Sorry, Badger, I'm being a jerk. My excuse -- not a good reason, just an excuse -- is that I just had exactly the same argument with D.C., over on Amazon, and it left me with zero patience for such nonsense. He stubbornly insisted, in disregard of all evidence, that, "Atmospheric radiation from a colder atmosphere cannot heat a surface that is already warmer." That's crap theory, no better than chemtrails. (Digression: Amazon has deleted all of D.C.'s comments, but before they did I saved a copy of the entire main thread. It got weirder and weirder, as it progressed. By the end D.C. was insisting that when diesel engines compress air in their cylinders the compression doesn't heat the air, except a little bit by "friction," because the laws of thermodynamics prohibit it. If anyone wants to read a whole lot of crazy nonsense, together with repeated fruitless attempts by several different people, including me, to help him understand it, then email me, and I'll send it to you.) Dr. Roy Spencer has made many patient attempts to explain what is wrong with the Slayers' claims, including their claim that radiation from cooler sources cannot heat warmer destinations: http://www.drroyspencer.com/2010/07/yes-virginia-cooler-objects-can-make-warmer-objects-even-warmer-still/ http://www.drroyspencer.com/2014/04/can-infrared-radiation-warm-a-water-body/ Here is my weaker attempt to explain of how radiation from CO2 in the cooler atmosphere can warm the already warmer earth below: https://wattsupwiththat.com/2016/10/25/mit-traditional-incandescent-light-bulbs-reinvented-may-make-a-comeback/#comment-2327676 Speaking of crap theory, no better than chemtrails, recall this wisdom from Peter Drucker: "If you can't quantify it, you don't understand it." So if you want to understand why "gravity induced temperature gradient" theory is also crap theory, no better than chemtrails, you could start by reading my attempt to work through the numbers, last Fall, here: https://wattsupwiththat.com/2016/09/14/climate-skeptics-behaving-badly/comment-page-1/#comment-2300871