CO2-driven global warming in not totally wrong, but nearly so. It is only good for 0.3 degrees from here to eternity. Emissions to date are worth 0.1 degrees, there will be another 0.2 degrees to 620 ppm and then only a further 0.1 degrees to when the effect peters out due to the logarithmic effect you dread so much. … you might be able to tell the difference between having your car’s air conditioner set at 21 degrees and having it at 22 degrees. But I very much doubt that you could detect a 0.4 degree difference. So there you are. CO2 is one less thing …to worry about, because the effect is so miniscule.
From the comments at Warwick Hughes' site
Wednesday, June 11, 2008
Here is a quote from David Archibald, that makes sense, I think.