Human consumption plans are part of the problem (Image: Alex Wong/Getty)

THERE is a pervading myth that efforts to fight climate change and other environmental perils will be to no avail unless we “do something” about population growth. Even seasoned analysts talk about the threat of “exponential” population growth. But there is no exponential growth. In most of the world fertility rates are falling fast, and the countries where population growth continues are those that contribute least to our planetary predicament.

Back in the late 1960s, when Paul Ehrlich wrote his seminal book The Population Bomb, rapid population growth was arguably the number 1 threat to the planet’s future. Many believed that only strict birth control could prevent doomsday. But after scandals about forced vasectomies in India and China’s draconian one-child policy, such views fell into disrepute. What’s more, Ehrlich’s prediction of hundreds of millions of deaths from famine in the 1980s fortunately failed to be borne out.

Now the demographic monster has become a hot topic again. Yet the arguments still don’t fit the reality. The population “bomb” is fast being defused. Women across the poor world are having dramatically fewer babies than their mothers did – mostly out of choice, not compulsion. Half a century ago, the worldwide average for the number of children a woman had was between five and six. Now she has 2.6. In the face of such a fall it is hard to see what more “doing something” about global population might achieve.

Half the world now has a fertility rate below the replacement level, which, allowing for girls who don’t make it …