Assessment of Impacts of Developmental Pathways on Air Quality in the Urban Sprawls in South and South-East Asia

The developmental processes in the urbanization are the important drivers for determining the quality of ambient air, which is often a result of interactions of various socio-politico-economic activities being pursued in urban areas. These interactions also influence the extent of emissions of various greenhouse gases and other air pollutants not only in the urban areas but also in the surrounding areas, which cater to the various kinds of needs of urban centres. This paper presents the results of a study being carried out by a team on the impacts of developmental pathways on the emission of different pollutants in urban sprawls extending from Indo-Gangetic Plains area in the west to Mekong Delta region in the east, thus covering a sizable section of Asia. For this study, cities like New Delhi, Metro-Manila, Ho Chi Minh city, Jakarta and Chiang Mai of this region have been selected for carrying out the case studies. This mix of cities represents a variety of socio-economic backgrounds ranging from predominantly agriculture based to mid-sized urban centers to large urban agglomerates thus providing opportunity to study the consequences of different pathways of regional development on amount and mixture of key air emissions including greenhouse gases. The basic objective of this study is to understand the underlying social and political causes and constraints influencing the emissions of air pollutants. In this study, both direct and deemed emissions have been estimated for the target cities. The results have indicated that in most of the cities, transport and the industrial sectors are the major contributors to the overall emissions from the cities and urban sprawl is responsible for increasing the transport sector emissions due to increased demand for transportation. The economic prosperity is another driver, which is increasing the emissions of pollutants but also simultaneously exerting pressure for use of cleaner technologies. The economic prosperity also induces the preference for personal mode of transport. In spite of the adoption of various corrective measures by the concerned stakeholders in these cities, the trends of emission of most of the pollutants are still increasing although in some cases efficiencies have increased. The per capita CO2 emissions for most of these cities have been estimated to be in the range of 0.4-0.8 tons/year for the year 1995 which have gone up to 0.7-1.1 tons/year in 2000. However, these per capita CO2 emissions are still less than the estimates for other Asian mega-cities like Tokyo, Beijing, Shanghai and Seoul where the values range from 4-8 tons/year for the year 2000.