clouds cover about 70% of the planet at any given moment.

雲層在任何時候都覆蓋了地球的70%左右。

But what if, in the next minute,

但如果，在下一分鐘。

poof, they all disappeared?

噗，他們都消失了？

That instant might shock onlooking astronauts

那一瞬間，可能會驚動旁觀的太空人們

on the space station.

在空間站上。

But someone who is, say, hiking in the desert

但是有人，比如說，在沙漠中徒步旅行的人

wouldn't know right away that things on Earth

不知天高地厚

were about to get really bad.

變得非常糟糕。

Within a few days, though,

不過幾天之內，。

the first warning sign would show up: humidity.

第一個警告信號會出現：溼度。

It'll be even worse if you live by the coast.

如果你住在海邊，情況會更糟糕。

Normally, the sun's heat evaporates water,

正常情況下，太陽的熱量會蒸發掉水。

mostly from the ocean,

主要來自海洋。

and that water vapor is condensed into clouds.

而水蒸氣是凝結成雲的。

But if clouds are cut out of the Earth's water cycle,

但如果將雲從地球的水循環中剔除。

that water just hangs around in the air,

水只是掛在空氣中。

creating close to 100% humidity.

創造接近100%的溼度。

If you were to get on a flight,

如果你要上飛機。

you might experience more turbulence than usual.

你可能會經歷比平時更多的湍流。

Without the protective cover of clouds

沒有云的保護罩

to bounce sunlight into space,

將陽光反射到太空中。

the sun will heat the Earth more,

太陽會使地球更熱。

creating more rising, uneven hot air.

造成更多的上升，不均勻的熱空氣。

But a bad flight may be the least of our worries,

但飛行不順可能是我們最不擔心的。

because there'll be no more rain

因為不會再有雨了

or snow or even a light mist,

或雪，甚至是輕霧。

and that means there won't be any way

這意味著沒有任何辦法。

to replenish the water sources we drink from,

以補充我們飲用的水源。

like lakes, streams, rivers, springs, and aquifers.

如湖泊、溪流、河流、泉水和含水層。

So once last winter's snow melts,

所以，去年冬天的雪一旦融化。

we're stuck with whatever water we have on hand.

我們只能用我們手頭的任何水。

And the clock is ticking.

而時間在流逝。

If the world were to keep up

如果全世界都能跟上

its current water-consumption rate,

其目前的耗水率；

we would drain all of the freshwater lakes and rivers

我們會把所有的淡水湖泊和河流的水抽乾

in about 23 years.

23年左右的時間。

So to conserve our freshwater supply,

所以為了節約我們的淡水供應。

humanity will have to be strategic.

人類將不得不採取戰略。

Today, the average American uses

今天，美國人平均使用

about 80 to 100 gallons of water every day.

每天約80至100加侖的水。

But saving ourselves is going to take more

但拯救我們自己需要更多

than just skipping long showers and laundry.

不僅僅是跳過長時間的淋浴和洗衣服。

The water we use in our home and public places

我們在家庭和公共場所使用的水。

accounts for only 21% of our water usage.

只佔我們用水量的21%。

The two biggest demands are actually

其實最大的兩個要求是

thermoelectric power to generate electricity

熱力發電

and irrigation for farms.

和農場的灌溉。

Not only do power plants use tons of water,

電廠不僅要用大量的水。

ones that run on nuclear fuel could spell disaster

以核燃料為動力的，可能會帶來災難。

if their water-cooling towers run dry.

如果他們的水冷塔乾涸。

The 2011 Fukushima nuclear disaster, for example,

比如2011年的福島核災難。

was set off when an earthquake knocked out power

因地震斷電而被引爆。

to its water-cooling pumps.

到其水冷泵。

And farms are going to need even more water

而農場將需要更多的水。

without the help of a good rain.

沒有好雨的幫助。

This permanent drought would kill

這種永久性的乾旱會使人死亡

tons of wild vegetation and animals as the land dries up.

噸野生植被和動物，因為土地乾涸。

Within a few years,

幾年內。

eroding soil may kick up giant dust storms

侵蝕土壤可能引發巨大的沙塵暴。

like the Dust Bowl in the 1930s.

就像上世紀30年代的 "塵暴 "一樣。

Meanwhile, Earth's climate will be going haywire

同時，地球的氣候也會變得混亂不堪

without clouds.

無雲。

It's hard to say when this will all happen

很難說什麼時候會發生這一切。

without some very expensive climate modeling,

沒有一些非常昂貴的氣候模型。

but cloud expert Chris Fairall

但云計算專家Chris Fairall

did offer some quick back-of-the-envelope calculations.

確實提供了一些快速的包絡計算。

Without clouds, average surface temperatures

如果沒有云，平均地表溫度

would rise by as much as 22 degrees Celsius.

會上升22攝氏度之多。

This extreme temperature spike

這種極端的溫度高峰

would not only destroy the habitats of most flora and fauna,

不僅會破壞大多數動植物的棲息地。

killing off whatever survived the drought,

殺死任何倖存的乾旱。

it would also melt the polar ice caps

也會使極地冰蓋融化。

and cause massive flooding of coastal cities.

並造成沿海城市大面積洪澇災害。

You might end up being part of the 40% of the world

你可能會成為世界上40%的人中的一員。

that would be forced inland,

會被逼到內陸的。

and your new home might soon be in an endless desert

而你的新家可能很快就會在一望無際的沙漠中了

as seawater starts seeping into

由於海水開始滲入

our fresh and precious groundwater.

我們的新鮮和寶貴的地下水。

Sounds alarming, but there are some silver linings

聽起來很嚇人，但也有一線生機。

to a world without clouds.

到一個沒有云的世界。

No more devastating hurricanes and tornadoes,

不再有毀滅性的颶風和龍捲風。

or delayed flights because of stormy weather,

或因暴風雨天氣導致班機延誤。

or cloudy skies to ruin your stargazing.

或陰天毀了你的觀星之旅。

As the water supply dwindles,

隨著供水量的減少。

we'll have to make some hard choices,

我們將不得不做出一些艱難的選擇。

but, hey, humans are creative.

但是，嘿，人類是有創造力的。

We could invent ways to desalinate ocean water

我們可以發明海水淡化的方法。

or collect all that water vapor from the air.

或將空氣中的水蒸氣全部收集起來。

And the sooner we do it, the better,

而且我們越早做越好。

because in reality, we're already losing clouds.

因為在現實中，我們已經失去了雲。

Unprecedented levels of CO2

前所未有的二氧化碳水準

and the warming oceans and atmosphere

以及海洋和大氣變暖

are all causing clouds to thin out.

都是導致雲層變薄。

So despite the silver linings,

所以，儘管銀裝素裹。

it might be best to reduce our greenhouse gas emissions

最好是減少我們的溫室氣體排放。

and try to avoid this scary new world entirely.

並儘量完全避開這個可怕的新世界。