1.1.1 World urbanisation
Today, more than half of the world’s population, 3.5 billion people, live in urban areas, and by 2030 this will rise to 60%. Over the next decades there will be significant changes in the size and distribution of the world’s population.
According to the United Nations (UN) close to half of the urban population live in cities of less than 500,000 people, but one in eight of us live in 28 mega cities – cities that have more than 10 million inhabitants, such as Tokyo, Delhi, Shanghai, Sao Paulo and London. The fastest growing cities have 500,000 to 1 million inhabitants and are located in Asia and Africa (UN, 2014).
Rapid urbanisation and unplanned growth pose significant challenges – greater demand for natural resources such as water and energy, increased pollution and impacts on biodiversity. The world’s cities occupy just 2% of the Earth’s land, but account for up to 80% of energy consumption and 75% of carbon dioxide emissions (UN, 2014).
Cities are major contributors to climate change but they’re also heavily vulnerable to it: they’re affected by rising sea levels, more frequent and stronger storms and cyclones, and more frequent extremes in heat and cold. These then impact on urban infrastructure and quality of life.
In many cities there’s also a shortage of housing, pressure on healthcare systems, and issues with poverty and crime.
Cities in the developing world face the toughest challenges, and it is here that 95% of future urban growth is predicted to take place by 2050. These cities will experience great change but have the lowest levels of resources and institutional capabilities to deal with that change. Already, 828 million people live in slums and the number keeps rising (UN, 2015).
However, the high concentration of people in cities can also bring benefits: if managed well population density allows increased access to jobs and cultural activities as well as to services such as healthcare, education and mobility, which could lead to longer life expectancy and poverty reduction.
Cities are dynamic places. They rely on the flow of people, ideas, resources and global connections. To thrive, cities need to meet the economic and social aspirations of the people who live there. They also need to manage their impacts on the environment in order to ensure that their growth is sustainable and that benefits are accessible to all.
If you want to learn more about the UN’s interest in cities and sustainability, check out this site: United Nations World Urbanization Prospects.. Explore the work of the UN’s Department of Economic and Social Affairs in this 2014 report (revised)