Fear Of An Urban Planet

"Will Planet Earth be able to handle the mega-surge of people pouring into the cities of Africa, Asia and Latin America?

Back in 1950, there were 2.2 billion of us, mostly spread across the world's rural areas. Today the United Nations estimates world population at 6.6 billion. Half live in cities, where an accelerating human flood of rural people — many desperately poor — generates slums, endangers water and sewage systems, and breeds local misery and potential pandemics.

If today's birthrates continue unaltered, U.N. figures suggest there could be 11.7 billion people by 2050.

There is some good news here. Birth rates have declined as rural people migrate into cities and have fewer children than farm and rural families typically do. The mid-range population expectation for 2050 is 9.1 billion.

The problem is that the global population base has increased so radically that even seemingly modest birthrates can have momentous consequences. Cohen calculates that if we do add 2.5 billion people by 2050, then the world will have to build one city of 1 million people every week for the next 43 years.

One sort of shudders at the answer. But there is a first step: Get a handle on growth of the world's cities."