In message , Retief
writes
On Thu, 02 Nov 06 11:35:01 GMT, (Lloyd Parker)
wrote:

No, it says: "The current level or stock of greenhouse gases in the
atmosphere
is equivalent to around 430 parts per million (ppm) CO2, compared with only
280ppm before the Industrial Revolution. These concentrations have already
caused the world to warm by more than half a degree Celsius and will lead to
at least a further half degree warming over the next few decades, because of
the inertia in the climate system."

All the GH gases are equivalent to CO2 of 430 ppm.

This is simply not true:

http://www.profc.udec.cl/~gabriel/tu...cp1/1-11-2.gif

Clearly these different gases have different absorption spectra, and
can never be "equivalent to CO2"...

They can have a net thermal effect similar to CO2.


That is, the response of CO2 to a shifting spectrum is different than
the other gases.

What do you mean by a "shifting spectrum" ?


And NOAA notes that the solar emission spectrum has changed:
http://www1.ncdc.noaa.gov/pub/data/p...olar_variabili
ty/lean2000_irradiance.txt

"Estimated increases since 1675 are 0.7%, 0.2% and 0.07% in broad
ultraviolet, visible/near infrared and infrared spectral bands, with
a total irradiance increase of 0.2%."

So ?


BTW, from a historical standpoint, we are at a very low atmospheric
CO2 concentration...

http://en.wikipedia.org/wiki/Image:P...on_Dioxide.png

Not from a human civilization standpoint. What does it matter what happened
millions of years ago? Heck, why not go back to the big bang -- CO2 was zero
then!

Oh, you mean that the Earth supports no life, because a "climate
catastrophe" (as you predict impending) has exterminated all life,
when those past CO2 concentrations went up to an estimated 5-6000 ppm?

I's sure that if he'd intended to say something stupid and out of
context he could have managed it without your help !


Cheers, J/.
--
John Beardmore