The impacts of climate change on Asia will place additional stress on socioeconomic and physical systems. These pressures may induce change in demographic processes. Demographic trends, including the stability and size of populations, will be influenced directly through the impacts of climate change on human health as described in Section 11.2.5 and indirectly through the impacts of climate change on food security and the viability of natural resource-based economic activity. A further demographic response will come about through the risk of extreme events on human settlements. If the incidence and magnitudes of events such as droughts and coastal floods increase, there could be large-scale demographic responsesfor example, through migration. Migration in itself is not necessarily a signal of vulnerability to present-day extreme events. Motivations for migration are diverse; much rural-to-urban migration in Asia takes place as a result of increased economic opportunities in megacities (cities with at least 8 million inhabitants). Future increases in the frequency and intensity of severe weather systems as a consequence of climate change can trigger mass migration, however.
The annual rate of growth in migration on a global scale has been greatest in developing countries of south and southeast Asia. For instance, population growth and land scarcity has encouraged the migration of more than 10 million Bangladesh natives to neighboring Indian states during the past 2 decades. This migration has been exacerbated by a series of floods and droughts affecting the livelihoods of landless and poor farmers in this region. Land loss in coastal areas resulting from inundation from sea-level rise as a result of climate change is likely to lead to increased displacement of resident populations. Many south Asian countries increasingly expect the number of internally displaced persons to rise in future.
Immigrant labor often benefits both the donor and the host cities/ countries (Connell and Conway, 2000). However, perceptions of regional/national identity, language/cultural differences, and fears of unemployment may contribute to increased hostilities between immigrants and nationals in years to come. Climate change will act in parallel with a complex array of social, cultural, and economic motivations for and impacts of migration (Pebley, 1998; Conway et al., 2000; Kates, 2000). Irrespective of resource constraints in developing countries of Asia, they have to better equip themselves through appropriate public education and awareness programs with disaster preparedness measures, including infrastructures for effective resettlement of displaced people as a consequence of weather calamities.
The urban population in Asia is growing at four to five times the rate of the rural population. At this rate, more than 60% of the people in Asia will be living in towns and cities by 2015. An estimated 80% of the increase will occur in developing countries. The number of megacities in Asia would grow to at least 23 of the world's 36 by the year 2015 (United Nations, 1998). Urbanization is rapid in fast-growing economies of south and southeast Asia, where the average annual urban growth rate is more than 4%. The current pace and scale of change often strains the capacity of local and national governments to provide even the most basic services to urban residents. An estimated 25-40% of urban inhabitants in developing countries today live in impoverished slums and squatter settlements, with little or no access to water, sanitation, or refuse collection (World Bank, 1997).
Basic infrastructure demand in urban corridors is likely to increase dramatically in the future. Already governments in several developing countries of Asia are introducing suites of acts and laws to ensure provision of adequate public services and minimize adverse effects on surrounding communities and ecosystems. For instance, Indonesia introduced the Spatial Use Management Act in 1992 for the identification of environmentally sensitive areaswhere development activities would be restrictedand for improved planning for the location and support of activities such as industrial development (Djoekardi, 1995). Developing countries in Asia would soon need to develop new priorities and policies that try to address demands created by the increasing number of people in cities while capitalizing on the benefits of urbanization, such as economic growth and efficient delivery of services. Climate change has the potential to exacerbate basic infrastructure demands of urban inhabitants in many countries of Asia.
Other reports in this collection