1. What does the average temperature measure?
2. Does that mean: CO2 causes temperature changes, temperature changes influence CO2 levels, both are influenced by other factors in a similar fashion, or it is a coincidental correlation?
3. Does that mean it is not possible, or does it mean nobody understands the system well enough to accurately simulate it, or does it mean there is no money in simulations which don't achieve certain results, or perhaps the flawed understanding is coincidentally able to produce similar enough results when certain other assumptions are included?
4. Doesn't #3 imply that models are good at simulating climate trends? Are they? Do you understand how they work, and how they achieve their results?
1. Average planet-wide temperature.
2. CO2 causes temperatures to rise. We have known this since the nineteenth century.
3+4. Moot.
1. Temperature is a measure of the average kinetic energy in an ensemble of particles. The temperature of a glass of water refers to how energetic the molecules bouncing around inside the glass are on average. What is the average temperature of a glass of ice water and a cup of fresh coffee? What property of the ice water+fresh coffee system does that average temperature represent? Is there a way to measure average temperature? What property of the global oceanic/surface/atmospheric system does
that average temperature represent? "The average average kinetic energy of the ensemble of all gas, liquid, and solids on the planet?" What do changes in this average average kinetic energy mean? What effect if any does it have on the boundary conditions of the system?
2. It has been proposed that CO2 behaves in a way which for some reason is equated to a greenhouse, there are numerous problems with certain arguments drawn from this hypothesis. Several of these problems have been known since the 19th century. I've done experiments on this myself. Naturally they are hardly the final word, and I was mostly testing a different hypothesis, but it so happened that I could include a bit of exploration on the effects of CO2 on my apparatus, so I did. If you're curious send me a PM and I'll try to dig it back up, I had most of it on a failing hard drive so it's all scattered from the frantic transfer process, but if not that's cool too. I'm comfortable being doubted because science is a process, not something you can call "settled" in any way.
3+4. If models are used to justify policy and support political agendas in the guise of science, how are they moot?