and then when you're ready to launch use the code rll to get 10 percent off at checkout.

然後當你準備啟動時，使用代碼RLL在結賬時獲得10%的折扣。

Never before in all of human history has there existed as many people at one time as today.

在整個人類歷史上，從來沒有像今天這樣在同一時間存在這麼多的人。

The most recent population estimates conducted in October 2018 have concluded that 7.7 billion of us exist across the planet

2018年10月進行的最新人口估算得出結論，整個地球上存在著77億的我們

60 percent of us are living in Asia.Another 16 percent of us are living in Africa.

我們60%的人生活在亞洲.另外16%的人生活在非洲。

10 percent are living in Europe,while only 7.5 percent of us live in North America

10%的人生活在歐洲，而我們只有7.5%的人生活在北美。

And 5.5 percent of us live in South America

而我們有5.5%的人生活在南美。

But when you go back in time to 1800 and see that the world population was only 1 billion people back then,it begs the question as to why so many more people exist today than existed in the past.

但當你回到1800年，看到當時的世界人口只有10億，這就不禁要問，為什麼今天的人口比過去多了那麼多。

How many more people can we expect to have in the future, and what kind of problems might that bring along

我們可以預期未來還會有多少人，這可能會帶來什麼樣的問題？

To answer these questions,it's important to look back through history for some context.

要回答這些問題，重要的是回顧歷史，尋找一些背景。

The last time the world population shrunk was the period between 1200 and 1400;largely due to the Mongol conquest in Asia and the Black Death in Europe

上一次世界人口減少是在1200年到1400年之間；主要是由於蒙古人在亞洲的征服和歐洲的黑死病。

Which killed of up to half of that continent's population

導致該大陸一半的人口死亡

In 1340,the world population stood at around 450 million people.

1340年，世界人口約為4.5億人。

But by 1400 it had dwindled down to just 350 million

但到了1400年，它已經減少到只有3.5億人了

It took the entire world nearly 2 centuries to gain back its pre-1340 population.

整個世界用了近2個世紀的時間，才把1340年以前的人口找回來。

But from 1500 on,the population has been continously growing

但從1500年開始，人口一直在持續增長。

It was slow,at first.Humanity first reached half a billion people sometime in the 16th century.

起初，它是緩慢的，人類第一次達到5億人是在16世紀的某個時候。

And didn't achieve a full billion until 1804

而直到1804年才實現滿億的目標

It took us over 200,000 years of human history to reach 1 billion people being alive at the same time.

我們用了20多萬年的人類歷史，才達到10億人同時活著。

But the next billion would happen much more rapidly.

但下一個億會發生得更快。

2,000,000,000 people was achieved only 123 years later,in 1927.

在123年後的1927年，才實現了200萬人口的目標。

And then,it took only 33 more years to hit 3,000,000,000

然後，只用了33年時間就達到了300萬億的目標

And 14 years from there to hit 4 billion

而14年後達到40億

By 2024,the world population will likely hit 8 billion.

到2024年，世界人口將可能達到80億。

So clearly,based on this graph, something during the 19 and 20th centuries that caused our population to explode

很明顯，根據這張圖，19世紀和20世紀的一些事情導致了我們人口的爆炸性增長。

But if you look carefully you can actually notice three major population jumps over the span of the past few thousand years.

但如果你仔細觀察，其實可以發現在過去幾千年的時間裡，人口有三次大的跳躍。

This most recent one just happens to be the largest

最近的這個正好是最大的一個

Each of these jumps coincides with a major leap in technology.

每一次的跳躍，都恰好是技術上的一次重大飛躍。

The first,was the toolmaking revolution.

第一個，是工具製造革命。

Which allowed primitive humans to hunt more efficiently and give them greater access to higher calorie foods,like animal meat.

這使得原始人能夠更有效地狩獵，並使他們有更多的機會獲得更高熱量的食物，如動物肉。

An increase in the amount of high calorie food led to a gradual population boom for the species.

高熱量食物數量的增加，導致該物種的數量逐漸旺盛。

The second population jump happened during the time of the agricultural revolution,10 thousand years ago.

第二次人口跳躍發生在一萬年前的農業革命時期。

When humans first began to transition away from hunting and gathering and towards farming

當人類開始從狩獵和採集過渡到農業時

This even further increased the amount of food available,and therefore allowed for the development of cities and civilizations,which of course meant more people.

這甚至進一步增加了食物的數量，是以允許城市和文明的發展，這當然意味著更多的人。

The final,and most significant leap though,was the industrial revolution.

最後，也是最重要的一次飛躍，是工業革命。