The Difficulty of Forecasting Ambient Air Quality— A Weak Link in Pollution Control

This article examines one important component of the problem of implementing the federal government's Clean Air policy, namely, the difficulty of quantifying the relationship between emissions to the atmosphere and ambient air quality. Short-, middle-, and long-term control strategies are discussed with an emphasis on the information needed for their effective assessment and implementation. The requirement thus identified is compared with the information provided by air pollution models; it is shown that at their present stage of development, even the most sophisticated diffusion models are of limited usefulness in implementing current air pollution legislation. In view of the high cost of pollution control, further investment in model development is thought justifiable, though there are significant problems to be overcome. It is suggested that for the time being, panels of experts might be used to make air quality forecasts.