Global concerns on human settlement and cross-cutting issues in living environments

摘要

The total population of the world reached 7 billion in October 2011, and the United Nations has forecasted that the world population in 2050 will be around 9 billion. What are the environmental implications of rapid population growth? Globally, over half of the world's population (54%) lives in urban areas in 2014 although there is still substantial variability in the levels of urbanization across countries. If we review the history, in 1800, only 3% of the world's population lived in urban areas. In 1900, almost 14% of populations were urbanites and in 1950, 30% of the world's population resided in urban centres. The world has been experiencing unprecedented urban growth in recent decades. The coming decades will bring further profound changes to the size and spatial distribution of the global population. The continuing urbanization and overall growth of the world's population is projected to add 2.5 billion people to the urban population by 2050, with nearly 90% of the increase are being concentrated in Asia and Africa. At the same time, the proportion of the world's population living in urban areas is expected to increase, reaching 70% by 2050.