Re: [Phys-l] Climate skeptic convinced by data. Was: Re: Mike Mann _The hockey stick and the climate wars_

[Hugh Haskell <haskellh@verizon.net>]

At 1:33 PM -0700 2/18/12, John Denker wrote:
> I'm sorry to pick out one sentence that I don't entirely agree
> with, but here goes:
>
> >   it is probable that at least much of the
> >  change can be mitigated by increasing the earth's albedo, which is a
> >  bit of geoengineering that we can do and probably can control.
>
> The "control" part is still open to question.

I don't disagree with JD's quibble about my comment on albedo change 
as a controllable bit of geoengineering. I probably should have use 
the adjective "possible" instead of probable. In general, I am not a 
fan of the approach to solving the problem by geoengineering. It is a 
dangerous game and controlling it will probably be more difficult 
that anyone realizes.

What I had in mind when I made the remark are things like Art 
Rosenfeld's "White Roofs" project (Google it if you're not familiar 
with it). If we can make small changes in the earth's albedo with 
projects like that, we may be able to have some effect on global 
warming, but it isn't certain that it can have a measurable global 
effect, although Rosenfeld's calculations show that it can certainly 
have local effects when well-implemented. I'm sure there are other 
projects like white roofs that could have additional effects like 
this, although I have no examples at hand at the moment. Big projects 
like lower CO2 emissions amount in a practical way to geoengineering 
although they usually don't get included in that category, primarily, 
I assume, due to the fact that they are, from a climate POV, 
"passive" instead of "active" (like the space-shades at the LaGrange 
point between the earth and the sun), or seeding the atmosphere with 
CO2-absorbent chemicals.

Doing things like reducing GHG emissions don't change the earth's 
albedo (as I understand the meaning of that word) because the 
greenhouse process is not strictly a reflectivity alteration, even 
though its effect is functionally the same--that is, attempting to 
restore the energy balance between the sun and the earth by 
increasing the fraction of solar energy which is ultimately 
re-radiated into space, and thus restoring the (average) balance 
between incoming and outgoing radiation that is needed to keep the 
earth (on average) at equilibrium with its surroundings.

Hugh

--
Hugh Haskell
mailto:hugh@ieer.org
mailto:haskellh@verizon.net

I have been wondering for a long time why some of our own defense 
officials do not
put more emphasis on finding a good substitute for oil and worry less 
about where
more oil is to come from.  Our people are ingenious. New discoveries 
are all around
us, and when we have to make them, we nearly always do.

						Eleanor Roosevelt
						February 13, 1948