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[Phys-L] Global Warming (Was: just for fun?)



Here is a paper which shows that CO2 rise precedes global warmng:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&ved=0
CGkQFjAH&url=http%3A%2F%2Fwww.seas.harvard.edu%2Fclimate%2Fseminars%2Fpdfs%2
FShakunetal2012.pdf&ei=AyTLUqGuF-mh2AX3h4D4BA&usg=AFQjCNFfCQt6R9A3GY1R0ch9TU
xgtYGMAw&sig2=ZEwncef5f68ruKsgZFRPZg&bvm=bv.58187178,d.b2I

But if you search on "Global warming preceded by increasing carbon dioxide"
you will hit it. It does not appear to be the recent ice core data that I
saw, but can not find the reference for. But I may eventually find it.

The negative feedback is certainly one of the important factors. So far
there is little evidence of significant cloud cover negative feedback. The
plant growth is probably not negative feedback because some studies have
shown that in reality the growth might be slower. This also poses serious
problems for food crops. In addition when the plant dies, the carbon is
released back into the atmosphere. The only way that plant growth can
permanently sequester the carbon is if it ends up in location where it can
not decay. This is the formation of coal and oil, which requires long
geological time. In either case faster growth is just a temporary
phenomenon, because eventually the plant dies. At present, the cloud cover
is virtually the only remaining problem with the human induced global
warming model. Most of the papers which claim that this factor will
seriously mitigate global warming have serious errors, from what I have
read.

There are some proposals to seed the oceans with nutrients which foster
algae growth which locks up a lot of carbon. I suspect that this may work
in short term if the algae falls to the bottom of the ocean, but in longer
term other critters may eat it and keep the carbon at the surface where it
can be released.

John M. Clement
Houston, TX

On 1/6/2014 11:59 AM, Folkerts, Timothy J wrote:
John M says
I've never understood this talking point. To first order rising
temperatures lead to rising levels of CO2 and rising levels of CO2
lead to rising temperatures. As John Denker has already
pointed out, it's a positive feedback loop.
There are a few negative feedbacks as well. A couple of
the more obvious ones to me are:

Rising temperatures --> more evaporation --> higher albedo
--> cooling
More CO2 --> plants grow better --> CO2 pulled from atmosphere -->
cooling

The warming from CO2 itself is not strongly contested
(except by some on the fringe of climate denialism).
Generally people calculate that doubling CO2 will lead to ~ 1
C warming by itself, due directly to the radiative effects of
the CO2. That is the 'simple' physics of "radiative forcing".