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Yes, but it's not like the 1990 model was massively wrong or something. The (now historical) observations are riding the lower end of the predicted range from 1

Yes, but it's not like the 1990 model was massively wrong or something. The (now historical) observations are riding the lower end of the predicted range from 1990, but even the low estimates still predict a 3C temperature rise by the end of the century. All models are wrong and some are useful. Even a 3C rise would be pretty bad. Just because some of the 6 or 7C predictions (high end of range) don't appear to be coming true we should just ignore the rest of the models?

pdonis 7y ago
> The (now historical) observations are riding the lower end of the predicted range from 1990 No, they're lower than the low end of the predicted range. Plus, the low end of the predicted range was based on assumed CO2 emissions that were significantly lower than what has actually occurred since then. So we have more CO2 than predicted and less warming than predicted even from the lower than actual CO2. > even the low estimates still predict a 3C temperature rise by the end of the century That's not 3C rise from where we are now. It's not even 3C rise from where we were in 1990. It's 3C rise from the "pre-industrial" temperature, i.e., the mid to late 1700s, i.e., in the middle of the Little Ice Age. Temperatures have already risen (largely due simply to coming out of the Little Ice Age) by about 1.6C since then, so that low estimate is about 1.4C rise from now to 2100. And, as noted, actual temperature rise is running below the low end estimate. We're looking at roughly a degree C rise in a century. The idea that humans cannot adapt to that so we have to spend trillions of dollars to stop emitting CO2 right now is laughable. > Just because some of the 6 or 7C predictions (high end of range) don't appear to be coming true we should just ignore the rest of the models? We should not be using the models to drive public policy decisions with multi-trillion dollar costs. They're simply not good enough for that.

pdonis 7y ago

> The (now historical) observations are riding the lower end of the predicted range from 1990 No, they're lower than the low end of the predicted range. Plus, the low end of the predicted range was based on assumed CO2 emissions that were significantly lower than what has actually occurred since then. So we have more CO2 than predicted and less warming than predicted even from the lower than actual CO2. > even the low estimates still predict a 3C temperature rise by the end of the century That's not 3C rise from where we are now. It's not even 3C rise from where we were in 1990. It's 3C rise from the "pre-industrial" temperature, i.e., the mid to late 1700s, i.e., in the middle of the Little Ice Age. Temperatures have already risen (largely due simply to coming out of the Little Ice Age) by about 1.6C since then, so that low estimate is about 1.4C rise from now to 2100. And, as noted, actual temperature rise is running below the low end estimate. We're looking at roughly a degree C rise in a century. The idea that humans cannot adapt to that so we have to spend trillions of dollars to stop emitting CO2 right now is laughable. > Just because some of the 6 or 7C predictions (high end of range) don't appear to be coming true we should just ignore the rest of the models? We should not be using the models to drive public policy decisions with multi-trillion dollar costs. They're simply not good enough for that.