We won't live to see any of those things happen except maybe number 3 (although it could be more specific, i.e. which data or index shows the cooling trend and

We won't live to see any of those things happen except maybe number 3 (although it could be more specific, i.e. which data or index shows the cooling trend and for how long). And I think you may have missed my point. The hypothetical evidence you listed is mostly "proof of X" and "confirmation of Y" which suggests we disagree about how science works. I'm of the opinion that science does not advance by proving new theories correct, it advances by proving old theories incorrect. A new theory that cannot itself be proven incorrect is not scientific. The empirical evidence you have suggested with number 3 is one possible way to falsify the AGW theory, but it is somewhat vague and might mean waiting for a long time. Additionally, without the AGW theory we have no good reason to expect either warming or cooling in particular, so either one is not what Popper called a "risky prediction". I get the impression that you want me to go along with political action and engineering projects that I don't agree with. Perhaps you will continue to do so until some as yet unspecified temperature measurement shows a cooling trend for some as yet unspecified period of time, or we are both dead. From my perspective the theory has not made any risky predictions, and that has to happen before we can speak of confirming it. The situation is fundamentally biased against the activist politics. Not surprisingly, lots of the same activists have been trying to declare Popper "obsolete" for some time. I encourage you to read his essay and consider for yourself: http://www.stephenjaygould.org/ctrl/popper_falsification.html http://www.stephenjaygould.org/ctrl/popper_falsification.htm... "Confirmations should count only if they are the result of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an event which was incompatible with the theory — an event which would have refuted the theory." It is an interesting question though - what risky prediction can be or has been made based on the AGW theory? The "polar ice will disappear by X year" statements are the closest thing I can think of.