Read here. The climate modelers employed by NASA, the IPCC, the Met Office and etc., all claim that their models indicate a temperature increase of 2.5°C+ due to a doubling of CO2 (climate sensitivity). Yet when the model results are actually analyzed by experts, the climate sensitivity is likely less than half this alarmist claim.
This analysis done by Willis Eschenbach clearly shows that future temperatures for year 2100 being predicted by government-funded climate agencies have no basis in real-world circumstances, or even their own virtual reality fantasies. (This is probably why the Mayor of London is now supporting the leading UK skeptic versus the incredibly failed climate modelers of the UK's Met Office.)
(click on image to enlarge)
Another key finding by Willis is the built-in linear warming that the NASA model exhibits. Literally, no matter what level of CO2 exists, the NASA model will automatically increase global temperatures.
Did we say worthless, yet?