Ok, I’ll bite - sure. Why do you suppose that is?
What does your previous question have to do with this?
So, you think that all this can be tested better than it currently is?
LilShieste
I think we have a white flag.
“Although I present no evidence that my position is correct, because you can’t prove I am wrong, I am right.”
And which side is like religion?
I have no idea. But it shows the problem with your argument. By your reasoning, the temperature drops I cited could not have been the result of natural fluctuations.
Right?
Because the obvious explanation for the apparently unprecedented temperature drops I cited is the fact that we don’t have the same kind of temperature data for past centures that we do for the past 100 years or so.
I don’t know.
I already answered that. Plenty. I might ask the modelers to run it on new data if I didn’t trust them, but that’s a different story, plus you’d find out a lot faster.
To the model, what possible difference is there between testing against data in our past but the model’s future, or testing against data in our future?
And that depends on the results you get from the model.
Let’s go back to your stock market model. It looked like you had three results - down > 5%, up > 5%, essentially unchanged ( < 5% swing.) I’d have to look it up, but my impression is that due to random fluctuations the market almost always swings > 5% during a year, so you’re close to 2 outcomes. Given that, the probability of the results of any model for any reasonable time period being due to chance is pretty high, and I wouldn’t buy a model with this kind of outcome, since it is impossible to test rigorously. A model giving closing prices on a number of industry segments, to with 5%, say, would have a lot more possible outcomes, and be much easier to test to my satisfaction.
Just from reading news articles, I think AGW models don’t just say if temperatures are going up, but give specific predictions in a number of areas. In that, they are very testable. I’m sure the experts will tell me if I’m wrong.
Basically this is the case as I see it, at least at this moment of time with current technology.
I’m not sure if any scientific conclusion can be accepted as long as so much politics is involved at this time.
For one thing, survivor bias.
Like I said before, one could generate 100 stock market models based on data from 1990 to 2000, and then “test” the models against data from 2000 to 2006. Statistically, one can expect that 1 or 2 of those models will fit well with the more recent data. But you’d be a fool to pay anything for the two surviving models.
Another problem is that when people are post-dicting, it’s hard to know that they aren’t cooking the books. If somebody publishes a model that post-dicts temperature for the last 10 years, there’s no way to know that there aren’t 100 failed models in the guy’s trash can.
So the conclusion you draw from this is that since global warming is such a politically-charged issue, we should do nothing about it (as all data is immediately suspect)?
You do realize that by doing nothing, you’ve chosen a side, right?
Thanks for your answers. What I am trying to understand is, from your perspective, what is the ‘next step’ for society? Continue with our regularly scheduled human activity as if AGW is definitely not a threat? Modify our behavior just in case it turns out to be a threat? Keep investigating in the meantime? Stop investigating because it’s a useless effort?
I already proposed a test along these lines:
Take Hansen’s model from 1988. I’m choosing this one because it was very promient at the time. Re-compile the source code using what we know now about emissions. (Assuming that the source code has been published.) See how well it matches the temperature data.
Choosing 1 (and only 1) prominent model eliminates the possibility of survivor bias. And if the source code has been published, there’s no way for anyone to go back and tweak the model.
How much politics was involved when all the data began building up back in the 70’s and 80’s? You know, when nobody outside of Tenessee had ever heard of Al Gore and 95% of the population had never heard of global warming?
This was a scientific issue for decades before politics became involved.
What were the motivations of the scientists in the mid 1980’s when they were first drawing these conclusions?
I’d like an honest answer to that question, please.
Since no one has produced evidence that climate models are put together that way, I have to say your example is irrelevant.
And Edison had thousands of his failed light bulbs in the trash can, but I don’t think anyone acused him of cooking the books.*
- Until the invention of the easy bake oven and bad kids that is…
Pielke Jr. is confused (which is not surprising since he is not a climate scientist, although his father is). The point is that one can convert the emissions scenarios intto “radiative forcings” which are what essentially end up mattering. It doesn’t matter if the CO2 was less and the CH4 was more than in Scenario B if we know the relative radiative forcings over time that Hansen’s model assumed (which we know because he assumed a certain emissions scenario) and what radiative forcings over time actually came to pass. That is what Gavin has done in that RealClimate piece.
Well, my credentials are really irrelevant since I am not for the most part trying to argue that you should believe what I say on climate science on the basis of my credentials. (But, for the record, I am a PhD physicist who does computational modeling for a living…although not climate modeling. Keeping up on climate science is just a hobby for me.)
What I am talking about are the conclusions of major scientific bodies who have evaluated the science, like the IPCC, the U.S. National Academy of Sciences (NAS) and their analogous societies in many of the major countries of the world (Canada, Britain, France, Italy, Russia, China, …) who issued this joint statement, and the American Association for the Advancement of Science (AAAS). Note that the NAS has in its charter the specific purpose of evaluating scientific issues that have public policy implications for the U.S. government.
and
Since your posts are basically the same I’ll try to answer them together. What would you do if someone told you that the world was going to end (or experenance extreme hardship) unless we raise the price of everything so the poor will starve and the lower middle class will become the new poor, and will give even more control over common man to those in power. But as far as you can see the study is invalid?
Wouldn’t it be immoral to accept such a study that if we follow their suggestion will potentially kill millions around the world and cause loss of liberties for many more?
The next step, as I see it should be going away from fossil fuels to nuke power, not because of AGW but because it’s a more reliable source of energy then oil from unstable areas of the world, though coal is also useful in that too. I personally would like to see electric power prices fall, and the only way to do that is to increase supply. With cheap electricity that should help shift autos from gasoline to more electric based.
Research in AGW can continue, but I would not like to see any burden shifted onto the poor in our country or around the world. Perhaps high tech antiglobal warming methods can be researched (solar shade?), and can be launched if it does prove to be true (or it’s getting really hot). Maybe it can be made reflective incase it’s really global cooling and it can be used to focus more sunlight on earth.
I do find it comical that it seems everytime that Al Gore has a speech in my area that it seems to happen during a extreme cold snap, including the coldest day of the year/month 2 times IIRC. Whatever side of the issue you are on it does show to me that God has a sense of humor.
Yes to protect the poor, and to protect the common man from ever increasing government interference in their lives.
Well… I have to say that this is the first time I’ve ever heard anyone frame this issue as a right-wing conspiracy. At least you’re being original.
We know that there are a lot of climate models out there. And we know that many are “tested” by comparing them with historical data. And we know that it’s human nature to call more attention to our successes than our failures.
That’s certainly enough to be skeptical of post-diction as a means of testing.
As far as I know, Edison wasn’t trying to justify anything with post-diction. If somebody claims they can predict the future, and points to past predictions that were correct, we are naturally skeptical.
But it seems that by your own statements, you are not in a position to judge the AGW hypothesis.
If you are not a climate scientist, why should anyone accept any of this?
There is survivor bias only if the number of models is large relative to the number of outcomes. Like I said, survivor bias is a factor in your simple market models. If the number of outcomes is very large, then survivor bias will not be a factor. Since the space of possible models is big, you want to use a type of natural selection to search it, which involves choosing the models whose predictions are closest to the real data, and revising them. But not, of course, by building in fudge factors so that the results do match the test data. That’s what computer companies do with compilers to get good benchmark results.
But that is what falsification is all about. You come up with a hypothesis, (or model,) test it, and if it is falsified then you throw it out. I have seen criticisms that more failures aren’t published, to help people avoid failing in the same way, but there is limited space, and writing takes a lot of time.
What should people with bad models do with them besides toss them?