From STEPHEN H. SCHNEIDER
In Talking Point (9 March), William Nierenberg (co-author of the 1989
George C. Marshall Institute report which downplays the seriousness of global
warming) made the improper claim that in 1980 Robert Chen and I ‘estimated
a rise in sea level of 25 feet based on a doubling of carbon dioxide in
as little as tens of years’, whereas today most estimates suggest less than
one meter sea level rise in a century.
I wonder whether he, or anyone at the Marshall Institute who has made
this claim elsewhere, has ever read that paper? Otherwise, they would have
known that Chen and I predicted nothing. We simply did an impact assessment
based on the then uncertain discussions among glaciologists about the timing
and magnitude of any West Antarctic deglaciation. All of these caveats were
clearly spelled out in the beginning, conclusions and body of the (1980)
Schneider and Chen paper.
It disturbs me that only an institution with a political agenda could
distort that stated purpose into a prediction in order to impugn our credibility
10 years later. Incidentally, research since 1980 suggests a strong possibility
that warm ocean temperatures could dramatically increase the intensity and
the length of the season for severe tropical cyclones. This could substantially
increase the probability of now rare events, such as 15 to 25 foot storm
surges. In other words, our 1980 coastal flooding impact assessment may
still have value, but from different physical reasoning – a possibility
never mentioned by Marshall Institute authors.
Our published conclusion in Schneider and Chen (1980) was that if such
a sea level rise did occur, and it took 150 years (not 10 years), then at
7 per cent per year discount rate even that very large sea level rise would
be ‘worth’ only some $30 million today. We then raised philosophical questions
about the appropriateness of such discounting in the global warming context.
We concluded (and still agree) that:
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‘We recognize that quantitative assessment of a relatively far away
problem like the sea level rise case may be less useful for immediate decision
making in society than a qualitative assessment of a potentially more significant
problem like food production variations. But the general efforts at climatic
impact assessment must, we believe, expand considerably, and the hypothetical,
but plausible, sea level rise is a tangible case study. We hope many other
studies will follow. At the same time, we believe it is not premature to
begin to consider steps to minimize our vulnerability both to carbon dioxide-induced
climatic changes and to any future shifts away from fossil fuels. It is
in this spirit that we wish our efforts here to be interpreted.’
Any other interpretation, such as those previously given by Marshall
Institute authors, both distort our clearly stated views and call into question
the scholarship of the critics, if not their motives.
Stephen H. Schneider National Center for Atmospheric Research Boulder
Colorado
