Environmental Engineering Reference
In-Depth Information
Climate Modeling
u
.
Introduction
Scienti
s
climate extend back into the nineteenth century.
Com-
puters did not exist, and all calculations had to be done by
hand. It was known back then that water vapor was an
essential element in the Earth
c efforts to understand changes in the Earth
'
s energy budget and had to
be taken into account in any attempt to calculate what the
climate might do. Carbon dioxide, one of several known
greenhouse gases, was recognized as being particularly
important because of its abundance and because it blocks
outgoing radiation in some wavelengths where water
vapor does not.
There was little concern about climate change until the
'
s when two things happened to wake us all up. Roger
Revelle, then Director of the Scripps Institute of Ocean-
ography in San Diego, California, calculated that seawater
could only absorb carbon dioxide at one-tenth the rate
that scientists had thought, and Charles David Keeling
showed that CO
in the atmosphere was increasing faster
than anyone had thought possible, a
finding that agreed
with Revelle
'
s analysis. This was a double hit: CO
stayed
Spencer Weart has posted a splendid detailed history of climate
modeling at
www.aip.org/history/climate/
. He has also documented the
history of the
s revolution led by Revelle and Keeling at
www.aip.
