Never before in history, have there been so many people on Earth as right now.
Our numbers have skyrocketed,
从1800年的10亿 到1940年的23亿 1970年的37亿到2016年的74亿
from 1 billion in 1800, to 2.3 billion in 1940, 3.7 billion in 1970, and 7.4 billion in 2016.
The world population increased fourfold in the last century, so what can we expect for the next century?
And what does population growth mean for our future?
Will there be mass-migration?
Overcrowded slums and megacities covering continents?
Diseases and pollution?
会出现因为能源 水 和食物所造成的混乱与暴力吗？
Chaos and violence over energy, water, and food?
And a human species focused only on sustaining itself?
Will population growth destroy our way of life?
Or is this prophecy just ungrounded panic?
In the 1960s population growth reached an unprecedented rate.
Which lead to apocalyptic prophecies.
The poor would pro-create endlessly and overrun the developed world.
The legend of overpopulation was born.
But it turns out high birth rates and the population explosion are not permanent features of some cultures or countries,
But rather a part of a four step process the whole world is going through,
The demographic transition.
Most developed countries have already made the transition, while other countries are doing it right now.
Let’s go back to the 18th century, when the entire world, including Europe,
was in the first stage of the demographic transition.
By today’s standards, Europe was worse off than a developing region,
因为其糟糕的卫生环境 短缺的食物 和简陋的医疗条件
suffering from poor sanitation, poor diets, and poor medicine.
出生率很高 但死亡率也不低 所以人口基本上不怎么增长
A lot of people were born, but lots of them died just as fast, so the population hardly grew.
Women had between 4 and 6 children, but only 2 of them would reach adulthood.
Then the industrial revolution happened in the UK
and bought the greatest change in human living conditions since the agricultural revolution.
People went from being peasants to workers.
Manufactured goods were mass produced and became widely available.
科学繁荣发展 与其一同发展的还有先进的交通 通讯 以及医疗
The sciences flourished and advanced transportation, communication, and medicine.
The role of women in society shifted and created the conditions for their emancipation.
Slowly this economic progress not only formed a middle class, .
but also raised standards of living and health care for the poor working population
The second transition stage started.
更好的食物供给 卫生 和医疗 意味着死亡率的降低 尤其是孩童死亡率的降低
Better food supplies, hygiene and medicine, meant people stopped dying all the time, especially so, at a very young age.
The result was a population explosion.
Doubling the UK’s population between 1750 and 1850.
The main reasons families used to have lots of children was that only a few of them were likely to survive.
Now that had changed, so the third stage of transition was set in motion.
Fewer babies were conceived, and population growth slowed down.
最终达到一个平衡 死亡人数减少 出生人数也减少 使得出生率和死亡率保持平衡
Eventually a balance emerged, fewer people were dying and fewer children were born, so the death rate and birth rate became stable.
Britain had reached the fourth stage of the demographic transition.
This didn’t only happen in the UK, more and more countries went through the four stages.
First, many births and many deaths due to bad living conditions.
Second, better living conditions leading to fewer deaths and a population explosion.
再后来 低死亡率导致低出生率 人口不再增长
Third, fewer deaths resulting in fewer births, and population growth came to an end.
But if birth rates have dropped so much, why is the population still growing so fast?
Well, the children born in the population explosion of the 70s and 80s are having kids themselves now.
Leading to a noticeable spike in overall population.
But they are having far fewer children on average than their parents.
The average today is 2.5, it was 5, 40 years ago.
特别是当这一代人老去 生育率继续下降 人口增长率也将持续放缓
So as this generation gets older, and fertility declines further, the rate of population growth will keep on slowing.
This is true for every country.
In the west, we tend to overlook progress in other regions of the world.
But actually most of the world’s countries have made it to the fourth stage.
1971年 孟加拉国的女性平均有七个孩子 但是其中有25%的小孩在五岁前就死亡了
Just look at Bangladesh. In 1971, the average woman had 7 kids, but 25% of them would die before the age of 5.
2015年 死亡率下降到3.8% 但女性平均只有2.2个小孩
In 2015, the mortality rate was down to 3.8% and women had only 2.2 kids on average.
这是规律 没有例外 我们并不特殊 只是先行一步而已
This is the rule, not an exception, we’re not special, we just had a head start.
It took developed countries about 80 years to reduce fertility from more than 6 children, to less than 3.
其他国家迎头赶上 马来西亚和南非仅用了34年的时间 孟加拉国只用了20年的时间
Others are catching up fast. Malaysia and South Africa did it in only 34 years; Bangladesh took just 20.
Iran managed it in 10 years.
所有这些在努力追赶的国家并不需从零开始 他们获得的支持越大 也就能越快赶上我们
All these countries that are catching up didn’t have to start from scratch and the more support they get, the faster they catch up.
This is why programs that help lower child mortality or help poor nations develop, are so important,
No matter what your motivation is,
whether you dream of a world where all people live in freedom and wealth,
or you just want fewer refugees coming into your country,
一个简单的真理就是 如果在世界的另一边的人们可以有一个很好的生活 你的生活也会因此受益
The simple truth is, that it’s beneficial to you personally if people on the other side of the globe can live a good life.
And we are getting there, the percentage of people living in extreme poverty has never been as low as today.
So the future of global population growth is actually not an apocalyptic prophecy at all, it’s a promise!
Population growth will come to an end.
The UN forecasts that the 12th billionth human will never be born at all.
And as the development level of the world rises, the number of people with a higher education will increase tenfold.
Countries who used to be in need, will help advanced development instead.
More people is going to mean more people able to advance our species.
这个视频由Max Roser和ourworldindata合作完成 在这里他通过研究和数据可视化 探索了人类的进步
This video was a collaboration with Max Roser and ourworldindata, where he explores the progress of humanity through research and data visualisation.
Make sure to check it out!
In 2016 we were able to make more and better content than ever before, because of your support on Patreon.com.
Thank you so much and we will be back in The Year 12,017.