ElfDude wrote:Devil's Advocate wrote:I didn't realise just how ignorant Crichton is.
Climate and weather are not the same thing.
Umm... yeah... but I always thought they were related...
Sure, but it's analogous to the relationship between the size of a tree and that of one of its leaves.
You can't tell how big the tree is just by examining a leaf.
But when I saw that you'd posted, I was kinda looking forward to your insightful defense of the use of computer models. No biggie though.
Ok, let's go through the quote, and let's bear in mind that the computer models I've been talking about up to this point have been used to analyse the climate change
that has already happened, and not how good they are for predicting the situation 100 years from now....
Crichton wrote:To an outsider, the most significant innovation in the global warming controversy is the overt reliance that is being placed on models.
Models are of vital importance to all branches of science. I'm disappointed that he doesn't seem to know this.
Back in the days of nuclear winter, computer models were invoked to add weight to a conclusion: "These results are derived with the help of a computer model."
Um, so what? There was no nuclear war, so we thankfully don't know how good those models were. But we also have no reason to think they're wrong.
But now large-scale computer models are seen as generating data in themselves. No longer are models judged by how well they reproduce data from the real world-increasingly, models provide the data.
No. As you'll see from my previous posts, the models are compared to
measured data.
What you can do with a model that can't be done with reality is exclude anthropogenic factors. If you do that, the models don't match reality. If you don't exclude the anthropogenic stuff, the models
do match the measured data.
As if they were themselves a reality. And indeed they are, when we are projecting forward. There can be no observational data about the year 2100. There are only model runs.
And all the modellers are perfectly well aware of that. That's why computer modelling is very much an ongoing project.
This fascination with computer models is something I understand very well. Richard Feynmann called it a disease. I fear he is right. Because only if you spend a lot of time looking at a computer screen can you arrive at the complex point where the global warming debate now stands.
Utter falsehood. Global warming is a measured, observed phenomenon.
Nobody believes a weather prediction twelve hours ahead. Now we're asked to believe a prediction that goes out 100 years into the future? And make financial investments based on that prediction? Has everybody lost their minds?
Conflating weather and climate: see above.
Stepping back, I have to say the arrogance of the modelmakers is breathtaking. There have been, in every century, scientists who say they know it all.
Possibly. But no climate scientist I've ever heard of is amongst that small number.
Since climate may be a chaotic system-no one is sure-these predictions are inherently doubtful, to be polite.
Weather is chaotic. Climate is predictable.
But more to the point, even if the models get the science spot-on, they can never get the sociology. To predict anything about the world a hundred years from now is simply absurd.
But it's much more reasonable to predict carbon dioxide emissions for a decade or two hence. That's all anyone is doing, and it's all that is needed to see how things will get. Even at
current emission rates, we're in trouble. It may be that carbon emissions will reduce in a century, even if there's no concerted effort to make that happen. But without such an effort, and probably even with it, things will get a lot worse before they get any better.
Look: If I was selling stock in a company that I told you would be profitable in 2100, would you buy it? Or would you think the idea was so crazy that it must be a scam?
Bad analogy. The economy is a lot more volatile than the climate. Climate can be modelled pretty well; the only variables that can't be included are volcanic and human activity.
The rest of the article is in more of the prediction vein.
