In article ,
Phil Hays wrote:

Steve Schulin wrote:
Phil Hays wrote:
Steve Schulin wrote:

Even a small
change in that expected value could have a big effect on narrowing down
the uncertainty in atmospheric lifetime value assigned to CO2. The
alarmists typically refer to a century or more. I've seen the data fit
to a 67-year value. IPCC presents an even wider possible range.

Bogus assumption/no sign of learning. There is no single lifetime of
CO2 in the atmosphere, as the IPCC points out. ...

Well, if you can imagine a global mean temperature, surely you can
understand the difference between atmospheric lifetime value closer to
50 years than to 200 years (as presented in he SAR), or between
atmospheric lifetime value closer to 5 years than to 200 years. (as
presented in the TAR).

... There are many
processes that remove CO2 from the air, into many different carbon
stores, and most of these processes are reversable.

Very true.

Good start. Then let me if you can continue. To talk about CO2 as
having a single "lifetime" is too simple of a model. This is why:

The exchange of carbon as CO2 with the mixed layer of the oceans has a
very short time scale, on the order of years. This process is
reversible by just reducing the CO2 level in the atmosphere.

The sequestration of carbon in silicate rock weathering has a longer
time scale, on the order of 100,000 years. This process is not
directly reversible, but is reversed by plate tectonics.

If we tried to measure the "lifetime" of CO2 over a few years, we
would see mostly the results of the first process. We would measure a
"lifetime" less than a decade.

If we tried to measure the "lifetime" of CO2 over a million years, we
would see mostly the results of the second process. We would measure
a "lifetime" on the order of 100,000 years.

With just these two processes, there would no single lifetime for CO2.
The "lifetime" we would measure would depend on how long of time
period we looked at. Of course, reality is more complex than this.
But that doesn't change the conclusion. There is no single lifetime
for CO2.

Gee whiz, Phil. I have repeatedly specified the timeframe I'm
discussing. It is the timeframe relevant to such questions as whether
anthropogenic emissions will result in doubled atmospheric
concentrations of CO2 in policy-relevant period.

Very truly,

Steve Schulin
http://www.nuclear.com