The run-away greenhouse is impossible

Paul Schlyter wrote:
In article , Yousuf Khan wrote:

If one group of my cells died, then chances are that other groups of my
cells would die too, if they depended on them. And then my whole body
would die.

Not necessarily. Cells die in your body all the time. Your hair, which grows
all the time, consists mostly of dead cells. The very outermost part of
your skin also consists of dead cells, which protects the living cells
inside the skin and your body. As a matter of fact, almost all of your
body is renewed (= the cells are replaced by other cells) every 5 to 7
years or so (the figure varies depending on which part of the body).
As long as this is in equilibrium, your organism remains healthy. But if
your body would start to generate new cells in an uncontrolled way, you'll
get cancer. And if your body would generate too few new cells, you'll get
sick and die too - the latter often happens to old people.


Yes, I agree with that, I just didn't say it in so many words.

Yousuf Khan

In article ,
Andrew Usher writes:
The conventional explanation of the run-away greenhouse effect,
which produced the conditions we see on Venus today, is that
the evaporation of water vapor caused the temperature to rise so
high that the atmosphere became unbound.

This is not an explanation I've ever heard of.

1. The explanation I've heard involves 90 bars of carbon dioxide. Is
there any water vapor at all in the Venusian atmosphere?

2. For an atmosphere that is alleged to be "unbound," there seems to
be quite a lot of it.

I have seen a journal article that says the temperature would reach
'several thousand degrees' until the surface could 'radiate in the
visible'.

Reference? The highest possible temperature is the effective
temperature of the Sun divided by the square root of 2. This is just
conservation of energy for an imaginary atmosphere that is completely
transparent to visible light and completely opaque at longer
wavelengths. Of course no real atmosphere will be ideal in this
fashion.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
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On Jun 25, 3:05 pm, (Steve Willner) wrote:
In article ,
Andrew Usher writes:

The conventional explanation of the run-away greenhouse effect,
which produced the conditions we see on Venus today, is that
the evaporation of water vapor caused the temperature to rise so
high that the atmosphere became unbound.

This is not an explanation I've ever heard of.

1. The explanation I've heard involves 90 bars of carbon dioxide. Is
there any water vapor at all in the Venusian atmosphere?

Yes, about 0.005 AM (air masses) at present (which is nearly the
same as in our atmosphere).
But the D/H ratio tells us that there was once much more, perhaps
nearly the same as Earth (650 AM, 3/4 in the oceans).
It is thought that the water loss to space currently is nearly
balanced
by outgassing, and therefore the concentration will fall only slowly.

2. For an atmosphere that is alleged to be "unbound," there seems to
be quite a lot of it.

The theory says that most of the atmosphere escaped hydrodynamically
during the 'run-away' phase. It is now quite bound. In any case, the
CO2
observed today in the atmosphere I believe mostly outgassed after the
loss of the oceans.

I have seen a journal article that says the temperature would reach
'several thousand degrees' until the surface could 'radiate in the
visible'.

Reference?

I can't find it now.

The highest possible temperature is the effective
temperature of the Sun divided by the square root of 2. This is just
conservation of energy for an imaginary atmosphere that is completely
transparent to visible light and completely opaque at longer
wavelengths.

I don't know how you did this calculation, but it can't be right. The
temperature
also depends on the distance from the Sun. I get, with the Wien's law
approximation,

log (Ts/T) + E (1/T - 1/Ts) = log 4 + 2 log (R/Rs)

Let's compute the temperature if the Earth were replaced with such a
body.
Since Ts ~ 0.5 ev and R/Rs ~ 210, we'll assume E = 1.75 ev (the cutoff
of
'the visible'),

log (0.5/T) + 1.75 (1/T - 2) ~ 12

I estimate from that T ~ 0.125 ev or 1,450 K.

Of course no real atmosphere will be ideal in this fashion.

No, of course not. What would the Earth's surface temperature be if
the oceans evaporated entirely into the air? There's about
500 atm of water in the ocean, which is above the critical point. A
saturated H2O atmosphere will follow the vapor-pressure curve up
to the critical point, then the adiabatic rate from there - but that's
pretty shallow, since Cp 10 for a large region near critical.

