> > >. Any sensible understanding of the carbon cycle supports
> > > > > the intuitively obvious conclusion: the sooner, the better.
> > > > You're wrong here, there's a carbon saturation after which it
> > > > ceases to be a forcing.
> > > This isn't really true, it turns out. Consider Venus.
> > Consider Mars which has an atmosphere of 230000 ppm co2 why then
> > is it not an oven?
> Do you understand the concept of optical depth? Please be serious.
Yes, and that's exactly why there's a saturation of a given gas.
Also it's important to note that practice frequently deviates from
theory.
http://www.scotese.com/climate.htm
This shows clearly a geological history of global temperature.
Note the plateau at 22 degrees C. These times included ANY time when
the atmospheric CO2 exceeded approximately 600 ppm, including millions
of years when it ixceeded 2000 ppm and further milions of years when it
exceeded 4000 ppm with no additional corresponding warming whatsoever.
What source to you use to imply that that is either innacurate or
irrelovent? If we are planning to expend the herculean efforts
involved in a 550 ppm stabilization (again, I am sceptical that 25%
current emissions would produce that) and 600 ppm is the response
ceiling, then what's the point??
This source is a little unreliable due to an obvious bias, but the
graph of co2 vs temp halfway down is useful and fact checks.
http://www.clearlight.com/~mhieb/WVFossils/Carboniferous_climate.html
Again, I don't endorse anything on this page except that graph.
> Simply because there are a great deal of factors at
> > work other than carbon. Venus isn't a fair comparison due to several
> > factors, among them, 1) it is closer to the sun.
> Not close enough. Do you understand the relationship between the
> Stefan-Boltzmann law and planetary surface temperature? Again this is
> first-year stuff.
Close enough to have 1.89 times the insolation per square meter
(insolation is an inverse square function). That's enough to increase
the temperature from our historical average of 22 degrees C to 73
degrees C other things being equal. now granted that venus' surface
temp is 400 degrees C, mainly attributed to greenhouse effects,
however, the optical depth is vastly greater than our own.
Yes, I understand the concepts involved in blackbody radiation,
and in radiative forcing. It is nonetheless a fact that once the
atmosphere is completely opaque at the indicated range of wavelengths,
adding more opacifier doesn't result in additional warming.
Look, I am an engineer, not a scientist. One thing that means in
practice is that I give far more credence to a real world in-situ study
than I do to a theory. and while in theory, it is possible to have a
runaway greenhouse effect that warms this planet to venerian
temperatures, the geological history of the planet indicates in pink
neon that this simply isn't possible. Regardless of the co2
concentration.
> Us old guys are partial to Wallace and Hobbs, "Atmospheric Science, an
> Introductory Survey" 1977 but there are plenty of alternatives. I understand
> that there is a new edition of W&H as of 2006.
> 2) Our moon has
> > been shown to have gravitationally "skimmed" our atmosphere such that
> > there is a very great deal less total volatile volume to work with on
> > earth.
> News to me. Are you making that up? What does that have to do with anything
> if so? And what do you mean by "volatile"?
No. gasses leak from the atmosphere when the average temperature
velocity is greater tthan 1/10 of escape velocity. For the earth, the
moon produces a very significant reduction (circa 15%) in that escape
velocity which in turn increases the amount of atmospheric leakage.
Particularly true for the primordial atmosphere which was considerably
hotter and thicker than the current one, and when the moon was a good
deal closer to the earth. To be honest, I couldn't find a cite.
If you look at venus as compared to earth, you will find that a)
venus has more co2 in it's atmosphere than there is carbon on the
planet earth. B) the venerian atmosphere is several times as thick as
our own, despite being of the same planetary mass. Please explain
these differences.
I read about this in a scholarly paper 6 years ago, but if you
choose to deny it because I can't find it, we can drop the point and
continue to disagree on this point due to the fact that I can't locate
my source.
However, that doesn't change the fact that the temperature
response due to added co2 to the atmosphere is 22 degrees C. for
whatever reason that is the case, it quite clearly is. Additionally,
it quite clearly is the case that that co2 concentration is right near
the 600 ppm mark, close enough to your 550 target stabilization mark to
make no difference.
> > Okay, adult, present the alternate source of energy you are
> > supporting. Or present some evidence that 25% of current emissions
> > would produce a stable carbon cycle.
> Let's try to take our time here. I will just answer this one question, and
> then we can see how it impacts the rest of your opinions.
>
> I refer you to IPCC WG1 TAR 3, section 2.3.2.2; you can find it at
> http://www.grida.no/climate/ipcc_tar/wg3/075.htm .
The TAR generally bothers me as a source. It tends toward
political motivation and for the most part presents as a collection of
statements without the bulk of the evidence to support them. However,
accepting it as a valid source, I still don't see a stabilization
mechanism defined in your reference, merely a comparison of different
"stabilization scenarios", and a bald assertion that these are indeed
stabilization scenarios. What mechanism produces the carbon
sequestration that you and they assert will remove the annually added
co2 from the atmosphere? the global land use currently in play
prevents that mechanism from being the addition of more forest land,
and the ocean under warming conditions is a source of co2, not a sink.
Also worth considering here is that 25% of current emissions
equates to a per capita emission of 1 ton per year per person averaged
over the planet. That's a 33% reduction compared to Frances current
per capita emissions. France already gets all of it's grid power from
carbon neutral sources, uses public transport extensively, and drives
efficient cars small distances, as well as having a generally apartment
living social structure.
I should also mention here that only half the increased co2 comes
from burning fossil fuels. the other half is from land use changes,
concrete production, and other lower order sources. so even if we were
to totally cease using fossil fuels as a source of energy, we would
still exceed your target by 100%. I don't see any way to accomplish
even that, let alone the rest of it.
It really is a little unreasonable to discuss WHAT You propose to
do and WHY you propose doing it without at least a little consideration
to HOW it will be accomplished, and at what cost. That's why my
previous posts included references to this, which you so casually
snipped.
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