Some nonscientists who heard about the Laws of Thermodynamics in high school, but didn't understand them, don't believe in so-called (admittedly poorly named!) “Greenhouse Warming,” because they think it must violate the 2nd Law of Thermodynamics. Some of them even deny the existence of downwelling longwave infrared (“LW IR”) radiation emitted by “greenhouse gases” (GHGs) in the atmosphere.
They are wrong. LW IR “backradiation” is readily measured, and its existence and absorption do not violate the 2nd Law of Thermodynamics.
The main sources of such confusion are an outfit calling themselves Principia Scientific International (PSI), a book they wrote called, “Slaying the Sky-Dragons,” and a Mr. Joe Postma. They insist that the greenhouse effect (“GHE”) cannot be real because a colder thing cannot heat a warmer thing. That's wrong.
Their stubborn confusion inspired me to wax poetic. With apologies to the late, great Ogden Nash, I give you:
If you want to learn how GHGs warm the Earth, and why the “Sky-Dragon Slayers” are wrong, here are some good sources of information:
Roy Spencer:
Anthony Watts:
Steve Carson:
Judith Curry:
Will Happer:
and my resource list: