Global population expected to peak at 9.7bn, then fall

THE world’s population is expected to peak at around 9.7billion in 2064 before falling back by almost a billion by the start of the next century, according to a study published today in The Lancet.

The report’s projected global population of 8.8billion in 2100 is around two billion lower than some previous estimates, and contrasts with the UN’S consistent projections of continued global growth. It represents a huge challenge to world leaders to rethink policies to cope with changing demographics and their consequences.

Scientists cite the key factors in generating widespread, sustained declines in fertility are improvements in access to modern contraception and in the education of girls and women.

All but seven of 195 countries surveyed are predicted to have falling fertility rates by 2100, according to estimates at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s school of medicine. The over-80s will outnumber under-fives by two to one, say researchers. Immigration will be key to the health of most economies.

It also predicts big shifts in global power, with Africa increasingly important. Nigeria will join the US, China and India as the world’s leading economic powerhouses, the report suggests.

Christopher Murray, the IHME director who led the project, said: “This study provides governments of all countries with an opportunity to start rethinking their policies on migration, workforces and economic development to address the challenges by demographic change.”

Prof Stein Emil Vollset, of the IHME, said: “Our findings suggest that the decline in the numbers of working-age adults alone will reduce GDP growth rates that could result in major shifts in global economic power by the century’s end.”

Even in Niger, where the fertility rate was the highest in the world in 2017 – with women having an average of seven children – the rate is projected to decline to around 1.8 by 2100. That compares with the 2.1 figure to sustain population. More than 20 countries are expected to see their populations shrink by more than half, including Italy, Spain, Japan and Thailand.

China is set to replace the US as the largest economy in 2035 but America is forecast to, once again, become the largest economy in 2098 – bolstered by immigration, scientists said.

Richard Horton, editor-in-chief of The Lancet, said: “The 21st century will see a revolution in the story of our human civilisation.”