Global air quality and pollution

Abstract

The impact of global air pollution on climate and the environment is a new focus in atmospheric science. Intercontinental transport and hemispheric air pollution by ozone jeopardize agricultural and natural ecosystems worldwide and have a strong effect on climate. Aerosols, which are spread globally but have a strong regional imbalance, change global climate through their direct and indirect effects on radiative forcing. In the 1990s, nitrogen oxide emissions from Asia surpassed those from North America and Europe and should continue to exceed them for decades. International initiatives to mitigate global air pollution require participation from both developed and developing countries. When the first measurements of high concen-trations of CO over tropical Asia, Africa, and South America were made available by the MAPS (Measurement of Air Pollution from Satellite) instrument launched in 1981 on the space shuttle Columbia (1), it became clear that air pollution was an international issue. Those images showed not only that industrial air pollution from fossil fuel combustion could affect regional and global air quality, but that emissions from biomass burning (for-est fires, agricultural waste burning, and veg-etable fuel combustion) were important as well, confirming the hypothesis of Crutzen et al. (2). This meant that people in less devel-oped countries, as well as residents of indus-trialized and rapidly growing developing countries, could suffer from air pollution gen-erated elsewhere. Another illustration of the global character of air pollution came from measurements of tropospheric ozone made b