'Overpopulation'

"The biggest single challenge facing the Earth…is not global warming. That is a secondary challenge. The primary challenge facing our species is the reproduction of our species itself."

Boris Johnson, The Telegraph 

Demographic language is a semantic minefield. Talk of 'overpopulation', a condition that will arise when the ratio of humans to Earth's available resources is too high to sustain everybody, is fraught with controversy over geopolitics, sex, power, gender, race, religion and personal rights -- as well as 'simple' factual accuracy.

Doom and boom

Whether overpopulation exists or will exist depends entirely upon whom you believe. The debate rages between neo-Malthusian doomsters -- who point to the necessity of winnowing the world's population to prevent the planet's resources being gobbled by too many people -- and the cornucopian boomsters, who argue that higher population density leads to technological innovation, and thus a higher standard of living. 

Jeremiahs -- such as Paul Ehrlich, an author on the subject of human overpopulation -- have been wide of the mark in their predictions. In the late 1960s and  early 1970s, Ehrlich wrote that the population of the US would shrink from 250 million to about 22.5 million before 1999 because of famine and global warming. He did not account for the Green Revolution, which saw world grain production increase by 250%.

Others argue the world is a deep enough breadbasket to sustain further population growth. Julian Simon, a writer of a conservative libertarian persuasion, predicted in the late 1990s that any poor country that chose to adopt property rights, science, technology, industrialisation, modern agriculture, hydroponic farming, nuclear power, and desalination, would achieve a rich, first world standard of living, even if Earth had tens of billions of people.

Population control

Doomsters such as Boris Johnson, a British MP and Conservative candidate for mayor of London, urge 'population control.' The term has fallen from favour, because it implies force, writes the United Nations Fund for Population Activities (UNFPA).

If there are too many people populating the planet, who is surplus to requirements? Americans may constitute approximately 5% of the world's population, but they produce nearly a quarter of the world's carbon dioxide, consume a quarter of the world's resources, including approximately 26% of the world's energy, and generate approximately 30% of the world's waste.

Nevertheless, 'population control' will not take place in the United States, but in less developed regions, where most population growth occurs:

• The UNFPA prefers virtuous euphemisms for population control such as 'stemming,' 'stabilising' or 'slowing' population growth.
• 'Family planning' and 'birth spacing' are preferred to 'birth control.'
• The organisation also focuses on 'sustainable development,' increasing the earth's 'carrying capacity' and the human 'quality of life' quotient, to stress a broader vision of global well being.  

Population bomb?

The term 'population bomb' is also discredited.

The graph shows that 'population momentum' is a better description of current and future growth.  The world's population growth rate peaked in the early 1970s; if there has been a bomb, we are living in the fallout. The global population doubled from 3 billion in the 1960s to 6 billion in mid-1999, and continues to rise -- but at a slower rate. Predictions will now centre on when the world will achieve 'population stabilisation' – ie when growth stops.