Global patterns of urban population growth are recorded fairly accurately and predictions put the number of people living in urban areas in 2030 at 1.47 billion higher than it is now. But how urban areas evolve to accommodate such great numbers has never really been researched, until now.

For the first time researchers have studied how fast urban areas are growing worldwide and what their future growth may be. The research team from Yale, Arizona State, Texas A&M and Stanford expect that globally urban areas will expand by 950,000 square kilometres by 2030.

Driving factors

Urban land expansion is driven by different factors depending on location. In China it is mainly driven by a rising middle class that wants accommodations fitting their new income. In countries like India and Africa it is primarily population growth that requires the growth of cities.

Implications

The team anticipates cities’ development to take place in the most biologically diverse areas like savannahs, forests and coastlines, which according to the scientists will have large implications for biodiversity conservation, loss of carbon sinks, habitat loss and local and regional climate.

But it is not just the environment that will suffer from the rapid increase in urban area. The study in PLos ONE shows that expansion is fastest along coast lines, which is one of the most vulnerable areas possible, as recent events have shown. This makes coastal city dwellers increasingly vulnerable to environmental disasters such as flooding, tsunamis and hurricanes.

© Jorn van Dooren | www.bitsofscience.org