is sitting on top of Greenland and Antarctica,

正坐在格陵蘭島和南極洲之上。

and each year, a little more of it melts into the ocean.

每年都會有更多的東西融進海里

Normally, it would take hundreds to thousands of years

正常情況下，需要幾百年到幾千年的時間。

for it all to melt away.

為這一切融化。

But what if something happened

但如果發生了什麼事呢

that caused a massive global melt overnight?

導致一夜之間全球大面積融化？

As we slept, sea levels would rise

當我們睡覺時，海平面會上升

by a whopping 66 meters.

以高達66米。

Coastal cities like New York, Shanghai, and London

紐約、上海、倫敦等沿海城市。

would drown in the apocalyptic mass flood,

會淹沒在世界末日的大洪水中。

forcing up to 40% of the world's population

迫使世界上多達40%的人口被迫離開。

out of their homes.

出他們的家。

While all this chaos ensues aboveground,

當這一切混亂髮生在地面上的時候。

something equally sinister is happening below.

下面還發生了同樣邪惡的事情。

All that rising salt water will infiltrate

所有上升的鹽水都會滲入地下。

groundwater reserves farther inland,

更遠的內陸地區的地下水儲備。

forcing its way into nearby freshwater aquifers.

迫使其進入附近的淡水含水層。

You know, the ones that supply our drinking water,

你知道，那些供應我們飲用水的人。

irrigation systems, and power-plant cooling systems?

灌溉系統和發電廠冷卻系統？

All those aquifers would be destroyed.

所有這些含水層都會被破壞。

Not good.

不太好

On top of that, the ice on Greenland and Antarctica

除此之外，格陵蘭島和南極洲的冰層也是如此

is made of fresh water, so when it melts,

是由淡水製成的，所以當它融化後。

that's about 69% of the world's freshwater supply

佔全球淡水供應量的69%左右

that's going straight into the oceans.

這是要直接進入海洋。

This will wreak havoc on our

這將會對我們的生活造成嚴重的破壞。

ocean currents and weather patterns.

洋流和天氣模式。

Take the Gulf Stream, for example.

以灣流為例。

It's a strong ocean current

這是個強大的洋流

that brings warm air to northern Europe

給北歐帶來了暖空氣

and relies on dense, salty water from the Arctic

並依靠來自北極的稠密鹹水為生

in order to function.

才能發揮作用。

But a flood of fresh water would dilute the current

但淡水的泛濫會沖淡這股水流

and could weaken or even stop it altogether.

並可能削弱甚至完全停止。

Without that warm air,

沒有了那股暖氣。

temperatures in northern Europe would plummet,

北歐的氣溫會驟然下降。

and that could spawn a mini ice age,

這可能會催生一個小冰河時代。

according to some experts.

據一些專家介紹。

That's not even the worst of it.

這還不是最糟糕的。

Take a look at what will happen

看看會發生什麼

when that last 1% of freshwater ice

當最後1%的淡水冰層

that's not part of Greenland or Antarctica thaws.

這不是格陵蘭島或南極洲融化的一部分。

Some of that 1% is sitting in glaciers farther inland.

這1%中的一部分是在更遠的內陸的冰川中。

The Himalayan glaciers specifically

特別是喜馬拉雅冰川

pose one of the largest threats

構成的最大威脅之一

because of what's trapped inside:

因為裡面藏著什麼。

toxic chemicals like dichlorodiphenyltrichloroethane,

二氯二苯三氯乙烷等有毒化學品。

or DDT.

或滴滴涕。

Scientists discovered that glaciers like this

科學家發現，像這樣的冰川

can store these chemicals for decades.

可以將這些化學品儲存幾十年。

But as they thaw, those glaciers release the chemicals

但當它們解凍時，這些冰川會釋放出化學物質

into rivers, lakes, and groundwater reserves,

進入河流、湖泊和地下水保護區。

poisoning each one as they go.

一邊走一邊給每個人下毒。

The rest of that 1% is hanging out underground,

剩下的那1%的人在地下閒逛。

mostly in the Arctic tundra,

多在北極凍土區。

as something called permafrost.

作為一種叫做永凍土的東西。

Permafrost is organic matter that's been

凍土是一種有機物，它是被破壞的。

frozen in the ground for two-plus years.

凍在地下兩年多。

Now, one of the most immediate problems

現在，最直接的問題之一是

with thawing permafrost would be mercury poisoning.

凍土解凍將導致汞中毒。

That's right: There are an estimated 15 million gallons

是的估計有1500萬加侖

of mercury stored up in the Arctic permafrost.

儲存在北極永久凍土中的汞。

That's almost equal to the amount of mercury

這幾乎等同於汞的數量。

everywhere else on Earth.

地球上的其他地方。

On top of that, the organic matter in permafrost

除此之外，永久凍土中的有機物

is a tasty meal for microorganisms.

是微生物的美味佳餚。

After they digest it all, they fart out

他們消化完之後，就會放屁了

two of the most potent greenhouse gases out there,

兩種最強的溫室氣體。

carbon dioxide and methane.

二氧化碳和甲烷。

Scientists estimate this could double

科學家們估計，這可能會增加一倍

the current levels of greenhouse gases in the atmosphere,

大氣中溫室氣體的當前水準；

and potentially cause global temperatures to rise

並可能導致全球氣溫上升

by 3.5 degrees Celsius compared to today.

與今天相比降低了3.5攝氏度。

That might not sound like much,

這可能聽起來不大。

but say goodbye to that mini European ice age,

但告別了那個小型歐洲冰河時代。

and even rivers and lakes around the world.

甚至世界各地的江河湖泊。

They'd evaporate from the higher temperatures

它們會因為溫度過高而蒸發掉

and cause mass droughts and desert-like climates.

並造成大規模乾旱和類似沙漠的氣候。

And all that extra water vapor in the atmosphere

大氣中所有多餘的水蒸氣。

would fuel more frequent and stronger

將助長更頻繁、更強烈的

storms, floods, and hurricanes.

風暴、洪水和颶風。

So all of that newly established coastline on the eastern US

所以，所有的新建立的海岸線 在美國東部的

would be one of the last places you'd want to live.

會是你最不想住的地方之一。

Instead, there would be mass migrations to Canada, Alaska,

反而會大量移民到加拿大、阿拉斯加。

the Arctic, and even what's left of the Antarctic.

北極，甚至是南極的剩餘部分。

And you're right, this is probably never going to happen.

你是對的，這可能永遠不會發生。

After all, there's enough ice right now

畢竟現在的冰塊已經夠多了。

to cover the entire continent of North America

覆蓋整個北美洲大陸

in a sheet a mile thick.

在一英里厚的薄片。

So the next time you hear about record-breaking heat

所以下次你聽到破紀錄的熱度時

or ultra-powerful hurricanes,

或超強颶風。

at least you know that it could be worse.

至少你知道，它可能會更糟。

But scientists estimate that if we don't take action

但科學家估計，如果我們不採取行動的話

and global temperatures increase by just 1 degree Celsius,

而全球氣溫僅上升1攝氏度。

the effects of climate change we already see today

我們今天已經看到的氣候變化的影響

will be irreversible.

將是不可逆轉的。

So yes, it could be worse,

所以，是的，可能會更糟。

and it will be if we're not careful.

如果我們不小心的話，就會這樣。