In this decade, more modeling groups were established. Research programs consisted primarily of improving existing modeling techniques through higher resolution, better parameterizations, and coupling ocean and atmospheric GCMs. Increasingly, modelers began to perform GCM-based experiments. Longer models runs, made possible by faster computers, were an important part of experimental strategies. Increasing political attention to the climate change issue, especially in the United States, raised the visibility of GCMs both inside and outside climate science.
The rapid growth of computer power during this period is illustrated by the following chart of computers used by GFDL.[1]
Computer IBM 701 1956-57 1 IBM 704 1958-60 3 IBM 7090 1961-62 20 IBM 7030 1963-65 40 CDC 6600 1965-67 200 UNIVAC 1108 1967-73 80 IBM 360/91 1969-73 400 IBM 360/195 1974-75 800 Texas Instruments X4ASC 1974-82 3000
Time Period
Relative Power
Most groups building GCMs either owned or had access to large, fast supercomputers. Greater computer power allowed longer runs, smaller grids, and larger numbers of runs.
New GCM modeling groups established during this
period include:
By the end of this period, European modeling groups -- especially the ECMWF -- had begun to mount a significant challenge to United States dominance in general circulation modeling. Unlike most of the other AGCMs built during the 1970s, the ECMWF's atmospheric GCM was built "from scratch," albeit after careful study of the major existing AGCMs, including variants of the UCLA and GFDL models.[2] Its performance was improved through a continuous cycle of testing and redesign, to the point that today ECMWF medium-range forecasts are considered the benchmark for world weather forecasting.
In the latter part of the 1970s, the National
Center for Atmospheric Research gradually abandoned the
Kasahara/Washington model. In its place, NCAR developed a Community
Climate Model (CCM), intended to serve not only modelers working at
NCAR, but the large constituency of affiliated universities
associated with NCAR's parent organization, the University
Corporation for Atmospheric Research. The Community Climate Model was
initially based on the Australian Numerical Meteorological Research
Center model and an early version of the ECMWF model. It also
incorporated elements of the GFDL models.
The NCAR CCM series of models was especially important because of the
relatively large community of researchers who were able to use it.
Versions of the model were adopted by a number of other groups in the
late 1980s.
This decade was marked by steady improvement in existing techniques, rather than major innovation. Increasingly sophisticated and computationally efficient schemes were developed for:
In this decade, the possibility of global
warming became a policy issue within scientific agencies both in the
United States and internationally. Studies were conducted by the
National Academy of Sciences, the Council on Environmental Quality,
the World Meteorological Organization, and others. Congressional
hearings called for action, and funding for climate research grew
steadily. In 1985, at Villach, Austria, an influential climate
science conference recommended policy studies of climate change
mitigation techniques, including international treaties.
In the early 1980s, the effects of smoke and dust from a superpower
nuclear exchange were tested with climate models, leading to the
issue of "nuclear winter."[3]
Action on the ozone depletion issue -- sparked by observations of an
Antarctic ozone "hole" -- produced the Montreal Protocol on the Ozone
Layer in 1985. Transboundary pollution problems, notably acid rain,
were also high on the political agenda. All of these raised public
awareness of global atmospheric problems, but the issue of climate
change did not achieve the status of mass politics until about
1988.
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[1]
Geophysical Fluid Dynamics Laboratory, Geophyscial Fluid Dynamics
Laboratory: Activities- FY80, Plans- FY81 (Princeton, NJ: U.S.
Department of Commerce, 1981).
[1] ECMWF Research Department,
ECMWF Forecast Model Documentation Manual, Internal Report No. 27,
Volume 1, ECMWF (1979).
[3]
C. Covey, S.H. Schneider, and S.L. Thompson, "Global atmospheric
effects of massive smoke injections from a nuclear war: results from
general circulation model simulations," Nature 308, no. 5954
(1984): 21-25.
C. Sagan, "Nuclear War and Climatic Catastrophe: Some Policy
Implications," Foreign Affairs 62, no. 2 (1983).
S.L. Thompson and S.H. Schneider, "Nuclear Winter Reappraised,"
Foreign Affairs 64, no. 5 (1986).
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