"Joe S." <anon@mous.com> wrote in message
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"Stan de SD" <standesd_DIGA_NO_A_SPAM@covad.net> wrote in message
news:15f38$43b9c0d6$45035f0b$24902@msgid.meganewsservers.com...
"Matt" <matttelles@sprynet.com> wrote in message
news:1136244503.761557.21930@g49g2000cwa.googlegroups.com...
Stan de SD wrote:
"john fernbach" <fernbach1948@yahoo.com> wrote in message
news:1136239587.768538.301620@z14g2000cwz.googlegroups.com...
If our society's CO2 emissions cause a minor warming of the world's
climate and a few changes in weather patterns around the world,
it's
no
big deal, right?
Wrong.
Consider what warmer and dryer weather than normal is currently
meaning
for Oklahoma City, according to this story from the World News
(Australia),
Note the paragraph buried deep in the story about "there's no rain
in
the forecast"
for the fire-ravaged Southwest.
Show us the mechanism where increased CO2 in the atmosphere causes
the
earth
to warm up, and explain how it can create such an effect in light of
the
fact that the most prevalent "greenhouse" gas in our atmosphere is
water
vapor (H2O). If necessary, simplify the problem by treating both the
sun
and
the earth as radiating black bodies with Boltzmann distributions and
mean
temperatures of 5500K and 300K respectively. Provide a rough idea of
the
amount of energy (to the nearest %) that is (a) reflected, (b)
absorbed,
and
(c) transmitted through (1) saturated water vapor @ 300K, (2) CO2 @
200
ppm,
and (3) CO2 @ 400 ppm.
Um... ok. Will this really help you a lot?
Starting with a heat balance will provide an indication of how much of
an
issue this is...
CO2 absorbs infrared radiation and retains it as heat. In addition, CO2
is fairly small
as a percentage of the atmosphere, so increasing it means a large
differential in the
atmospheric makeup.
The main issues are how much of each component are there, what the heat
capacities are, what the transmission and abosrption are per
concentration
unit at given temperatures AND wavelengths.
I have no idea why I would wish to treat the earth and sun as radiating
black bodies,
since they have nothing in common.
Because it allows allows us to develop a THERMAL MODEL (AKA "heat
balance")
using known formulae - a simple model to use as bounds for doing a basic
"sanity check"...
The sun is effectively all gas,
whereas the earth
is a solid core with a gaseous atmosphere.
You seem to be missing the point as to why I refer to "black-body
radiation". We don't need to know what happens at the core for the sake
of
this model - what we care about is the heat at the surface, and the
blackbody model explains it quite well. If you want to add some
emissivity
factors to correct for the surface characteristics, fine with me, but
that
still doesn't change the basic applicability of the model.
As far as the rest of it goes, I couldn't tell you the numbers without
looking them up.
But I assume you are trying to get at the fact that the earth's climate
has been
established to be the differential between reflected and radiated
energy.
Try a differential betweem absorbed and radiated energy.
There was a
big study on this some years back. Sorry, I really can't remember the
fellow's name,
but it was rather interesting.
From what I remember, the earth reflects back something like a third
of
the energy
radiated onto it by the sun. Good enough?
Not quite, but a better try than 98% of the typical Usenet respondents.
Matt
(a mathematician with an engineering degree).
Stan
( Chem E)
Well, Mr. Chem E, excuse me but you must understand that most of us are
not
especially impressed by folks who feel compelled to add their credentials
after their name -- is that supposed to prove something?
I only responded to the other poster, Mister Mathematician, who felt the
need to share his credentials with is. You feeling inadequate or what?
Actually, what I am impressed by is the fact that you ignore the
conclusions
reached by all but the most fringe elements of the worldwide scientific
community.
Thanks for sharing your complete ignorance on the subject matter with us.
Obviously you need to lash out because you have no clue as to how to
approach the subject.
.
