to go back on what the vast majority of scientists already accept as the most likely explanation of the current warming.
There is a reason why Hansen continues to be recognized, what the false skeptics do not want others to know is that there are very good reasons why his. He was more accurate than the ones claiming that there was not going to be warming.
That is the funniest thing I have read in a while.
The vast majority of the models used over estimate temp increases by a large amount. link
There are more graphs showing the models overstate temps. Judith Curry covers this area well.
How anyone can claim that the climate models are solid over long periods when they haven’t been around long enough to verify the long term performance really confuses and baffles me. What baffles me even more is the response of the warmists. Instead of admitting the models at this time are off by a large amount, they resort to name calling. Calling people things like ‘false skeptics’ and the like.
The models, at this point, are not complex enough to be accurate. They don’t do clouds well. They don’t do rain or snow well. They don’t do dust well. They did do some curve fitting to make the models mimic the past but there is no reason to believe they will be accurate in the future.
Having said that, cleaner energy is a good thing. New energy sources are a good thing. But the world ain’t gonna melt any time soon.
Well they do it using the one of the favorite tactics of warmists: Ambiguity.
chronos asserted that the models had been “tested” but when I asked him questions about how this testing was actually done, he disappeared.
Well what choice do they have?
The predictions of doom and gloom hinge on the validity of climate models. So if the evidence calls those models into question, you must either reject the evidence or not be a warmist anymore.
I agree, the models are obviously wildly overfitted.
Also, besides ignoring the testing that is being done, the usual point from climate contrarians is that climate models need better verification and validation (V&V). There are reasons why they are wrong on that one and the most likely reason is that it would boggle down the current research, just what many powerful interests would like to see.
