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

John Mallinckrodt wrote:

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.

I think most people will certainly agree with points 1 and 2. The other 3 points are less well
established, particularly number 5. The actual dynamic processes are much more complex than your
simple model indicates. It doesn't take into account the numerous positive and negative feedbacks
that exist (most of which are porrly understood at best).

Since the land and sea temperature data is very inaccurate and the historical measurement record is
somewhat incomplete and unreliable, we are left with the satellite temperature measurements since
1979. These are updated monthly from UAH. Please see this website for this data. Are you saying
that the continuous increase in CO2 correlates well with the observed global temperature changes