Opinion: To the power of 10

The UN predicts that the global population will grow to 10 billion people by 2100. Far from being a demo- graphic crisis, Danny Dorling believes that – if correct – this number could signify an age of improved sustainability for the environment and the global economy

In 2011, the UN predicted that there will be 10.1 billion of us by the year 2100: 10 billion by 2090, and then a further 100 million in 10 years. While these numbers might sound alarming to many, this would actually mean a future population growth rate of only 0.1 per cent a year by 2100, a rate last experienced worldwide for any prolonged period before 1492.

It is difficult to predict our final maximum number – a few years ago the UN demographers thought it would be 9.1 billion on that same 2100 date. Then they said 10.1 billion in 2011, and in June 2013 they upped that to 11 billion. Meanwhile, one article in the journal, Bioscience, in 2004, suggested that the best estimate for the future population of the planet is 7.7 billion; but that the lower and upper bounds of how many there could soon be were between 0.65 billion and 98 billion.

More of us are living in societies that are becoming stable enough that we do not need to have many children to safeguard ourselves in old age

But one thing experts are sure of is that soon our numbers will begin to fall. There has been a human worldwide population algae bloom and it is finally coming to an end. As the global human population acceleration began, Charles Darwin wrote that following a few ‘favourable seasons’, the rise in species number can be astonishing. We have had a few favourable seasons, lasting about six generations, and the rise has indeed been astonis-hing. We have increased from around a billion people when Darwin was a boy to nearer two billion a few decades after he died. We hit three, four, five, six and seven billion within 150 years but then our rate of growth began to dramat-ically slow, from 1971.

Across rich countries, for the first time, people plan to try to conceive children, often finding it harder to become pregnant than avoid pregnancy. However, this is not the only factor slowing birth rates down. More of us are living in societies that are becoming stable enough that we do not need to have many children to safeguard ourselves in old age. Worldwide, the average family has three children. Each of those children is expected to have two children, and world population growth will end.

Recent research suggests that population growth could easily slow down faster than expected. People tend to have fewer children during a recession, and we are discovering that there need be no more baby booms. Fertility rates are now incredibly low in several very large cities in Asia. We may even be over-estimating future population growth – we could easily never make it to 10 billion people.

That’s not to say that population growth doesn’t have its benefits. Modern capitalism and many of the advantages it has brought was nurtured and sustained by the 1851-1971 population explosion. Economic growth was driven by demographic expansion creating more customers. Future gene-rations are unlikely to live under the same economic system because customer numbers will not be continually growing. We can expect to see a transformation of capitalism as population growth comes to an end, which will in turn change our consumption habits. A more stable economy may well be a lower consumption economy as older consumers are less susceptible to advertising, and as business has to plan for declining needs.

Climate change influenced by over-consumption will continue to occur regardless of our numbers if future generations do not change their habits.

In an economically calmer and slower world climate change could more easily abate, even with a popu-lation of 10 billion. For example, people packed tightly into cities are forced to use public transport more and cars less.

The way things are going now, most of the northern polar region that is now white will soon be repainted in hues of dark blue as sea ice melts. Other areas will become green, where currently snow-covered tundra gives way, eventually, to boreal conifer forest. Our planet is about to change colour because of us, but not because of our numbers. A much smaller world population could pollute even more than the older, larger but more stable 10 billion, we will soon become.