Re: [asa] climate change severity

Some clarity:
 
Cows do not contribute CO2 to the Earth's atmosphere. However, they do contribute a large amount of methane (CH4). Methane is also a greenhouse gas, and in fact is a much more effective one than CO2. This means, of course, that a smaller amount of methane can be more problematic than a given amount of CO2. So a few cows can contribute more greenhouse material to the atmosphere than a few cars.
 
The conclusion here, however, should not be that since cows are more problematic than cars, that means that cars aren't a problem. That conclusion indicates that the complexity of the problem is not really understood by the person conluding it. The reason cows are a problem is not because of cows, it is because of humans, who raise them for milk and beef. Humans, in the last 100 years, have gone from ~2 billion in population to now over 6.5 billion, and 7 billion is only a few years away. The global population of cows, as I stated in a previous post, has risen exponentially over the past 100 years, just like human population has done, and it is a direct result of human population growth. Cows have gone from about 0.5 billion in ~1900 up to now between 2.5-3 billion. The methane contribution of cows, therefore, must be viewed as an anthropogenic source, not a natural one. Cows would not exist anywhere close to the populations they do today if humans did not raise them for food. Rather than indicating that cars are not a problem, this indicates that both cars AND cows are a problem, and they are both due to human activity. Human activities have wide and far-reaching consequences.
 
These data are much more convincing when they can be viewed visually. I have placed a portion of one of my lectures online at: http://web.olivet.edu/~ccarriga/GEOL340_30.ppt
I will not leave it up for more than a couple of days. It should be stated that the figures in this file are subject to copyright laws - their use here is for educational purposes only. It is a large file ~27 MB so you'll need a fast connection to view it. Please do not save the file or copy it in any way unless you contact me first for permission.
 
I highly recommend this very balanced and well-reasoned textbook for a complete look at issues of climate change:
W.F. Ruddiman, 2001, Earth's Climate: Past and Future, WH Freeman & Co., ISBN 0716737418
 
It should be noted that I have not here attempted to state what policies should be implemented by people or states. That, in my opinion, is a different question with additional complexities. The first step is to recognize the geochemical facts for what they are.
 
Best,
Charles
 
_______________________________
Charles W. Carrigan, Ph.D.
Assistant Professor of Geology
Olivet Nazarene Univ., Dept. of Physical Sciences
One University Ave.
Bourbonnais, IL 60914
PH: (815) 939-5346
FX: (815) 939-5071
ccarriga@olivet.edu
http://geology.olivet.edu/
 
"To a naturalist nothing is indifferent;
the humble moss that creeps upon the stone
is equally interesting as the lofty pine which so beautifully adorns the valley or the mountain:
but to a naturalist who is reading in the face of the rocks the annals of a former world,
the mossy covering which obstructs his view,
and renders indistinguishable the different species of stone,
is no less than a serious subject of regret."
          - James Hutton
_______________________________

>>> PvM <pvm.pandas@gmail.com> 1/5/2007 12:02 AM >>>

Seems Janice is once again trivializing the science behind the human
component to CO2. Perhaps cows are more damaging than cars when it
comes to CO2, but cars make up a small amount of human CO2 emissions.

We all at risk to ridicule that which we don't understand...

Will she ever learn from Augustine?...

On 1/4/07, Janice Matchett <janmatch@earthlink.net> wrote:
>
> At 12:42 PM 1/4/2007, Charles Carrigan wrote:
>
> Don,
>
> Human beings began pumping CO2 into the atmosphere well before 1930. I
> understand wanting to be skeptical of bandwagons, but the data that indicate
> human impact are pretty strong. Natural warming may also be occurring, but
> the data clearly show a massive anthropogenic involvement.
>
> Ice core measurements indicate that in the year ~1800, the concentration of
> CO2 in the atmosphere was down near 275 ppm, but steadily rising over the
> next 100 years to reach ~300 ppm by 1900. Direct measurement of
> atomospheric CO2 goes back to the late 1950s, when the value was up to ~315
> ppm; today it is near ~375 ppm. Although we've certainly done much more in
> the past 50 years, humans did plenty between 1800 and 1930.
>
> To put it in natural context - in the deep geologic record, CO2 has
> fluctuated in the atmosphere between ~180-280 ppm over the last at least
> 400,000 years, and I believe the record now goes back even further to the
> past 650 ka; at no point in that history has CO2 reached the levels it is at
> today, or even the levels it was at in 1950. The concentration of CO2 in
> past atmospheres is measured by trapped gas bubbles in deep ice cores from
> Antarctica. There is a tremendous inverse correlation between times of low
> CO2 (~180 ppm) and large amounts of continental ice as interpreted by
> delta18O data (stable isotopes of H2O), and also the reverse - times of high
> CO2 (~280 ppm) correlate with times of low continental ice. This obviously
> fits with the notion that CO2 is a greenhouse gas.
>
> A couple of references:
> Petit, J.R., et al., 1999, Climate and Atmospheric History of the Past
> 420,000 Years from the Vostok Ice Core, Antarctica. Nature, 399, 429-436.
> Friedli et al., 1986, Ice Core Record of the 13C/12C Ratio of Atmospheric
> CO2 in the Past Two Centuries. Nature, 324, 237-238
>
> There is no question that human beings over the past 200 years have
> dramatically altered the concentration of CO2 in Earth's atmosphere. There
> is also a clear connection between CO2 concentration and global T.
>
> Best,
> Charles
>
> @ I see you didn't get the memo.
> http://cagle.msnbc.com/working/061213/lester.jpg
>
> ~ Janice
>
>
>

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Received on Fri Jan 5 12:46:42 2007