Automotive emissions in developing countries-relative implications for global warming, acidification and urban air quality

This paper attempts to assess the magnitude and scope of automotive pollutant emissions in developing countries and their role in global warming, regional scale air pollution and urban air quality. Greenhouse-gas emissions (CO2 and CFCs) from motor vehicles in developing countries contribute less than 3% to the global greenhouse effect, compared to a 9 to 12% contribution from motor vehicles in OECD countries and Eastern Europe. The share of OECD countries in conventional pollutant emissions from motor vehicles exceeds the combined contribution of all developing countries by a factor of three to five. Acid deposition from motor vehicle emissions does not currently appear to be a problem in developing countries. The incidence of regional scale ozone is not known but could be potentially significant downstream from large urban centers. There is a need for more systematic monitoring and evaluation of acid deposition and regional ozone concentrations in developing countries. Urban air quality is the prime casualty of motorization in developing countries. The air pollution problem will intensify in developing countries with increasing urbanization and the rapid pace of motorization. Urban concentrations of carbon monoxide, airborne lead, particulate matter and sulfur oxides in many developing countries already exceed the levels in industrialized countries. Motor vehicles emit 30% to 85% of all man-made air pollutants in the large urban areas in developing countries, depending on the level of motorization. Without effective measures to control pollutant emissions, some 300 to 500 million city dwellers in developing countries will become exposed to unhealthy and dangerous levels of air pollution from motor vehicles by the year 2000.