On Wednesday, November 28, 2018 at 7:13:24 PM UTC-7, Quadibloc wrote:

So I presume that Modtran does already account for such things as the fact that
an increase in the carbon dioxide level will warm the planet, leading to an
increase in water vapor, which will warm the planet some more, leading to a
further increase in water vapor... while theoretically, in a mathematical sense,
the cycle would have an infinite number of steps, each step is smaller than the
one before.

Perhaps it *can* do so, but this climate skeptic web site

https://wattsupwiththat.com/2014/04/...dtran-mystery/

notes that it doesn't _have_ to; it claims that advocates of global warming as a
problem have used a higher value for instantaneous forcing than does Modtran.

If so, then they may indeed be mistaken.

But I would have thought that what _matters_, if one is concerned about the
ultimate consequence of reaching a certain carbon dioxide concentration in the
atmosphere, is the *equilibrium* forcing, not the instantaneous forcing. Which
is much higher.

John Savard