What would happen if everyone in the world was suddenly a vegetarian?

如果世界上的每個人都突然變成素食者，會發生什麼事呢？

What effect would it have on our lives and the planet?

對我們的生活和地球又會有什麼影響呢？

Before we begin, full disclosure: None of us at AsapSCIENCE are vegetarians.

在我們開始之前，要事先宣告：我們 AsapSCIENCE 團隊的所有人都不吃素。

And the worldwide rate of vegetarianism is fairly low, ranging from about 4-5% in the US and Canada to a little over 30% in India.

而且世界上的素食者比例相當低，範圍從美國和加拿大的約占 4─5% 到印度的約略超過 30% 。

As a result, there are currently about 20 billion chickens, 1.5 billion cows, over a billion sheep and nearly a billion pigs in the world.

因此，世界上大約有 200 億隻雞、15 億頭牛，超過 10 億隻羊以及將近 10 億頭豬。

Without any meat-eating humans to provide a market, whole herds of domestic animals would disappear.

如果毫無任何食肉人口來創造肉類市場，所有的家畜群將會消失。

And this would free up vast quantities of land.

而且這樣的話也會空出大量土地。

About 33 million square kilometres of land are used for pasture - an area about the size of Africa.

大約三千三百萬平方公尺的土地是被用來放牧的 ─ 這相當於一個非洲的大小。

And that’s not even counting the land used to grow crops exclusively for animal feed.

而且我們還沒計算種植畜牧飼料用地的面積呢。

Some of it would be needed for the increased amount of vegetable crops, but much of the land currently used as pasture is actually too dry to grow crops.

某些畜牧飼料用地可能需要被做為生產日益增加的蔬菜作物，但目前大部分用來做為牧地的土地事實上對作物來說太乾了，使作物無法生長。

Without humans adding artificial nutrients, this land could turn to desert,

當人們不再加入人工肥料，這片土地可能會變為沙漠，

but if properly managed, it’s possible that some farmland would return to its natural state of grassland or forests, which could help counteract global climate change.

不過如果妥善的管理，有些農田也是有可能恢復到以往的自然狀態的，像是草原或森林等等，這樣的原始林地能幫助緩和全球氣候的變遷。

After all, the loss of CO2-absorbing trees cleared for agriculture is a major reason why global levels of CO2 are going up.

畢竟為了農業而清除掉能吸收二氧化碳的樹，才是全球 CO2 含量升高的主要原因。

Cows and other grazers also affect our climate through large amounts of methane production, which has 25 times more potential planet-warming power than CO2.

牛和其他草食動物製造的大量甲浣也影響著我們的氣候，這些甲浣造成的潛在全球暖化力是二氧化碳的 25 倍。

Combined with the loss of forests and other effects, livestock production is responsible for about 15% of global greenhouse gas emissions,

結合森林的損失及其它影響，全球溫室氣體排放量的 15% 是家畜需要負責的，及其它影響，全球溫室氣體排放量的 15% 是家畜需要負責的，

which is more than all the world’s planes, trains and automobiles put together.

這比全世界的飛機，火車和汽車的溫室氣體總排放量還多。

In fact, many scientists believe that reducing meat consumption may be one of the best strategies for managing climate change.

事實上，許多科學家都相信減少肉類攝取或許是最能管理氣候變遷的策略之一。

A vegetarian diet would also greatly reduce water consumption; around 70% of global freshwater consumption is used in agriculture.

素的飲食也會大大的減少水的消耗量；全球有 70% 的淡水被消耗在農業。

It takes 15,000 litres to make a kilogram of beef, 6,000 L for pork and 4,000 L for chicken - Compare this with 1,600 L for cereal crops, 900 L for fruit and 300 L for garden vegetables.

其中，每製造一公斤的牛肉，就要用掉 15000 公升的水；每製造一公斤的豬肉，就要用掉 6000 公升的水，而製造相同重量的雞肉，也要耗費 4000 公升的水─和製造一公斤的作物相較，穀類只要 1600 公升的水，水果只要 900 公升，而菜園裡的菜也只需 300 公升。

Of course, a kilogram of meat packs many more calories than the equivalent weight of fruit,

當然，一公斤的肉類所含的卡路里是遠高於同等重量的水果所含的，

but even if you compare the ratio of water per calorie of available food energy,

但即使你比較可用食物熱量中每單位卡路里所消耗的水量，

beef is still 5 times more water intensive than fruit, 7 times more than veggies and 20 times more than cereal.

製造牛肉仍比製造水果增加了 5 倍的水量比製造蔬菜多了 7 倍的水量，以及比製造穀物多了 20 倍的水量 。

So are there any downsides to a vegetarian diet?

這樣的話，素食飲食有任何的缺點嗎？

Well, we’d be left without a cheap source for many byproducts of livestock, like leather from animal hides, or animal fats which are used in cosmetics, candles and detergents.

嗯，如果大家都吃素的話我們就得活在一個沒有便宜牲畜副產品資源的世界，像是由動物皮製成的皮革，還有用來做為化妝品，蠟燭和清潔劑原料的動物脂肪。

And while vegetable based alternatives do exist, their production would need to increase, meaning more land dedicated to growing crops and less restored to its natural state.

當這些轉變成蔬菜性替代品，這些替代產品的製造量就必須增加，意味著更多土地用於種植作物，而更少土地能恢復到它自然的狀態。

A more complicated fact is that raising and processing animals is a full-time job for more than 1 billion people - most of whom are small-scale farmers in the developing world.

更複雜的一個因素是因為全球超過 10 億人口是以飼養動物和加工動物產品做為全職 ─ 他們大部分都是發展中世界的小規模農場主。

While some may be able to move to producing milk or eggs, or even growing vegetable crops, many would be faced with their way of life becoming obsolete.

雖然他們有些人能夠轉為生產牛奶或雞蛋，或甚至是種植蔬菜作物，但許多人可能會面臨失業的情況。

Of course, any increase in vegetarianism is likely to be a gradual process rather than a sudden cut-off.

當然，素食主義的增加更像是漸進的過程，而非突然的變化。

And, surprisingly, the trends are actually in the opposite direction.

令人驚訝的是，事實上目前的趨勢是相反的。

In places like India and China, people are becoming wealthier, and as a result, consuming more meat which effectively cancels out the declines we see in other countries.

在像印度或中國這樣的地方，人們越來越有錢，因此他們也攝取越來越多肉類，這情形有效抵消了我們在其他國家看到的食肉比例下降的情況。

So, we actually tried to go vegetarian for 21 days straight as an experiment in our new AsapTHOUGHT episode.

所以，我們在新的 AsapTHOUGHT 的一集中嘗試實驗吃素 21 天

Check out the video if you want to see how it went, what we learned in the process and how we felt about it both mentally and physically!

如果你想知道我們如何實行，我們在過程中學到什麼，還有我們的感覺是什麼的話，就看看這個影片吧！我們的感覺是什麼的話，就看看這個影片吧！

And subscribe for more weekly science videos!

也要記得訂閱我們來收看每周的科學影片喔！