[cogitator]

After all, it's not like we have an example from the past in which man pumped CO2 into the atmosphere at our current rate, raising the atmospheric concentration to its current level (that is, raising it above the quasiequilibrium level and potentially making CO2 become a forcing element, not reactive).

The best natural analogue, well out of reach of ice core but not oceanic sediment cores, is the Paleocene-Eocene Thermal Maximum. It occurred over much longer time-scales, but it did show the expected cause-and-effect relationship.

[Gondring]

I thought that the latest on the PETM was that the temperature signal preceded.