[ RadSafe ] RE: extremism

Fri Mar 23 09:03:41 CDT 2007

Steven,

This is from Wikipedia: http://en.wikipedia.org/wiki/Greenhouse_gas

Water vapor is a naturally occurring greenhouse gas and accounts for the 
largest percentage of the greenhouse effect. Water vapor concentrations 
fluctuate regionally, but human activity does not directly affect water 
vapor concentrations except at very local scales.

In <http://en.wikipedia.org/wiki//wiki/Climate_model>climate models an 
increase in atmospheric temperature caused by the greenhouse effect due to 
anthropogenic gases will in turn lead to an increase in the water vapor 
content of the troposphere, with approximately constant 
<http://en.wikipedia.org/wiki//wiki/Relative_humidity>relative humidity. 
The increased water vapor in turn leads to an increase in the greenhouse 
effect and thus a further increase in temperature; the increase in 
temperature leads to still further increase in atmospheric water vapor; and 
the feedback cycle continues until equilibrium is reached. Thus water vapor 
acts as a positive feedback to the forcing provided by human-released 
greenhouse gases such as CO2<http://en.wikipedia.org/wiki/#_note-7>[9] (but 
has never, so far, acted on Earth as part of a runaway feedback). Changes 
in water vapor may also have indirect effects via cloud formation.

<http://en.wikipedia.org/wiki//wiki/Intergovernmental_Panel_on_Climate_Change>Intergovernmental 
Panel on Climate Change (IPCC) 
<http://en.wikipedia.org/wiki//wiki/IPCC_Third_Assessment_Report>IPCC Third 
Assessment Report chapter lead author 
<http://en.wikipedia.org/wiki//wiki/Michael_Mann_%28scientist%29>Michael 
Mann considers citing "the role of water vapor as a greenhouse gas" to be 
"extremely misleading" as water vapor can not be controlled by 
humans.<http://en.wikipedia.org/wiki/#_note-8>[10]<http://en.wikipedia.org/wiki/#_note-9>[11]<http://en.wikipedia.org/wiki/#_note-10>[12] 
The IPCC report has discussed water vapor feedback in more 
detail.<http://en.wikipedia.org/wiki/#_note-11>[13]

Bob

At 09:26 PM 3/22/2007, Steven Dapra wrote:
>March 22
>
>         My thanks to Bob Casparius for posting this very clear NCDC 
> explanation of the role of water vapor, accompanied by the explanation of 
> what we *do not* know.
>
>         So there is no confusion or uncertainty on anyone's part, that 
> link I offered was not to my site, nor do I necessarily accept everything 
> that was said on the site. (See the end of Bob's posting.)       I do not 
> know if the site was promoting coal or not and can't comment on 
> that.  Bob suggested that the site might be biased in its discussion of 
> global warming and his suggestion may well be true, I don't know.  It 
> cannot be said often enough that *everyone* has a bias, and we might do 
> well to keep that in mind.  With respect to strip mining, it may not be a 
> pretty sight, however it has nothing to do with global warming.  The 
> UMTRA project left us with some rather large tailings piles.  I know some 
> of that is from bomb production, however some of it is from reactor fuel 
> too -- at least I assume it is.  I could stand to be corrected on that point.
>
>Steven Dapra
>sjd at swcp.com
>
>
>
>At 02:57 PM 3/22/07 -0400, Bob Casparius wrote:
>>The National Climate Data Center [NCDC] even says that any increase in 
>>water vapor in the atmosphere is due to increases in atmospheric 
>>temperature. Therefore, the increased atmospheric temperature must be due 
>>to something other than increased water vapor. And if there is increased 
>>water vapor in the atmosphere it is due to increased atmospheric temp.
>>
>>The following is from http://lwf.ncdc.noaa.gov/oa/climate/gases.html
>>
>>"Water Vapor is the most abundant greenhouse gas in the atmosphere, which 
>>is why it is addressed here first. However, changes in its concentration 
>>is also considered to be a result of climate feedbacks related to the 
>>warming of the atmosphere rather than a direct result of 
>>industrialization. The feedback loop in which water is involved is 
>>critically important to projecting future climate change, but as yet is 
>>still fairly poorly measured and understood.
>>
>>As the temperature of the atmosphere rises, more water is evaporated from 
>>ground storage (rivers, oceans, reservoirs, soil). Because the air is 
>>warmer, the relative humidity can be higher (in essence, the air is able 
>>to 'hold' more water when its warmer), leading to more water vapor in the 
>>atmosphere. As a greenhouse gas, the higher concentration of water vapor 
>>is then able to absorb more thermal IR energy radiated from the Earth, 
>>thus further warming the atmosphere. The warmer atmosphere can then hold 
>>more water vapor and so on and so on. This is referred to as a 'positive 
>>feedback loop'. However, huge scientific uncertainty exists in defining 
>>the extent and importance of this feedback loop. As water vapor increases 
>>in the atmosphere, more of it will eventually also condense into clouds, 
>>which are more able to reflect incoming solar radiation (thus allowing 
>>less energy to reach the Earth's surface and heat it up). The future 
>>monitoring of atmospheric processes involving water vapor will be 
>>critical to fully understand the feedbacks in the climate system leading 
>>to global climate change. As yet, though the basics of the hydrological 
>>cycle are fairly well understood, we have very little comprehension of 
>>the complexity of the feedback loops. Also, while we have good 
>>atmospheric measurements of other key greenhouse gases such as carbon 
>>dioxide and methane, we have poor measurements of global water vapor, so 
>>it is not certain by how much atmospheric concentrations have risen in 
>>recent decades or centuries, though satellite measurements, combined with 
>>balloon data and some in-situ ground measurements indicate generally 
>>positive trends in global water vapor."
>>
>>The website: http://www.clearlight.com/~mhieb/WVFossils/ice_ages.html
>>
>>That Steven Dapra sites appears to be promoting coal as an energy source, 
>>which is another source of CO2 when burned. This makes you wonder if they 
>>are not bias in their presentation of global warming. Check out the 
>>discussion of strip mining:
>>
>>http://www.geocraft.com/WVFossils/StripMiner.html
>>
>>Bob
>
>[edit]
>
>
>
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Robert Casparius
Radiation Safety Officer
AECOM
Department of Environmental Health & Safety
x2243

http://www.aecom.yu.edu/ehs/Secondary%20Sites/AE_Radiation.htm