Canuck

I'm sorry - but I was under the impression that climate models only include solar irradiance, not solar activity. Do you have a link that describes how solar activity (sun spots and such) are incorporated into GCMs?

Thanks for merging my thread with this one. Ok - so some warming starts the process (talking historically), then CO2 warming gets added to the mix 800 years later. Has there been any work done looking specifically for a increase in the rate of warming at t-800 +-200 that could be explained by the CO2 induced warming? I'm guessing there would have to be - since it's highly improbable that the initial process would cease at the same time the CO2 warming started.

Hi there everybody - first poster here. Not sure if this is the right place to post this - but oh well. I've recently started doing some research on global warming, and have come across one aspect of it that's troubling me. I'm wondering if anybody can shed some light on this for me. First of all, here's a couple of disclaimers, just so people don't immediately jump on me like I'm some sort of heretic. 1) I have no reason, not to believe the earth is warming 2) I have no reason, not to believe that CO2 is playing some role in this. 3) I do believe we should be reducing our reliance on fossil fuels - even without taking into consideration global warming. Now, my question. It relates to the vostok ice cores, and how the information contained within them has been used to infer the CO2/temperature cause/effect relationship. There's obviously a strong correlation between CO2 and temperature going back some 650 000 years http://www.daviesand.com/Choices/Precautionary_Planning/New_Data/ However, like we all know, correlation does not equal causation. Some other studies have studied the same data from the vostok ice cores, from a temporal aspect, and found that increases in temperature actually lead increases in CO2 by approximately 800 years (+-200y). This lead was found to occur in both the rise and the fall of temperatures. Here are abstracts to the studies (they include the conclusions) http://www.sciencemag.org/cgi/content/abstract/283/5408/1712 and http://www.sciencemag.org/cgi/content/abstract/299/5613/1728 Obviously this calls into question the assumption that CO2 was the causation factor for temperature increases.......historically speaking. Does this prove CO2 is not the primary driver for today's temperature increase? No, but it certainly doesn't help it's cause, since that ice core data has been held up as proof of the CO2/temperature relationship. So my question is, has there ever been a study that somebody is aware of, that has attempted to calculate, from first principles (so without relying on historical data), the portion of current warming that is caused only by CO2? I'm guessing that this should be possible, given some thermodynamics equations and such. Anybody? Or am I out to lunch?