The critical point is 218 atm and 647 K, and assuming Cp 10
above that, the surface temperature can't be more than

T = 647 K (500/218)^(1/10) = 703 K .

That's slightly cooler than Venus today, and is the maximum
temperature we could expect in a greenhouse on Earth.

Andrew Usher

On Jun 24, 10:49*am, Yousuf Khan wrote:
Robert J. Kolker wrote:
Yousuf Khan wrote:

And according to the Gaia Hypothesis, life on Earth itself will evolve
to absorb and subsume any climate conditions that will lead to runaway
greenhouse effects.

The planet is not a living organism. Organism live on the planet.

Okay, and so what's this got to do with whether or not "life on Earth"
will evolve to rectify the climate?

* * * * Yousuf Khan

well, it's always an error to think that evolution is purpose driven.
mutations are random, and wherever there's a niche, presumably one of
those random mutations will be such that it can exploit that niche.
that's one trouble with "intelligent design" theories; intelligence is
limited, compared to randomness.

z wrote:
Okay, and so what's this got to do with whether or not "life on Earth"
will evolve to rectify the climate?

Yousuf Khan

well, it's always an error to think that evolution is purpose driven.
mutations are random, and wherever there's a niche, presumably one of
those random mutations will be such that it can exploit that niche.
that's one trouble with "intelligent design" theories; intelligence is
limited, compared to randomness.

"Intelligent Design" is another word for Creationism, isn't it? They
don't believe in any kind of evolution. Everything on Earth was put
there fully formed by one major intelligence up in the sky or something?

Hasn't got anything to do with organisms evolving to rectify the
climate. One of the misconceptions of evolution is that something has to
evolve after a change in the climate or whatever. But in actual fact
what's really happening is that these organisms have already existed
prior to the change, and the change makes them far more successful than
they were before. So if the environment changes, the organisms that will
re-regulate the environment will already exist, and now will simply be
more successful.

Yousuf Khan

"Yousuf Khan" wrote in message
...
|z wrote:
| Okay, and so what's this got to do with whether or not "life on Earth"
| will evolve to rectify the climate?
|
| Yousuf Khan
|
| well, it's always an error to think that evolution is purpose driven.
| mutations are random, and wherever there's a niche, presumably one of
| those random mutations will be such that it can exploit that niche.
| that's one trouble with "intelligent design" theories; intelligence is
| limited, compared to randomness.
|
| "Intelligent Design" is another word for Creationism, isn't it?

"Design" implies planning. Only idiots attach "intelligent" to it,
if a god created us it is a pretty dumb god to run a toxic waste pipe
through a recreational area.

| They
| don't believe in any kind of evolution. Everything on Earth was put
| there fully formed by one major intelligence up in the sky or something?
|

That's the general idea.

| Hasn't got anything to do with organisms evolving to rectify the
| climate. One of the misconceptions of evolution is that something has to
| evolve after a change in the climate or whatever. But in actual fact
| what's really happening is that these organisms have already existed
| prior to the change, and the change makes them far more successful than
| they were before. So if the environment changes, the organisms that will
| re-regulate the environment will already exist, and now will simply be
| more successful.
|
| Yousuf Khan

Actually you've given an optimistic bias to the situation. All species
survive until killed, success has nothing to do with it.
It is not survival of the fittest but destruction of the weakest that
drives evolution. That's also called "luck".

Dirk Bruere at NeoPax wrote:
Fred Kasner wrote:
Yousuf Khan wrote:
Andrew Usher wrote:
This wasn't supposed to go to soc.men actually.

My point (I didn't quite finish) was that there can be no such
thing as a true 'run-away greenhouse', that there can be no
abrupt tipping point but only a gradual change. It is
nonetheless irreversible, though.

Also, this has no effect on projections of man-made global
warming, as it can't occur unless solar input is considerably
higher than today.

Andrew Usher

And according to the Gaia Hypothesis, life on Earth itself will
evolve to absorb and subsume any climate conditions that will lead to
runaway greenhouse effects.

