]]]]]]]]]]]]]]        PSEUDO-SCIENTIFIC HOT AIR     [[[[[[[[[[[[[[[[[    
              The data on climate are inconclusive      (12/29/1988)
                   by  Andrew R. Solow, 
       Statistician at Woods Hole Oceanographic Institute
      (From the Op-Ed page of The New York Times, 12-28-88)

              [Kindly uploaded by Freeman 07656GAED]

  Good  science  is often boring.  Good science  fiction  is  usually
exciting.   This may explain why recent stories about the  greenhouse
effect have been so exciting.
  The  typical story -- usually told by a scientist in  Congressional
testimony -- goes something like this:  Global temperature depends on
atmospheric  composition, which is affected by human activities  like
burning  fossil  fuels.   Consequently, these  activities  may  cause
atmospheric warming.  This, in a nutshell, is the greenhouse effect.
  The scientist mumbles something about being uncertain of the actual
timing, effects and magnitude of the greenhouse effect.  Then the fun
begins.   Disclaimers  aside,  the scientist goes on  to  describe  a
future of stifling heat waves, unrelenting drought and rising seas.
  The testimony is featured in the next day's papers.  The  scientist
appears  on  the  morning news programs.   Magazines  print  alarming
stories  replete with lurid graphics.  Calls for drastic action  ring
out.
  Meanwhile,  those of us who are also concerned about climate change
but  who  recognize  the enormous uncertainties  and  are  doing  the
difficult  and  (I like to think) important work  of  reducing  these
uncertainties, wistfully contemplate early retirement.
  What can we really say about future climate?  There are three  ways
of making climate predictions.  The first is through theory.
  Theory says that increasing the atmospheric concentration of carbon
dioxide  may  lead to warming.  Because the concentration  of  carbon
dioxide  is increasing, we worry about warming.  Beyond that,  we  do
not  know enough about climate processes to make  useful  predictions
from theory alone.
  The  second way of making climate predictions is  through  computer
models.  These models are large systems of equations representing our
understanding  of  climate processes.   Because our understanding  is
limited,  the  models are of limited use.  For example, these  models
have a hard time reproducing current climate from current data.  They
cannot be expected to predict future climate with any precision.
  The third  way of making climate predictions is by  using  existing
data.   Although  this  is  the  crudest way  --  the  past  being  a
potentially poor guide to the future -- existing data can, for  exam-
ple, tell us if the greenhouse effect has already begun.  Temperature
data  for  the last 120 years show an irregular warming  af  about  1
degree  Fahrenheit  over the past century.  Over some  periods,  this
warming was relatively rapid.  The 1980's has been such a period,  as
were the 1890's and 1920's.
  Because  the greenhouse effect is associated with warming, and  the
data  show  warming, can we conclude that the greenhouse  effect  has
begun?  Not unless we are prepared to believe that the only cause  of
warming  is  the greenhouse effect.  There are indications  that  the
current  warming is unrelated to the greenhouse effect.  The rate  of
warming is far below that predicted under the greenhouse effect.
  The current warming started before the greenhouse effect could have
begun.   If the greenhouse effect had begun during the course of  the
data,  then  we would see the  warming accelerate.   No  acceleration
appears  in the data.  The current warming is consistent with a  mild
post-glacial period, probably the aftermath of the so-called  "little
ice age" that ended during the 19th century.
  The conclusion is that we cannot yet make useful predictions  about
climate,  and that existing data show no evidence of  the  greenhouse
effect.   Many people will be surprised to hear that this is more  or
less  the view expressed in scientific journals,  where articles  are
subject  to  peer review.  Unsubstantiated or  misleading  statements
only  appear  in  such  journals  when  the  review  process   fails.
Congressional  testimony and interviews in the press are not  subject
to  peer  review,  and that is  how  unsubstantiated  and  misleading
statements come to dominate public discussion.
  Some  will  say  that  the  scientific  establishment  demands   an
unreasonable degree of certainty before accepting a new idea.  But in
the case of climate change, and particularly with regard to detecting
change with existing data, it is not a question of the evidence being
tenuous.  It is a question of there being no evidence at all.
  And  sone will say that if we wait until we're sure  about  climate 
change, then it will be too late to do anything about it.  Of  course 
this  argument applies equally to an invasion by aliens  from  space.  
More seriously, this argument neglects the costs of overreaction.
  Take  the consumption of fossil fuels.  Like it or not,  this  con-
tributes  to  our  standard of living.  Policies  that  curtail  such 
activities will reduce our standard of living.  For this reason, such 
policies  need better justification than current fears about  climate 
change.

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