Gavin Schmidt is the current head of NASA GISS. In 2010, he wrote:
We quantify the impact of each individual absorber in the total effect by examining the net amount of long‐wave radiation absorbed in the atmosphere (G, global annual mean surface upwelling LW minus the TOA LW upwelling flux) [Raval and Ramanathan, 1989; Stephens and Greenwald, 1991]. This is zero in the absence of any long‐wave absorbers, and around 155 W/m2 in the present‐day atmosphere [Kiehl and Trenberth, 1997]. This reduction in outgoing LW flux drives the 33°C greenhouse effect defined above …
Kiehl & Trenberth (the creators of the “official” energy budget), in 1997, wrote (PDF) that:
values for the net surface shortwave flux range from 154 to 174 W/m2
Clearly both are saying that in their conception of the greenhouse effect, greenhouse gases (GHGs) add something like 155 W/m2 beyond what the sun can do.
If that is the case, then why does NASA’s official Energy Budget (also developed by Kiehl & Trenberth) try to imply something else … something extra?
As you can see in the above diagram from NASA, they are trying to imply that greenhouse gases provide 340.3 W/m2. Isn’t that what they are doing? Why else have the label “Greenhouse Gases” in green hovering over “back radiation 340.3 W/m2” with green arrows pointing down?
Indeed, they are trying to perpetrate a subtle fraud. How do they accomplish this?
Very simple! They add the values encircled in red to the true value encircled in green.
340.3 – 77.1 – 18.4 – 86.4 = 158.4 (i.e, around 155 W/m2) is the true value.
So which is it, NASA? Do GHGs emit 158.4 W/m2 or do they emit 340.3 W/m2? Clearly the former. Now why would NASA attempt such a blatant obfuscation? If they are lying about such small things, what else could they be lying about?