Re: [asa] Global Warming

From: j burg <hossradbourne@gmail.com>
Date: Tue Jul 29 2008 - 19:26:21 EDT

Thanks for additional illumination.

Burgy

On 7/29/08, Rich Blinne <rich.blinne@gmail.com> wrote:
> On Tue, Jul 29, 2008 at 9:35 AM, j burg <hossradbourne@gmail.com> wrote:
>
>>
>> While I pretty much accept the IPCC findings and analysis, I am still
>> a bit skeptical of the overall issue. Two reasons: (1) the amount of
>> sunlight reaching the earth is, indeed, dependent on CO2 levels. But
>> it is much more dependent on water vapor (cloud) levels.
>
>
> The effects of clouds have been factored into the GCMs. See here:
> http://www.iop.org/EJ/article/1748-9326/3/1/014001/erl8_1_014001.html
>
> Also, satellite technology for measuring the effects of different types of
> clouds is getting much better:
>
> http://www.opticsinfobase.org/abstract.cfm?URI=oe-16-6-3931
>
>
>
>>
>> (2) Soot levels also may play a part. If so, this could be an argument
>> either way.
>>
>>
> Soot does not equal aerosols, BTW. As a first-level explanation it holds but
> rather it is the anthropogenic SO2 is what is the primary concern. Last year
> there was a PNAS paper of how both the natural variability -- specifically
> solar irradiation variability -- and anthropogenic variability played
> together.
>
> http://www.pnas.org/content/104/10/3713.full
>
> What they did was to use cosmogenic Be-10 in ice cores as a proxy for solar
> irradiation levels. The problem with Be-10 is how much to scale it so they
> used three different scaling factors to see which fit the paleoclimatic
> record the best. Beryllium 10 is like Carbon 14 in that solar irradiation
> causes that isotope to be produced.
>
> The forcings used in the model are shown here
> http://www.pnas.org/content/104/10/3713/F1.large.jpg
>
> The blue line is large scaling, the red medium, and the green small.
>
> The results of plugging in the model is shown here:
> http://www.pnas.org/content/104/10/3713/F3.large.jpg
>
> Graph a is the current paleoclimatic reconstructions of the temperature
> record which becomes the gray background in graph b. Graph b shows the
> medium scaling of Be-10 is the best fit. What this shows is we have a good
> grasp on what is causing the variability in the pre-industrial period
> although one interesting finding of the paper is that even here solar
> variability was less of a factor than volcanic eruptions. Graph c is during
> the instrumental period. Note how if you don't include CO2 forcing and even
> with large scaling you are 0.5 degrees C off. Yet again for the upteenth
> billionth time, antropogenic climate change is shown even when both aerosols
> and solar irradience differences are taken into account.
>
> Rich Blinne
> Member ASA
>

-- 
Burgy
www.burgy.50megs.com
To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Tue Jul 29 19:26:52 2008

This archive was generated by hypermail 2.1.8 : Tue Jul 29 2008 - 19:26:52 EDT