The World’s Population May Peak in Your Lifetime. What Happens Next?
The global human population has been climbing for the past two centuries. But what is normal for all of us alive today — growing up while the world is growing rapidly — may be a blip in human history.
A baby born this year will be 60 in the 2080s, when demographers at the U.N. expect the size of humanity to peak. The Wittgenstein Center for Demography and Global Human Capital in Vienna places the peak in the 2070s.
The Institute for Health Metrics and Evaluation at the University of Washington puts it in the 2060s. All of the predictions agree on one thing: We peak soon.
And then we shrink. Humanity will not reach a plateau and then stabilize.
It will begin an unprecedented decline.
Because most demographers look ahead only to 2100, there is no consensus on exactly how quickly populations will fall after that.
Over the past 100 years, the global population quadrupled, from two billion to eight billion. As long as life continues as it has — with people choosing smaller family sizes, as is now common in most of the world — then in the 22nd or 23rd century, our decline could be just as steep as our rise.
Most people now live in countries where two or fewer children are born for every two adults. If all people in the United States today lived through their reproductive years and had babies at an average pace, then it would add up to about 1.66 births per woman.
In Europe, that number is 1.5; in East Asia, 1.2; in Latin America, 1.9. Any worldwide average of fewer than two children per two adults means our population shrinks and in the long run each new generation is smaller than the one before.
If the world’s fertility rate were the same as in the United States today, then the global population would fall from a peak of around 10 billion to less than two billion about 300 years later, over perhaps 10 generations.
And if family sizes remained small, we would continue declining.
blip
- 일시적인 상황 변화/문제, 깜빡 신호
- a bright dot on the screen of an electronic device
demographers : 인구통계학자
Demography : 인구변동, 인구 통계학
Humanity : 인류, 인간, 인간성
quadrupled : 4배가 되다, 4배의
steep : 가파른, 급겨간, 비탈진, 너무 비싼
fertility : 비옥함, 생식력