In article ,
says...

On Friday, June 8, 2018 at 5:06:00 AM UTC-6, Paul Schlyter wrote:

In article ,
says...

But ANYTHING that causes a temperature rise is amplified by water vapor,
including the solar constant variations.

Yes - but we cannot control the variations in the solar output.

Not the point: the point is that solar output variations are about the
same size as heat flux exhaust of MASSIVE changes in CO2 levels.

Btw the Maunder minimum (of solar activity) for some 70 years centered
around the year 1680 is believed to be an explanation for the Little
Ice Age around and after those years.

That's ONE explanation. The other is volcanic activity, but probably both.
The question is how much is attributed to each.

Why the Maunder minimum should contribute to global cooling was unexplained
until the CLOUD experiment demonstrated nucleation of clouds by cosmic rays
and the measurements that the cosmic ray flux has been increasing with the
abatement of the solar wind. After all, the solar constant INCREASES when
there are fewer sunspots.

No, it doesn't. You forget, or perhaps you are unaware of, the effect of
the solar faculae which also increase as the solar activity increases.
The net effect is that the solar output is slightly higher when the solar
activity is high.

CHeck the diagram over the solar output during three solar cycles, from
1975 to 2005: https://en.wikipedia.org/wiki/Solar_cycle#Solar

Near solar minimum the solar constant is 1365.5 W/m^2 and near solar
maximum it increases by one W/m^2 to 1366.5 W/m^2. On individual days
the solar constant varies somewhat more, but not much more.


Pruitt himself, of course, ought to be able to explain where he got
his ideas from.

I don't know what his justification is, but the MODTRAN app

Is MODTRAN also available as an app? Where can I download it?

I'm only aware of it as an online "app."

An app is run locally. A web page is not an app.

certainly
confirms his position when a doubling of the CO2 level, which will take
200 years, produces enough direct effect to rival solar constant
variations. Cloud cover has a VERY large effect, initially to reduce
heat flux into space, but long-term to produce cooling by increasing
earth's albedo.

The effect of cloud cover for the local albedo, reducing incoming light
and heat from the Sun to the ground, will be just as instantaneous as its
effect of reducing heat flux from below into space.

But clouds reduce the heat flux coming up from the surface.

No, they don't. But the clouds do radiate IR radiation back to the
ground. And since the clouds are cooler than the ground, the clouds also
reduce IR radiation out into space. Maybe that's what you meant.

I played with
different types of clouds and cumulus and altostratus reduced the outgoing
flux by about 30 W/m^2 while nimbostratus only reduced it by about 6 W/m^2.
So the effect of less power coming in is offset by more heat being retained,
but eventually, that heat leaks out and a new balance is reached. The
heat capacity of the earth delays the cooling effect.

Furthermore, the initial effect of increased cloudiness has a warming
effect, but the long-term trend is to lower temperature due to
decreased input from the sun.

Please explain why the clouds absorption and re-radiation of IR is more
instantaneous than their reflection of visible light. Both of them ought
to be just as instantaneous. When a cloud passes in front of the Sun,
you'll feel the reduced light and heat from the Sun immediately, not
several years later...

I was amazed how cool it got during the total eclipse last year. But that
or a cloud passing in front of the sun are LOCAL effects. And during the
night, cooling is restrained by cloud cover which traps the heat.

A well-known effect - no disagreement here. More clouds cools the ground
in daytime and warms it during night. That's why it can be so hot in
deserts during the day but then almost freezing at the following night.