Population in the world is currently growing at a rate of around 1.13% per year, with the average population estimated to increase by around 80 million per year. Every one of those people will need water to drink, food to eat, clothing to wear and a shelter to live in. Many of them will also want to own cars, make phone calls, travel by jet and visit shopping malls. Will the planet be able to support the demand? Will there be enough resources to go around?

The world population reached one billion in 1804, two billion in 1930 and four billion in 1974. Had it continued to accelerate at this rate, there would soon have been standing room only. Fortunately, although the world population is still increasing, the rate of increase is now declining, with the population expected to reach 9 billion by 2038 and 10 billion in the year 2056. Much of the growth will occur in developing countries, and population is actually declining in some parts of the world including Japan, Russia and parts of Europe.

See also Food and water.