And [At?] equilibrium, the "limiting temperature", assuming a
black body, is the temperature that corresponds to radiating the
same amount of energy as the input. Anything else is nonsensical.
0) Requiring your arguments to be in accord with basic
physics is not nit picking.
1) The Earth is not in thermal equilibrium with the Sun.
If it were then it would be at the same temperature as the
surface of the Sun. The only reason life can exist on Earth is
because of the gradient caused by the Earth not being in thermal
equilibrium with the Sun.
2)
A black body is not the same thing as a perfect insulator. They
are opposites in a way. A perfect insulator would block all
radiative cooling (or else it would not be a very good insulator).
My point is that the limiting temperature is a function of the
insulating properties of the Earth. It is not an intrinsic
property of the strength of solar heating.
If you treat the Earth as a black body you are explicitly
ignoring all insulation effects. IOW you are ignoring
all greenhouse effects. In simple layman's terms, how hot
something gets when it is left out in the sun depends greatly
on how well it is insulated. Even the temperature inside a
conventional greenhouse is highly dependent on how well it
is insulated.
3) When you say a black body in equilibrium radiates the
same amount of energy it absorbs, you seem to be repeating the
definition of radiative forcing, not debunking it.
If you believe there is a limiting temperature to the
strength of solar heating that is much less than
the temperature of the surface of the Sun, please tell
us what that temperature limit is.
Neither of the fine articles linked to in the summary nor either
or your two references even mention radiative forcing.
If you have sources that don't conflict with basic physics
which debunk whatever it is you mean by radiative forcing
I would like to see them. Perhaps part of the problem is that
your definition of radiative forcing differs from the definition
given by the Wikipedia. So far you have given nothing more than
your opinion that the authors of the Nature article made a
serious (and probably job-threatening) mistake.