Mainstream climate scientists believe there’s such a thing as Downwelling Longwave Radiation (DLWR) originating primarily from Greenhouse Gases. Does it actually exist? Maybe, but I haven’t seen any compelling evidence for it.
Isn’t it obvious what they did? How could there be two radiation dead ends? Nothing works like this in reality. If you were to place a resister into a circuit, would the electrons suddenly flow from two sides into the resister? No, the flow is one way. The flow is always from the generally hotter surface to the colder atmosphere. Downwelling Longwave Radiation is ACTUALLY Upwelling-from-Pyrgeometer Longwave Radiation. There are two Ups, not one Up/one Down.
You may have seen something like this “proving” DLWR exists:
Why is this evidence no good? Because they use special instruments that are super-cooled! (Paper):
“Both instruments incorporated a liquid-nitrogen-cooled, narrow-band, MCT detector …”
Well yes, heat flows from hot to cold, so naturally, when you use super-cooled instruments and pretend that represents Earth’s surface, you will see a lot of Downwelling Radiation – otherwise it doesn’t exist.
Do people spontaneously get swallowed up by the Earth? No, but if you pretend the Grand Canyon represents typical Earth, then sure, people will get “swallowed up” as they try to move across it.
I think most rational people can agree that there is generally no Downwelling radiation from atmosphere to surface. So why does NASA pretend that the atmosphere provides the surface with 158 or 340 W/m² (contradiction exposed here), when it usually provides NOTHING?