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Re: [Phys-l] Prof. Hal Lewis resigns from APS



John,

A question regarding the warming of late. We are on a warming trend in the ice core data, and we are not significantly off that graph in temperature (although way off the graph in CO2). Is the recent (100 years) warming obviously different from what one would expect anyway from the natural cycles? If so, how do we know that? Any resources come to mind?

Bill


William C. Robertson
Bill Robertson Science, Inc.


On Oct 13, 2010, at 9:38 AM, A. John Mallinckrodt wrote:

David Marx wrote:

Do you have a link to a peer-reviewed paper that demonstrates the link
between human emissions of CO2 (which are less than 5 % of all
emissions each year) and global warming over the past 40 years?

No. I'm not an expert in the field, but I've spent enough time looking at the data to think that a few things are close to incontrovertible:

1. CO2 levels in the atmosphere are higher by at least 30% or so than we have seen in at least a million years and that rise (over the last hundred or so years) is very clearly due to human activity.

2. CO2 is a greenhouse gas with very well known radiative forcing potential and predictions can be made about the resulting decrease in upward radiation at the wavelengths that CO2 absorbs.

3. We do, indeed, see very close to that expected decrease in upward radiation in satellite observations.

4. We know the sensitivity of the climate in terms of degrees of increased equilibrium temperature per watt per square meter of of increased radiative forcing.

5. Over the past twenty years we have seen roughly the amount of warming to be expected from all of the above.

John Mallinckrodt
Cal Poly Pomona
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