Yousuf Khan

It would have to have life develop into a very different set of
species than we now have. Most or intolerant of high temperatures as
this tends to cause proteins to degenerate. And protein specificity
and moderate temperatures allows this. With very high temperatures
there might continue to be unicellular life forms that can tolerate
such but not multicellular and highly specialized life forms. Besides
such radical evolutionary changes would take tens if not hundreds of
millions of years. By then higher life forms might very well have
succumbed to more quickly destructive catastrophes.
FK

Look, we're only talking about an average temp increase of 10 degC.
There's more than that between equatorial and mid lattitudes.


What about the non-poikiothermic life forms. They would find their
chemical reaction rates approximately doubled with such an increase in
temperature.
FK

Fred Kasner wrote:
Dirk Bruere at NeoPax wrote:
Fred Kasner wrote:
Yousuf Khan wrote:
Andrew Usher wrote:
This wasn't supposed to go to soc.men actually.

My point (I didn't quite finish) was that there can be no such
thing as a true 'run-away greenhouse', that there can be no
abrupt tipping point but only a gradual change. It is
nonetheless irreversible, though.

Also, this has no effect on projections of man-made global
warming, as it can't occur unless solar input is considerably
higher than today.

Andrew Usher

And according to the Gaia Hypothesis, life on Earth itself will
evolve to absorb and subsume any climate conditions that will lead
to runaway greenhouse effects.

Yousuf Khan

It would have to have life develop into a very different set of
species than we now have. Most or intolerant of high temperatures as
this tends to cause proteins to degenerate. And protein specificity
and moderate temperatures allows this. With very high temperatures
there might continue to be unicellular life forms that can tolerate
such but not multicellular and highly specialized life forms. Besides
such radical evolutionary changes would take tens if not hundreds of
millions of years. By then higher life forms might very well have
succumbed to more quickly destructive catastrophes.
FK

Look, we're only talking about an average temp increase of 10 degC.
There's more than that between equatorial and mid lattitudes.


What about the non-poikiothermic life forms. They would find their
chemical reaction rates approximately doubled with such an increase in
temperature.
FK

Emigrate.

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
Remote Viewing classes in London

Androcles wrote:
"Yousuf Khan" wrote in message
...
| Hasn't got anything to do with organisms evolving to rectify the
| climate. One of the misconceptions of evolution is that something has to
| evolve after a change in the climate or whatever. But in actual fact
| what's really happening is that these organisms have already existed
| prior to the change, and the change makes them far more successful than
| they were before. So if the environment changes, the organisms that will
| re-regulate the environment will already exist, and now will simply be
| more successful.
|
| Yousuf Khan

Actually you've given an optimistic bias to the situation. All species
survive until killed, success has nothing to do with it.
It is not survival of the fittest but destruction of the weakest that
drives evolution. That's also called "luck".

Whatever, works out to the same effect.

Yousuf Khan

"Yousuf Khan" wrote in message
...
| Androcles wrote:
| "Yousuf Khan" wrote in message
| ...
| | Hasn't got anything to do with organisms evolving to rectify the
| | climate. One of the misconceptions of evolution is that something has
to
| | evolve after a change in the climate or whatever. But in actual fact
| | what's really happening is that these organisms have already existed
| | prior to the change, and the change makes them far more successful
than
| | they were before. So if the environment changes, the organisms that
will
| | re-regulate the environment will already exist, and now will simply be
| | more successful.
| |
| | Yousuf Khan
|
| Actually you've given an optimistic bias to the situation. All species
| survive until killed, success has nothing to do with it.
| It is not survival of the fittest but destruction of the weakest that
| drives evolution. That's also called "luck".
|
| Whatever, works out to the same effect.
|
| Yousuf Khan

This is not so. "Survival of the fittest" evolution means that
individuals within the species compete with each other - for
example the antelope chased by a lion escapes and passes on
it genes at the expense of the slower antelope that is caught.
That didn't help the dodo, they were all wiped out by man.
The effects are very different, on the optimistic side the
species improves itself gradually, on the pessimistic side
the species becomes extinct. An extinct species cannot
have one individual more fit than another when neither exist.