billc writes “I think Lacis is wrong in that assertion and he basically admitted it.”
Thank you for the response, Bill, but if Andy Lacis is wrong (and I am convinced he is), then there is no way, using proper physics, that “Adding GHG increases the IR flux received at the surface” (to use out hostess’s phrase), can be translated into a change in surface temperature. It simply cannot be done. And if it cannot be done, then there is absolutely no basis whatsoever for any value of climate sensitivity. We simply have no idea whatsoever what number to ascribe to climate sensitivity. It is not that there is uncertainly as the what the number is. It is that physics cannot tell us anything about the number at all.