Urban sustainability has been debated in the past few years. More than 54 percent of world population are living in urban areas and economic activities are centred in the urban areas. Sustainability of urban areas of developing and developed nations has been linked to their environment and economy. Cities account for 55 percent of GDP in low income countries, 73 percent in middle income countries and 85 percent in high income countries. According to UN projection, 2.5 billion more people will be added to the world’s urban population by 2050 and 90 percent will be concentrating in Asia and Africa. Increasing urban population leads to increased demand of energy, water and other resources questioning sustainability of the city. Environmental problems such as air and water pollution have aroused in cities and vulnerabilities to climate change have increased.
Higher levels of literacy and education, better health and social services and increased opportunities for cultural and political participation are positive aspects of urbanisation however pollution, environmental degradation, unsustainable production and consumption patterns are pitfalls. Global change factors such as economic change, scarcity of resources, rapid technological and social change, environmental and climate change affects have been questioning sustainability of the cities. Higher level of income and increasing level of resource consumption leading to larger ecological footprint have been caused by unchecked urbanization. Rising number of slum population in the urban areas of developing countries and increasing ‘urban-divide’ or social and economic inequality among urban populations need to be addressed to ensure sustainability.
Policy measures such as equitable and sustainable share of the benefits of urban growth, planned and managed spatial distribution of the urban population, balanced distribution of urban growth, access to urbanization trend information must be taken to minimize adverse effects of urbanization.
Effective leadership, political commitments, the process of learning, participation, negotiation and co-ordination are required to drive cities towards sustainability. Planned developmental projects, capacity building and institutional strengthening have been necessitated to maintain sustainable practices and behaviours.