The Future of Atmospheric Chemistry Research Remembering Yesterday, Understanding Today, Anticipating Tomorrow (2016) / Chapter Skim
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2 Remembering Yesterday
2 Remembering Yesterday
Pages 27-40
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From page 27... ...
Further research improved predictive capability to inform policy choices and responses to the problem, with research continuing to inform the status of the problem today. A brief history of these examples and the central role played by atmospheric chemistry research and researchers, including those whose contributions were recognized with the Nobel Prize and the U.S.
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From page 28... ...
. In his classic book Photochemistry of Air Pollution, Philip Leighton described the fundamental reaction mechanisms involved (Leighton, 1961)
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Harold Johnston studied fundamental reaction mechanisms and kinetics of nitrogen oxides (NOx) and showed that NOx emissions from stratospheric aircraft would have dramatic consequences in terms of depleting the protective upper atmosphere ozone layer.
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The lessons learned from reducing air pollutant levels in the United States provide a scientific foundation for other areas in the world where emissions have increased FIGURE 2.1 Trends in percentage deviation from National Ambient Air Quality Standards (NAAQS) for ozone, particulate matter smaller than 2.5 and 10 micrometers in diameter (PM2.5 and PM10, respectively)
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The graph shows decreasing air pollutant emissions over time since passage of the Clean Air Act, despite growth in U.S. population, economy, energy use, and miles driven.
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For example, in 1852, chemist Robert Smith coined the term "acid rain" when he noted higher acidity rainfall in industrial regions relative to coastal areas in England and indicated it was a result of sulfuric acid from coal combustion (Smith, 1852)
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From page 33... ...
This realization resulted in the 1980 Acid Deposition Act, which was passed to comprehensively support a program addressing the sources of acid rain and dry deposition and their long-term effects over a broad geographic area. Research was also funded to examine potential pollution control measures, which resulted in Clean Air Act amendments and supporting legislation such as the Cross-State Air Pollution Rule1 to ameliorate effects of pollutant transport between states.
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From page 34... ...
can react, they are inert in the lower atmosphere and do not contribute to photochemical air pollution. However, their long lifetimes in the lower atmosphere mean that they can reach the stratosphere where they absorb short-wavelength ultraviolet radiation, generating highly reactive chlorine atoms.
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, and Paul Crutzen (right) laid the groundwork for understanding ozone depletion in the stratosphere.
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From page 36... ...
. The integration of laboratory studies, theory, models, and field observations built a detailed understanding of the phenomena responsible for stratospheric ozone depletion, including the unique chemical processes that led to formation of the Antarctic ozone hole (Cicerone et al., 1983; Molina and Molina, 1987; Prather et al., 1984)
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. These graphs show past increases in ozone depleting substances as well as the dramatic impact of the Montreal Protocol to curb production and release of CFCs, which are now declining in concentration.
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2.2 CONCLUSION As discussed in the three case studies presented in this chapter, the results of atmospheric chemistry research have historically provided a strong foundation of scientific understanding of issues that affect human and global welfare. This understanding has enabled the identification of the root causes to major problems and the development of predictive capabilities that informed scientifically based control strategies.
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From page 39... ...
, similar to the emergence of the Antarctic ozone hole. The ability to stay ahead of rapidly evolving environmental issues will require having a range of the most advanced tools possible in order to be ready to respond to the next event, be it a volcanic eruption, an oil spill, or emissions of methane from destabilizing permafrost.
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