I am an atmospheric and climate scientist with a career-long interest
in understanding how the climate system works. I centered my earliest research,
in the late 1960s, on direct analysis of available observations to isolate
the most important mechanisms governing atmospheric behavior. It made me
very much aware that the available atmospheric measurements and accompanying
atmospheric theory are not sufficient to provide the deep quantitative
understanding that is required to predict changes within the climate system.
It was already clear to me that mathematical models would have to be added
to gain deeper understanding and improved predictive skills.
In 1970, I joined National Oceanic and Atmospheric Administration's (NOAA)
Geophysical Fluid Dynamics Laboratory (GFDL) at Princeton University, which
was leading the world in the new effort to use mathematical
modeling approaches to understand the entire climate system and how
it changes. GFDL was attempting to include and understand various parts
of the climate system, including such key aspects as the ocean and land-surface
systems. My task was to emphasize the stratosphere and the climate effects
of atmospheric chemistry, including ozone, a gas that absorbs solar and
infrared radiation efficiently. I soon learned that reconciling theory
and observations through the use of mathematical models is essentially
the only way to achieve a fully quantitative understanding of the climate
system. More importantly, I also learned that the challenges to be overcome
through the use of mathematical models are daunting, requiring the efforts
of dedicated teams working a decade or more on individual aspects of the
climate system.
It is this high degree of difficulty and complexity that provides significant
context for this personal essay on human-caused "greenhouse warming"
2 and some of its broader
implications. The climate system is sufficiently complex and all encompassing
that there are no "all-knowing" experts on this problem. However,
teams of talented scientists working together can, and do, become close
to the equivalent of an encompassing expertise. I am fortunate to be surrounded
at GFDL by a team of world-renowned scientists who are knowledgable about
almost all aspects of greenhouse warming. Most of the insights I offer
have been gained from a research lifetime of fruitful encounters with this
extraordinary group of colleagues.
2In this
article, the term greenhouse warming is used to describe the general warming
of Earth's climate in response to human-produced emissions of carbon dioxide
and other greenhouse gases such as methane, nitrous oxide, and the chlorofluorocarbons.