Elon Musk steps onto the stage at a conference in Italy. In three decades, the world's population will be "one tenth of its current size", he says, while the birth rate, "is maybe half the replacement rateThe rate of births needed for babies to replace their parents. ".

The fertility rate is the average number of babies born to each woman. In England and Wales that number has reached 1.44 - the lowest rate since 1938. For a population to remain the same, the fertility rate needs 2.1 babies per woman.

Economists disagree about whether this is a problem. Some argue that, if the population declines, governments will struggle to pay for basic services.

One solution is immigration, which keeps the population growing, but can cause social unrestA state of general dissatisfaction expressed in unconventional and sometimes violent ways..

According to UN projectionsEstimates or forecasts of future situations., the global population is likely to peak at 10.3 billion in the next 60 years. Population growth in Africa, Central Asia and Southern Asia will offsetTo balance one effect against an opposing effect. any decline in Europe and America.

Even if these figures are wrong, a drop in the global population might have long-term benefits. By reducing the demand for food and energy, it will slow the pace of global warming and environmental destruction.

Is Planet Earth running out of humans?

Yes! Fertility rates are falling across America, Europe and Eastern Asia. Musk is right to warn about the coming crisis.

No! Globally, the population is growing and expected to peak in the second half of the century.