Humanity in transition

2005, Joel Cohen says, is the midpoint of a historic decade. Before this decade, young people always outnumbered older people; rural residents always outnumbered city dwellers; and the median number of women per child always exceeded two. By the end of this decade, none of this will ever be true again.

In a special issue of Scientific American titled “Crossroads for Planet Earth,” Cohen, who is head of Rockefeller’s Laboratory of Populations, writes about the major changes in human population over the next 50 years. His report appears alongside several others on the economic, public health, agricultural and environmental concerns facing our planet.

“Virtually all population growth between now and 2050 is expected to happen in the less economically developed regions of the world, and half the global increase will be accounted for by just nine nations, most of them in Asia and Africa,” Cohen says. “Most of that growth will be in urban areas. Poor countries will have to build the equivalent of a city of more than one million people each week for the next 45 years.”

In the short term, the Earth can provide room and food for the increased populace – we already grow enough grain to feed 10 billion people a vegetarian diet – but whether it will be a comfortable existence is a matter of politics, values, economics and distribution. “The question is whether 2050’s billions of people will be able to live with freedom of choice and material prosperity, however freedom and prosperity may be defined by those alive in 2050,” Cohen says.

Reference: Scientific American 293(3):48-55

Source: Rockefeller University