[Arragonis]

How about finding the something else first, before we run to the hills and hide ?

How much of the warming since the last ice-age should be attributed to CO2?

Since this is a science blog after all, I thought it would be appropriate to end this post with more solid science in it.

Overall, there was a 3.5°C degree increase taking place concurrently to a CO2 increase from 180 to 280 ppm. If the warming is entirely due to CO2, then the climate sensitivity should be ΔTx2 ~ 3.5°C/log2(280/180), or about 5.5°C per CO2 doubling. But as I explained above, this conclusions is not supported at all by the above correlation. However, it does imply that if anyone is calculating a probability distribution function for the temperature sensitivity to CO2, then they should cut it at 5.5°C, because it simply cannot be any larger than that.

On the other hand, my best estimate for the climate sensitivity, is that CO2 doubling should cause a 1 to 1.5°C temperature increase, or about 0.65 to 1°C for a 180 to 280 increase in the CO2. In other words, at most a quarter of the observed 3.5°C should have been caused by the CO2 feedback. The rest is something else.