More than half of the world’s total population, currently roughly 7 billion, now lives in cities. As the world’s population increases to a projected 9 billion by 2050, so too will the trend toward greater urbanization. Urban growth is most rapid in the developing world, where cities grow by an average of 5 million residents every month. By 2050, urban dwellers will likely account for 67 percent of total population in the developing world and 86 percent in the developed world.
Many of the world’s cities, and some of its biggest, may be particularly vulnerable to climate change and the expected rise in global temperatures. In metropolitan centers like Dakar, Delhi, New York, Sao Paulo, Shanghai and Tokyo, average temperatures are projected to rise between 1 and 4 degrees Celsius by 2050. Climate change is expected to lead to greater droughts in some areas, as well as greater storm surges, flooding from glacier melt and rainfall, and rises in sea level. It is estimated that by the end of the century, “seas will climb 80 centimeters or roughly 2.6 feet.”
According to the Intergovernmental Panel on Climate Change (IPCC), the Middle East and North Africa region is particularly vulnerable to climate change impacts. If temperatures increase up to 4 C by 2050, the results could be a 20-30 percent decrease in water availability. Meanwhile, in North African urban hubs, a temperature increase of up to 3 C could expose up to 25 million people to flooding.