From rmg3@access1.digex.net Fri Jul  4 19:14:33 EDT 1997
Article: 141716 of sci.environment
Path: news2.digex.net!digex.net!not-for-mail
From: rmg3@access1.digex.net (Robert Grumbine)
Newsgroups: sci.environment,talk.environment
Subject: Re: Consequences of Global Warming
Date: 4 Jul 1997 10:01:42 -0400
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References: <867946970.5708@dejanews.com>
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Xref: news2.digex.net sci.environment:141716 talk.environment:106656

In article <867946970.5708@dejanews.com>, Bill LaSor  wrote:

>Two of the
>more detailed pieces I have read recently are Jan Schloerer's
>every-other-month article on climate change, and Bob Grumbine's
>FAQ on sea level, ice, and greenhouses.  Both take a very
>cautious tone, suggesting simply that much more study will be
>required before we can know the long term consequences of climate
>change.  Yet both authors write with the seeming expectation
>that those consequences will be adverse to humanity.

  I don't know about Jan, but I've also been told that the sea level 
FAQ grossly underplays the dangers.  I have a feeling that the tone 
depends on the reader.

  Certainly, though, we both tried to present the facts as they are
known and to leave the speculation for elsewhere.  

  As already noted, climate changes naturally.  The experiment
we've embarked upon may change things faster than has been customary
in the past, which (if that does happen) would have greater
effect on the biosphere than the previous changes.  'Greater effect'
is unlikely to mean extinction of all life on the planet.  It
is likely to mean extinction of many species (and probably genus'
and families) that would otherwise have been ok.  

  Climate change isn't even likely to exterminate the human race.
But, we're already seeing the fact that the society and the economy
are built on assumptions about climate and experience with a particular
climate.  _When_ climate changes (natural or anthropogenic) 
this has been and will be disruptive of society and the economy.
If you can get copies, Stan Chagnon has studied the matter for
a couple of particular cases (insurance and, I think, farming)
published in the Bulletin of the American Meteorological Society
in the last couple of years.

>And why
>are the current boundaries of the temperate zones so sacred
>that any change should be considered ill-advised human meddling
>on a global scale?

  If you could predict exactly where the corn belt (for example)
would move to (you can't), and had accurate economic models (you 
don't) to predict exactly what the economic costs/benefits would
be, then it might be a good thing to change the climate (at least
for the corn growers).  But, we don't have the tools to make that
decision in that way.  What we do know is that farming areas are good for
reasons which take thousands of years to develop (that nice black
dirt in the midwest), and that regions to the north (mostly Canadaian
plains) don't have the soil to support the agriculture that the 
corn belt does.  Rough consideration, true, but it seems unlikely that
moving the corn belt temperature zone north will be a net gain.
(I believe one of Chagnon's articles discusses this as well.)

  Nothing 'sacred', just expensive.  In addition to lowered productivity,
you have to build the distribution system.

  Rather a lot of the effects are in this way.  With 5 meters sea level
rise, almost all of Florida goes under water.  If we get that
rise, either you spend a lot of money building dikes, or you 
spend a lot of money depopulating the state.  But it'll cost 
either way.  Won't kill millions of people, but costs are in the
hundreds of billions or more.

-- 
Robert Grumbine rmg3@access.digex.net
Sagredo (Galileo Galilei) "You present these recondite matters with too much 
evidence and ease; this great facility makes them less appreciated than they 
would be had they been presented in a more abstruse manner." Two New Sciences