Great Barrier Reef.

的命危急訊。

Two years later, Outside magazine published this ― it’s...

兩年後，《外部雜誌》發行了這篇文章

another obituary for the reef.

另一個大堡礁的訃聞

And more recently, we got this news:

最近，我們看到這篇新聞

BBC News: And also this hour, the Great Barrier Reef is at a terminal stage.

BBC News:在此時此刻，大堡礁處於生命垂危的狀態

Have we really killed the Great Barrier Reef?

我們真的殺了大堡礁嗎?

The answer is no… but we sure are trying.

答案為非，但能確定我們有企圖

It’d be hard to call the time of death for

現在很難宣判大堡礁的死

the Great Barrier Reef because it’s actually some 3,000 reefs

它總共有3000個獨立礁石

spread over an area the size of Italy.

蔓佈範圍跟義大利的面積相當。

So there’s plenty of room right now for there to be widespread damage and lots of

因此離全面性傷害還有一段距離，也還有很多相對

relatively healthy reefs ― that’s something dive operators there really want you to know.

健康的礁石，那些潛水員非常想讓你了解的。

“The contrast in colors down there and the water ― when the light hits the different

「海底下礁石色彩不勝枚舉，有如光怪陸離般

colors down there and yeah it’s absolutely amazing.”

真的美極了。」

But the world’s coral reefs, including the Great Barrier Reef, have had a really hard

但是世界上現有的珊瑚礁，包括大堡礁，在最近幾年

time the past few years.

面臨困境。

After decades of degradation from local threats like pollution, and overfishing ―

經過幾十年來因為人為傷害和過度捕魚導致退化

coral reefs have now also undergone a record-breaking “global bleaching event.”

珊瑚礁正面臨史無前例的「全球白化危機」

That’s when coral turns white, which puts them at a high risk of dying.

也就是珊瑚礁白化，增加死亡風險。

It started in 2014, during the Northern Hemisphere summer.

一切始於2014年，北半球的夏天

Abnormally warm water caused corals in Guam and the Northern Mariana Islands to start

非常態溫水使關島和北馬里亞納群島的珊瑚

bleaching en masse.

全體白化。

By the end of 2014, corals around Hawaii, Florida and the Marshall Islands

在2014年年底，夏威夷附近、佛羅里達和馬歇爾島嶼的珊瑚

were bleaching too.

也開始白化。

When summer came around in the Southern Hemisphere, bleaching spreads to coral reefs

當南半球的夏天來臨，白化現象開始蔓延至

in the South Pacific and the Indian Ocean.

南太平洋和印度洋的珊瑚礁。

And towards the end of 2015, corals throughout the Caribbean were bleached too.

到2015年底，加勒比海的珊瑚礁也遭殃。

Hawaii’s corals bleached for a second time.

夏威夷的珊瑚礁遭遇二度白化。

By now El Nino was in full force, and when combined with global warming, it kept sea

聖嬰現象大肆襲來，伴隨全球暖化，使得海水

temperatures high enough to continue the bleaching event into 2016, hitting corals in Asia,

溫度過高，白化現象延續至2016年，波及亞洲、非洲東岸的

the east coast of Africa, and ... the Great Barrier Reef too.

珊瑚礁，還有...大堡礁。

― the worst bleaching, in fact, that the Great Barrier Reef had ever seen.

大堡礁從未遇到最嚴重的白化現象。

Bleaching continued into 2017, when the Great Barrier Reef was hit, again.

白化現象持續至2017年，大堡礁再度遇害。

ABC News: Australia’s Great Barrier Reef in grave condition tonight...

ABC新聞：澳洲大堡礁今晚病入膏肓...

FOX News: For the second year in a row, this video showing bleaching…

福斯新聞：連續兩年，白化現象的影像....

BBC News: Two-thirds of the Great Barrier Reef has now been devastated by severe coral bleaching

BBC新聞：三分之二以上的大堡礁遭受因海水升溫

which is caused by rising water temperatures.

