‘Sustainability’ the only answer to over-population

A planet-wide conflict that claimed as many lives as the first two world wars combined would hardly make any difference to the world’s exploding population, according to a study.

Population growth is so out of control that even stringent restrictions on childbirth, disastrous pandemics or a third world war would not make it manageable by the turn of the next century, the researchers claim.

Rather than reducing the number of people on the planet, cutting the consumption of natural resources and enhanced recycling would have a better chance of achieving effective sustainability gains in the next 85 years, they said. Prof Barry Brook, who co-led the study at the University of Adelaide, Australia, said: “We were surprised that a five-year WW3 scenario, mimicking the same proportion of people killed in the first and second world wars combined, barely registered a blip on the human population trajectory this century.”

The Second World War claimed between 50m and 85m military and civilian lives, according to different estimates, making it the most lethal conflict by absolute numbers of dead in human history. More than 37m people are thought to have died in the First World War.

The scientists used a computer model based on demographic data from the WHO and US Census Bureau to investigate different population reduction scenarios.

They found that under current conditions of fertility, mortality, and mother’s average age at first childbirth, global population was likely to grow from 7bn in 2013 to 10.4bn by 2100.

Climate change, war, reduced mortality and fertility, and increased maternal age altered this prediction only slightly. A devastating global pandemic that killed 2bn people was only projected to reduce population size to 8.4bn, while 6bn deaths brought it down to 5.1bn.

The findings are published in the journal Proceedings Of The National Academy Of Sciences.

Co-author Prof Corey Bradshaw, also from the University of Adelaide, said: “Global population has risen so fast over the past century that roughly 14% of all the human beings that have ever existed are still alive today. That’s a sobering statistic.

“This is considered unsustainable for a range of reasons, not least being able to feed everyone as well as the impact on the climate and environment.

“Even a worldwide one-child policy like China’s, implemented over the coming century, or catastrophic mortality events like global conflict or a disease pandemic, would still likely result in five to 10bn people by 2100.”

Nine different scenarios were constructed, ranging from “business as usual” population growth to highly unlikely disasters resulting in billions of deaths.

Prof Brook, now at the University of Tasmania, said: “Our work reveals that effective family planning and reproduction education worldwide have great potential to constrain the size of the human population and alleviate pressure on resource availability over the longer term.

“Our great-great-great-great grandchildren might ultimately benefit from such planning, but people alive today will not.”

Prof Bradshaw added: “The corollary of these findings is that society’s efforts towards sustainability would be directed more productively towards reducing our impact as much as possible through technological and social innovation.”