I stumbled across a site where someone decided to test the predictions made by the IPCC in 1990 and compare them to the collected temperature data. The result?
Following a gradual rise of about 0.2 degrees from 1990 to 2000, global temperatures have stopped increasing and have actually fallen slightly. The only IPCC prediction which remains consistent with the current data is the lower prediction of a 0.7 degree rise from 1990 to 2030. The “Best” IPCC estimate and the higher 1.5 degree rise are ruled out by the data.
CO2 levels in the atmosphere have continued to rise over the last 10 years (see overlay to temperature comparison below in Figure 3) but temperatures have not risen since 2000. This implies that CO2 is not the main driver of global temperatures on these time periods and that other natural mechanisms are at least as important. No evidence of any positive temperature feedback with increasing CO2 levels is found.
So even the IPCC’s lowest result didn’t even come to pass. The period in the 2000s is particularly interesting because CO2 levels have continued to go up, but the temperature ends up loafing around, even dropping slightly.