Eight billion. It’s a
number too big to imagine but think of it this way: In the time it takes
you to read this paragraph, the world’s population grew by around 20
people.
While the Earth’s population is growing quickly, the
growth rate is starting to slow down. Eventually, it will start falling
and our societies will shrink.
Humanity is changing day by day in ways we can’t perceive over short
periods, but in ways that will reshape our world over the coming
century.
We’ve come a long way, fast
Homo sapiens have roamed the Earth for roughly 300,000 years, give or take (no one left a diary back then).
We evolved to have big brains and long legs, but our population grew relatively slowly at first.
There
were perhaps 230 million of us on Earth at around the time of
Cleopatra’s death, as the ancient Egyptian civilisation came to an end.
The
population had more than doubled by the Renaissance in 1500 and doubled
again by 1805 when the ancient Egyptian civilisation was being
rediscovered with the help of the Rosetta Stone.
These are all
pretty rough estimates — we didn’t have comprehensive censuses in the
Middle Ages – but the human population has been on a slow burn, until
recent centuries, when it has boomed.
The 2 billion mark was reached just before the Great Depression in
1925, and it took just 35 years from there to get to the third billion.
Since then, the population has been rising by another billion every 10 to 15 years.
Where are we going?
The world is likely to have a couple more billion mouths to feed in just a few decades.
The UN’s latest projections, released earlier this year, suggest the world will house about 9.7 billion humans in 2050.
“Demographic
projections are highly accurate, and it has to do with the fact that
most of the people who will be alive in 30 years have already been
born,” the UN’s population division director, John Willmoth, says.
“But when you start getting 70, 80 years down the road, there’s much more uncertainty.”
Under its most likely scenario, the UN projects the world population will reach about 10.4 billion in the 2080s.
From there, it’s set to plateau for a couple of decades, before falling around the turn of the 22nd century.
But the range of reasonable possibilities in 2100 is considerably wider, between 8.9 and 12.4 billion.
