Sustainability and the City

CHAPTER 1

The City Revolution

Today, more than 50 percent of the world’s population lives in urban areas, compared to just 3 percent in 1800 and 30 percent in 1950, and that proportion is expected to increase to 66 percent by 2050 (The World Population Prospects 2015). Moreover, populations of the 20 most populated cities in the world increased by 64 percent from 1990 to 2014. Reflecting a similar trend, there were only 83 cities with populations exceeding one million in 1950, and by 2007, this number had risen to 468 (City population Retrieved 2010). In addition, more than 70 percent of the populations of North America and Europe reside in urban areas (Gibson 2007).

But what is a city? The concept of city is very difficult to define. From a ...