Re: Ping Bil Slowman; The global warming hoax reveiled

On Nov 28, 10:36 pm, Bill Sloman <bill.slo...@xxxxxxxx> wrote:
On Nov 28, 5:15 pm, dagmargoodb...@xxxxxxxxx wrote:

On Nov 27, 10:19 pm,Bill Sloman<bill.slo...@xxxxxxxx> wrote:

On Nov 26, 9:18 pm, dagmargoodb...@xxxxxxxxx wrote:
Or just do an error-budget analysis.  The AGW contribution alleged
from CO2 is, well, not even clear.  A range of estimates from ~0.25 to
1 W/m^2 out of roughly 300W/m^2 has been offered.  (That wide an
uncertainty band is pretty pathetic on its face, isn't it?)

Check out the ranges of forcings estimated here:
 http://en.wikipedia.org/wiki/Greenhouse_gas

"   * water vapor, which contributes 36–72%     [a 2:1 range]
    * carbon dioxide, which contributes 9–26%  [3:1]
    * methane, which contributes 4–9%
    * ozone, which contributes 3–7%"

These aren't, stictly speaking. forcings.

If you had read further down the page, you would have come across this
line

"It is not possible to state that a certain gas causes an exact
percentage of the greenhouse effect. This is because some of the gases
absorb and emit radiation at the same frequencies as others, so that
the total greenhouse effect is not simply the sum of the influence of
each gas. The higher ends of the ranges quoted are for each gas alone;
the lower ends account for overlaps with the other gases.[8][9]"

Forcings are calculated for  for actual atmospheres containing
specific concentrations of gases and this particular source of
uncertainty largely goes away. Since the lapse rate means that water
vapour concentrations drop away quite rapidly with increasing
altitude, this isn't an entirely trivial calculation.

For the record, you have just proved - once again - that you don't
know what you are talking about.

You skipped the introductory sentence:
"When these gases are ranked by their contribution to the greenhouse
effect, the most important are:"

So, you've made a useless distinction. In IPCC-ian cant, "forcing"
means yet something else to what it meant in common language.

The upshot is still that--whatever the term-of-art be in your
particular cult--the heat inputs from those sources are not accurately
quantified, and their uncertainty dwarfs the heating thought to be
from manmade CO2.



It might be if it had been offered by someone who knew what they were
talking about. These are the sorts of numbers that Christopher
Monckton comes up with

http://www.altenergyaction.org/Monckton.html#sec7

More reliable sources seem to be able to come up with a narrower
range.

http://atoc.colorado.edu/~seand/headinacloud/?p=204

They estimate it using models:

  "So how is Radiative Forcing calculated? For the most
    part, it is estimated using data from what is referred
    to as General Circulation Models (GCM’s). These
    models use numerous methodologies[...]"

As I mentioned in the post to which you are responding, (a point also
made in the wikipedia page you cited, but don't seem to have read
either), the greenhouse effect of each gas in the atmosphere depends
on the concentration of the other greenhouse gases in the atmosphere,
and you have to construct a model of the atmosphere before you can
calculate a radiative forcing for that atmosphere.

I read it, but I don't get your point. The alleged contribution of
these GHGs to Earth-warming in Earth-atmosphere is what matters,
nothing else.

It's not a mystery, it's a planet, with a well-known atmospheric
composition. So the correct measure of GHG-warming potential would be
of each gas' contribution in the mix as naturally occurs on Earth, or
dF/dConcentration in close approximations of that mix, or some such,
obviously.

If they don't know that exactly, they don't know anything.

If you want to insist the mix varies widely, having large effects,
then you have to show that your model accurately predicts how much
water vapor and so forth appears everywhere on the planet, at all
levels of the atmosphere, and integrates that correctly over time.

You can't meet that burden.

And still you should be able to supply one overall measure of each
gas' influence, to a precision better than the AGW you're asserting
for CO2. Just integrate the contribution, per volume, over the
atmosphere.

That gives a number, per gas, that could be listed in that table.
And, to be of any use, it'd better be an accurate number.



gives a figure of 1.66 W/m², with a range between 1.49 and 1.83 W/m².

The same source goes on to give a 4:1 uncertainty range(!) for net
anthropogenic forcing:

  "Overall, the total net anthropogenic Radiative Forcing
   is equal to an average value of 1.6 W/m² [0.6 to 2.4 W/m²].
   This means a warming of the climate."

IIRR these are 95% confdence limits, and include quite a lot of
uncertainty to cover features of the atmosphere that the current
generation of climate models, running on the current generation of
computers don't model well.

We may be able to do better  in a few years

Despite your protestations: 4:1 bounds on a 95% confidence interval.
That's a joke, of course.


--
Cheers,
James Arthur
.

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