COVER STORY/POPULATION

would consume how much of the planet’s resources. The threshold at which the planet would not be able to sustain a population is being debated (see ‘On the brink’). Six studies estimate two billion people; seven say four billion; 20 guess eight billion; 14 put it at 16 billion; six claim 32 billion; seven say 64 billion; another two estimate 128 billion, while one study each supports 256 billion, 512 billion and 1,024 billion people.

Consumption does not seem to be a concern. The bigger worry now is the utter inequality in consumption and, thus, in distribution of resources. “An average middle-class American consumes 3.3 times the subsistence level of food and almost 250 times the subsistence level of clean water. So if everyone on Earth lived like a middle-class American, then the planet might have a carrying capacity of around 2 billion,” writes Stephen Dovers, director of Fenner School of Environment and Society, College of Medicine, Biology & Environment, Australian National University and Colin Butler, professor, Faculty of Health University of Canberra.

The developed world consumes maximum energy and food. At the end of the 21st century, Europe and the US would have consumed 80 per cent of the world’s resources. Better economic status increases consumption. A 2009 study published in the journal has established that blaming population growth as the driver of climate change is misleading. The research

concludes: “A review of carbon dioxide emissions levels for nations, and how they changed between 1980 and 2005 (and also between 1950 and 1980), shows little association between nations with rapid population growth and nations with high GHG emissions and rapid GHG emissions growth.” A few countries, though with relatively lesser population, had caused more damage to the planet.

John Wilmoth, director, Population Division, UN Department of Economic