Ocean currents have a direct influence on our lives.

洋流對我們的生命有直接的影響

They determine our weather, our climate, and much more.

它們決定了我們的天氣、氣候等等

The ocean currents and wind systems

洋流以及風的系統

transport heat from the equator to the poles

將赤道的炎熱傳送到極地

and operate like a large engine for the global climate.

它像引擎般地操控著全球的氣候

In the oceans, there are numerous currents.

海洋中有眾多的洋流

The so-called ocean conveyor belt is very important for our climate.

這所謂的洋流對於我們的氣候是相當重要的

This term describes a combination of currents

這個語詞說明了洋流的組成

that result in four of the five global oceans exchanging water with each other.

就是海水會與其他海洋的水交換

They form a worldwide circulation system.

它們形成了一個互相聯繫的系統

The conveyor belt is also called the thermohaline circulation,

洋流也叫做「大洋熱鹽環流」

with “thermo” referring to the temperature,

「Thermo」指的是熱度

and “haline” to the salt content of the water.

「Haline」指的是海水中鹽的含量

Both determine the density of the water.

這兩者決定了海水的密度

While the masses of water may be moved in part by wind,

同時水的質量可以部分的由風移動

primarily the different densities of the global oceans are

主要是由這些海洋

responsible for their movement.

來負責自己的運動

Warm water has a lower density and rises while cold water sinks.

密度低的溫暖海水會上升而主要的寒冷海水則會下沉

The water’s density also increases with a higher salt content.

海水的密度同時也增加了鹽分的含量

At the equator the heat from the sun is especially strong,

受到太陽直射的赤道會特別的熱

resulting in a lot of evaporation and thus a rise in the water’s salt content.

造成海水蒸發進而使海水鹽分的密度增加

That is where the Gulf Stream begins.

這是墨西哥灣洋流一切的開始

The Gulf Stream is very important for the European climate.

墨西哥灣洋流對歐洲的氣候影響是非常的重要

Its length of 10,000 km makes it one of the largest and fastest currents on Earth,

它的長度超過一萬公里 是目前世界上最長且流速最快的洋流

and it’s very warm.

且它非常溫暖

At roughly 2 m/s it brings up to 100,000,000 m³ of water per second

大致上2公尺每秒的流速 它最多可帶來每秒一億立方公尺的海水

towards Europe.

朝歐洲前進

A constantly blowing wind, the southeast trade wind,

從東南方不斷吹來的信風

drives warm surface water to the northwest, into the

推動溫暖的海水表面到西北方並到達

Gulf of Mexico, where it heats up to 30 °C.

墨西哥灣 這裡的最高溫度可達30度

The turning of the Earth and the west winds then direct

地球的自轉及西風的影響下 洋流直接到達

the Gulf Stream towards Europe and split it up.

墨西哥灣並且往歐洲大陸分岔

One part flows south, another east to the Canary Current,

一部份的洋流流向南方 另一部份則向西流至加那利洋流

and a third part flows north where it releases a lot of heat

而還有另一部份的洋流流向北方並釋放出大量的熱

into the atmosphere as the North Atlantic Current.

並進入到北大西洋洋流

The water becomes colder there.

海水在這變得更涼了

Its salt content and density rise on the account of evaporation

海水鹽分的密度增加

and it drops down between Greenland, Norway, and Iceland.

且海面在格陵蘭 挪威和冰島間下降

There we also find the largest waterfall on Earth.

在這我們也可以找到世界上最大的瀑布

The so-called Chimneys, roughly 15-km-wide pillars with water falling up to 4,000 m.

瀑布Chimneys(未尋得適當中文音譯)大約寬15公里 水從4000公尺處往下流

17,000,000 m³ of water per second, or roughly 15 times more water than

每秒流下來的水為1700萬立方公尺 它流15次的水就比

is carried by all the rivers in the world.

地球上所有河流的水加總起來的還多

This creates a strong maelstrom, which constantly pulls in new water

這個瀑布創造了一個巨大的漩渦， 對海水形成吸力

and is the reason that the Gulf Stream moves towards Europe.

也就是讓墨西哥灣暖流向歐洲前進的動力

Countless species use the Gulf Stream as a means of transport on their trips

不計其數的生物藉由墨西哥灣暖流踏上他們的旅途

from the Caribbean to northern areas.

自加勒比海到北方海域

But it doesn’t just bring us animals;

但墨西哥灣暖流不僅為人們帶來許多生物

an enormous quantity of warm air also comes with it.

也帶來了巨量的溫暖空氣

In order to produce the same heat that it brings to the shores of Europe,

若要人為製造墨西哥灣暖流替歐洲海岸帶來的溫暖空氣

we would need 1,000,000 nuclear power plants.

需要一百萬座核能發電廠

That’s why we also call the Gulf Stream a heat pump.

這就是為什麼我們也稱墨西哥灣暖流作「熱泵」

Without it, the temperature would be significantly colder here,

沒有了它，歐洲的溫度將會下降

at least five to ten degrees.

至少５～１０度

Instead of lush fields, we would have long winters and sparse ice-covered

取代蓊鬱農場的， 將會是長長的冬天與散布歐洲四處的冰雪

landscapes in Europe.

取代蓊鬱農場的， 將會是長長的冬天與散布歐洲四處的冰雪

In the last few years, scientists and pundits in the media have repeatedly

在最近幾年， 科學家及有力人士已經在媒體上不斷地傳達

expressed the fear that the Gulf Stream could come to a standstill

因為氣候變遷墨西哥灣暖流可能因此中斷

due to climate change.

因為極地冰帽融化，格陵蘭附近海水的鹽分會下降， 同時造成海水密度下降

Because if the polar caps actually melt, the salt content in the water

因為極地冰帽融化，格陵蘭附近海水的鹽分會下降， 同時造成海水密度下降

off Greenland would fall, as would its density.

北大西洋漂流將因密度不足不再下沉

The North Atlantic Current would no longer be heavy enough,

北大西洋漂流將因密度不足不再下沉

and so it woundn’t sink as usual.

最糟的情況下， 這會使得墨西哥灣暖流的熱流系統就此停滯

In the worst case, that would bring the Gulf Stream, our heat pump, to a stop.

部分氣候學者則認為氣候變遷會自動修正這個現象

Some climate experts also assume that climate change could

部分氣候學者則認為氣候變遷會自動修正這個現象

compensate for this effect.

綜觀過去數百萬年的地球氣候發展

We know that it can be normal for the climate to change

我們都知道，地球會有正常的氣候變遷循環

by looking at the development of the Earth over the last few million years.

會有冰河時期及溫暖時期

There are ice ages and warm periods.

在上一次冰河時期，大量的融化淡水癱瘓了

In the last ice age, a gigantic flood of melting water crippled

北大西洋漂流的熱交換機制， 造成整個北半球壟罩在冰雪中

the heat-bringing North Atlantic Current, covering the northern hemisphere in ice.

科學家們 對於氣候變遷對大洋輸送帶的衝擊有許多不同的觀點

Scientists have different views on the impact that climate change will have

但有一點是清楚明顯的

on the global ocean conveyor belt, but one thing is clear:

當出現氣候變遷時，自上次冰河時期後一直保持穩定的

when the climate changes, then the complex system of ocean currents and winds,

海洋洋流及行星風系的系統

which has remained fairly stable since the last ice age,

將出現我們無法理解及預期的改變

will change in ways that we don’t yet understand.

字幕由GrayHS提供

Subtitles by the Amara.org community