A touch before 2pm tomorrow, the world's seven billionth person will be born, according to the United Nations population estimating clock, which adds nearly 150 people a minute to the number of us living on this planet. Internet folk have great fun with computer programmes like the one which informed me, from my date of birth, that when I was born I was the 2,595,249,671st person alive on Earth.
But for others, the occasion is an gloomy reminder of our ecological predicament. Their argument goes something like this: more people, at the rate of an extra two every second – more mouths to feed, more environmental degradation, more species extinction, more global warming and an even bigger demand on the planet's depleting resources. We are going to breed ourselves out of existence. It is no coincidence that Seven Billion Day falls on Halloween, the scariest day in the calendar.
A man stood up at a conference the other day and told us that over-population was the problem which underlay all others. Nothing would improve until effective population control was put in place. Should we start by getting rid of Americans, I asked him, since they consume 35 per cent of the world's resources even though they are only 6 per cent of the world's people? The entire population of what used to be called the Third World uses up only the same quantity of the world's resources as the US.
Or should we perhaps begin with the Dutch? In Holland there are more people per square kilometre than anywhere else in the world, apart from odd little principalities such as Monaco, Gibraltar, or Vatican City, which has its own singular policy to birth control, requiring almost all its residents to be men.
There is more nonsense talked about population than almost any subject in international politics. That has been so since Thomas Malthus first predicted in 1798 that human reproduction would end in famine and catastrophe. Malthus failed to foresee the Agricultural Revolution which increased food production radically.
Today the world is still easily capable of producing enough to feed seven billion, and more. We will need to increase agricultural productivity by two-thirds by the time the population peaks at nine billion in 2050, but food production rose by five times that amount in the four decades to 2010.
The idea that there are too many poor people is the propaganda of a rich, Western, elite determined to preserve its privileged stranglehold on the world's resources. The truth is that changes to the climate, biodiversity, oceanic acidity and greenhouse-gases are all 20 times more our fault, measured in carbon emission tons, than that of poor people in Africa and Asia.
It is our industrial processes, SUVs, fertilised lawns, protein-based diets, and pet-keeping habits that are the real problem. A British cocker spaniel has a bigger carbon pawprint than the average human being in India. The average American consumes as much as 32 Kenyans. Yet population growth in the next two decades is mostly in countries which make the smallest contribution to greenhouse gases.
You could, anyway, fit seven billion people into Texas with a density no higher than that of New York. But it's not how many people that's the issue. It's who, and where they are.
The number of children a woman can expect to have is far more important than crude numbers. When the fertility rate rises, as it did in the UK in 1945, a generational wave surges through society. When that generation becomes old enough to work it means there are lots of economically active adults, smaller families, rising income, better standards of living, greater life expectancy, economic growth, increased demand and social change. Economists call it a "demographic dividend". Post-war Europe had one after 1945 and East Asia had one post-1980.
That may be the real story of the rise of China and India as economic super-powers. Previously this was put down to globalisation and high wages in developed countries. But it may well have been a demographic dividend. The emergence of America in the 1800s may have had the same cause, rather that the old explanation of increased global free trade. In China this rising population became sophisticated manufacturers; in India they developed software outsourcing.
All that explains why Malthus, and his latterday followers, have repeatedly got it so wrong. In 1968, the biologist Paul Ehrlich rekindled the Malthusian fire with his bestseller, The Population Bomb, which predicted the deaths of hundreds of millions in the 1970s. Around that time, President Lyndon Johnson, fearful that America could be overwhelmed by desperate masses, compelled recipients of US aid to adopt family planning. India set sterilisation quotas, with whole villages rounded up; eight million Indians were sterilised in 1975 alone. China's One Child Policy prevented 400 million births and saw millions more sterilised or aborted in the world's most aggressive population control initiative.
Individuals in poor countries need choice not control. Where life is uncertain, people want big families because there are so many jobs to do – fetching water from distant wells, collecting firewood, tending herds. Kids are the only life insurance available in your old age. When half your children will die before the age of five, it makes sense to have lots. Big families are a symptom of poverty not a cause.
History shows that a sustained fall in birth rates is always preceded by a significant fall in child death rates. Women in poor communities do not just need family planning they need full health services. They need rights to food, water, justice and fair wages alongside reproductive rights. Women's literacy programmes are what lower infant mortality and birth rates. That was obvious in India if you compared Kerala with the more impoverished northern states, as Amartya Sen showed. Development is the best contraceptive.
But the demographic dividend generation ages. When it retires it depends on a smaller generation coming behind to pay for its care. That has already happened in Japan, the oldest society the world has ever known. It is happening in the US and Europe, where the dependent young and old now nearly outnumber the working population. According to The Economist, China will be older than the US as early as 2020 and older than Europe by 2030. That will bring an abrupt end to its cheap-labour manufacturing. Its dependency ratio will rise from 38 to 64 by 2050, the sharpest rise in the world.
Within two decades, the burgeoning young, high-fertility population of Africa could become the fastest-growing continent in the global economy. Theirs will be the only part of the world to see its dependency ratios falling. Africans may then look to the old world and begin to wonder if it were not time that its useless and ineffective population were controlled, though that would mean "encouraging" euthanasia rather than birth control. It's a dodgy business, blaming the victims.