Re: [asa] Re: The Hockey Stick Holds Up

From: David Campbell <>
Date: Fri Sep 12 2008 - 12:44:41 EDT

There's an advanced online report from Science of relevance to the
question of why long-term CO2 and temperature records don't exactly
match up.

Atmospheric CO2 and Climate on Millennial Time Scales During the Last
Glacial Period
Jinho Ahn and Edward J. Brook

Published Online September 11, 2008
Science DOI: 10.1126/science.1160832

Changes in global ocean circulation associated with cold intervals in
the Northern Hemisphere promoted increases in CO2 levels. Increasing
CO2 correlates closely with Antarctic temperature but preceeded abrupt
warming in Greenland by thousands of years.

The basic answer to the question is that CO2 (and associated
greenhouse gases) are one of many factors affecting the climate.
However, current rapid increases in greenhouse gases means that their
particular part of the system is promoting rapid increase in
temperature and related changes in climate. Other factors interact in
a variety of ways, often complexly, but it's still not a good idea to
try to find out by experiment just how far we can push a system that
we live in. It would be an equally bad idea to try to see just how
much solar insolation we could take up through vast solar energy
projects before the climate started causing major problems. (Not that
it is a serious risk, just a hypothetical example of how we could
meddle with a different part of the system.)

Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"
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Received on Fri Sep 12 12:45:03 2008

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