stan to the United Nations Framework Convention of Climate Change," www.unfccc.int (cited January 2008).
Ingrid Hartmann Independent Scholar
Keeling, charles David (1928-2005)
CHARLES DAVID KEELING was a pioneer of climate science and atmospheric monitoring. Through his work at the Scripps Institution of Oceanography, Keeling constructed the most extensive record of atmospheric levels of carbon dioxide (CO2) ever produced. Keeling's careful charting of rising concentrations of CO2 in the Earth's atmosphere served to confirm scientific theories about the impacts of industrialization on the global environment and provided the empirical cornerstone for subsequent analyses of climate change.
Born in Scranton, Pennsylvania on April 20, 1928, Charles David Keeling studied chemistry at the University of Illinois (graduating in 1948), before obtaining his Ph.D. (also in chemistry) from Northwestern University in 1954. His move into atmospheric studies was confirmed in 1956, when the Scripps Institution of Oceanography recruited him to work on a new research program exploring the complex links between CO2, global warming, and ocean systems. Keeling's initial work at Scripps was guided by the oceanographer Roger Revelle, who at the time was the director of the Institution of Oceanography. As an early advocate of the theory of an enhanced greenhouse effect, Revelle's work proved that the heightened levels of CO2 produced by industrial society would not be absorbed, to any significant extent, by the oceans. This observation brought in to question the conventional wisdom of the early post-war period that anthropogenic CO2 would be absorbed by ocean systems, plant-life, and other carbon cycle sinks, thus maintaining the global atmospheric balance of CO2. It was, however, the assiduous work of Charles David Keeling that would confirm this crucial scientific theory.
Following his arrival at Scripps, Keeling worked to establish the necessary monitoring sites and equipment that would facilitate the accurate measurement of global atmospheric ratios of CO2. With the support of the Environmental Sciences Services Administration of the U.S. government, Keeling was able to collect research data from two remote, pristine air locations: the Mauna Loa Observatory, Hawaii, and a monitoring station established at the South Pole. The use of pristine air-monitoring locations was crucial to Keeling's work. The fact that the Mauna Loa and South Pole monitoring stations were located at great distances from major local anthropogenic and biotic sources of CO2 meant that they could provide accurate measurements of global changes in atmospheric CO2 concentrations (although the Hawaii station was subject to occasional spikes in CO2 created by local volcanic activity and vegetation).
In addition to securing the sites necessary to monitor global fluctuations in atmospheric CO2, Keeling was also involved in developing the techniques and instruments that were needed to actually measure CO2 in the atmosphere. The method deployed by Keeling for measuring air-borne CO2 involves passing air through an aluminum tube using a diaphragm pump, and then forcing the air through a filter, to remove water vapor, after which an infrared analyzer tests the air sample. The assiduous monitoring of atmospheric CO2 at Mauna Loa and the South Pole by Charles David Keeling and his colleagues 1958-2005 provided fascinating hourly, daily, and seasonal records of CO2 fluctuations. It was, however, only when the biannual concentrations of atmospheric CO2 were plotted over a longer time that the dramatic implications of Keeling's work become apparent. The so-called Keeling Curve that emerges from such a time-sequenced data plot reveals the inexorable rise of CO2 in the atmosphere from 1958 to the present day. In discussing the ominous simplicity of the Keeling Curve, Michael McCarthy recently described it as one of the key images in human history.
Beyond his contribution to assessments of the changing fractions of CO2 present in the atmosphere, Charles David Keeling took a holistic interest in the operation of the carbon cycle and the broader problems associated with air pollution. In relation to the carbon cycle, Keeling was at the forefront of attempts to accurately model the flow of carbon and
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