Steve Koonin has emerged from the woodpile to defend his clowning in the APS POPA process and the Wall Street Journal on Judith Curry's blog.
Alerted by Willard and ATTP, the bunnies crossed their ears and read Koonin's lament, only to see
An even simpler indication of the percentish influence is to note that a 3 C mean global surface temperature increase on a base of 288 K is also about a 1% effect.This is beneath contempt. Without greenhouse gases the surface of the earth would be near 255 K on a simple calculation known to all, and indeed, ~255 K is the measured temperature of the Moon's surface. Arthur Smith had a complete discussion of this on arXiv a while ago. Eli would not be surprised to see such a lights out statement from Willard Tony or the good Biship, indeed it would be a step up in the usual. However, by rumor, while it is true that the temperature of the surface would go to 3K or so if the sun did blow out, that is not scheduled
But it is all of a piece. Let the Bunnies look at Dr. Koonin's take on forcing from CO2, which, of course is logarithmic.
An alternative way of seeing the physical smallness of anthropogenic influences is to look at how the long-wave absorptivity of the clear sky increases with CO2 concentration – this is the physical input to GCMs that varies directly. Figure 4 from Harde shows that a doubling from the pre-industrial 280 ppm to 560 ppm increases the absorptivity by about 1% on a base of 82%, or, again a percentish shift. An even simpler indication of the percentish influence is to note that a 3 C mean global surface temperature increase on a base of 288 K is also about a 1% effect.