@pschwede BTW just to be transparent there ARE actually some points in that chart where you are right, temperature causes the change of CO2 rather than CO2 causes the change in temp. The analysis has shown that. Thing is we know why in that case.

It happened something like this.. At first CO2 rose due to volcanic activity and this caused the temp to rise. But once the temperature reached a specific critical point it caused a release of CO2 from the oceans (after a very long delay as it took time for the oceans to warm up at deep depths). This rise in temperature caused a chemical reaction to occur which caused the oceans to release massive CO2 itself and thus perpetuate the temperature rise even more.

We can prove this due to fossile record, and CO2 levels in the ocean along with measuring the chemicals that reacted to generated the CO2 in the substrate.

So in this one example, which resulted in an extinction level event, you can say that there was temperature causing CO2 rise rather thant he other way around. But as i said this is the exception rather than the rule.