Well, the basic problem is in the decade when emissions increased over 45% the GHG forcing increased 0.2 W/m2 from 22 PPM more CO2.
Projecting that backward GHG is responsible for about 1.05 W/m2 to date.since 1900 (115 years).
The IPCC talks “limiting” the forcing to 6 W/m2 by 2100 and contends it could exceed 12 W/m2 by 2100 without drastic action.
Even if (a big if) we project the 0.2 W/m2 forward and assume the effect is linear not logrithmic that is only about 1.7 W/m2 more forcing.
Someone is crazy. The IPCC and their adherents need to generate some defensible projections. We can achieve the IPCC goal by doing nothing.
I guess Dr. Curry is right – we should shutter the IPCC, their work is done. We don’t need to discuss emissions in the post 2100 period – we will be out of fuel.