導致的白化摧殘

Researchers first documented global coral bleaching in 1998 ― a record warm year ―

學者第一次紀錄全球白化現象是在1998年，飆高溫的一年

and it happened again in 2010.

2010又再度發生。

But this third global bleaching event is by far the worst.

但這第三次的白化危機是目前最嚴重的。

And looking at this temperature trend, you can get why people are starting to say goodbye

看到溫度趨勢，你可以了解到我們為什麼開始跟

to coral reefs.

珊瑚礁道別。

But to really get what makes them vulnerable, you have to understand how coral reefs work.

但在了解它們脆弱的原因前，你得先了解珊瑚礁的結構。

Corals are related to jellyfish and sea anemones, but you’ve probably noticed that they don’t

珊瑚和水母、海葵關係親近。不過，你可能已經發覺

look quite as... squishy.

它們看起來沒有那麼糊稠。

There's a couple reasons for that.

有幾個原因

For one thing, they live in colonies.

首先，它們是群居動物

Each coral structure is made of hundreds or thousands of individual

每個珊瑚架構是由上百個，上千個個別

coral animals called polyps.

珊瑚動物，水螅，所組成。

Each of these little bumps is where a polyp lives.

每個小凸出面都是水螅的生活地。

They’re easy to overlook if you’re snorkeling but if you look closely, you can see them,

在潛水的時候容易忽視它們，但如果你仔細看，可以看到，

especially at night when they’re less likely to be hiding.

尤其是夜晚的時候，它們比較不會藏匿。

Those polyps build a skeleton together.

這些水螅一同建起整個架構。

Not all corals do this but the ones that build reefs do so by creating a calcium carbonate

不是所有珊瑚都這樣，但那些組成礁石會在它們下方建造

skeleton underneath them, layer by layer.

碳酸鈣骨幹，一層又一層，

So the living polyps sit in little cups on top of an ever-expanding skeleton structure

因此這些水螅群體棲息在不斷延展的骨幹架構上

which, in turn, sits on top of the compacted skeletons of previous corals from thousands

這些骨幹架構又矗立在千年前遺留的

of years ago, otherwise known as limestone.

珊瑚骨幹，稱為石灰岩。

By building these structures with all these nooks and crannies, corals provide homes for

藉由建立這些充滿坑洞凹痕的結構，珊瑚提供了

hundreds of other animals and plants ― an estimated 25% of all marine species,

上百種動物植物一個家，約略有25%的海洋物種，

even though they take up less than 1% of the ocean floor.

儘管他們只占不到海底層面的1%。

Those reefs provide billions of dollars worth of economic value to people every year, through

這些礁石每年帶給人類幾十億的經濟收益，透過

fisheries, tourism, and protection from storm waves.

漁業、觀光業，也是湧浪的防護。

But here’s the thing: corals can’t build reefs on their own.

但重點來了，珊瑚無法自己建立礁石。

Coral reefs exist because of an incredible partnership between animal and plant.

珊瑚礁的形成建立在動植物的密切合作。

That’s because reef-building corals get the majority of their energy and nutrients

珊瑚的能量跟營養主要來自

from single-celled algae that live inside coral polyps.

棲息在珊瑚蟲內部的單細胞藻類。

It’s where they get their greenish-brown color too.

那也是牠們呈現棕綠色的原因。

They’re called zooxanthellae, and like other plants, they make energy from sunlight, that’s

牠們稱為蟲黃藻，像其他植物一樣，牠們行光合作用

why coral reefs mostly grow near the surface of the ocean ― where the sun shines.

這解釋了為什麼珊瑚礁大都生長在有陽光照射的海平面附近。

But this partnership breaks down under heat stress.

然而這個關係在熱壓力下崩然而解。

After multiple weeks of temperatures even just a couple degrees celsius hotter than

經過數幾周，海水溫度超出牠們能接受的最高溫度

the maximum temperature that they’re used to, The photosynthetic system in the algae starts

攝氏幾度，海藻的光合作用開始

to accumulate reactive oxygen molecules like hydrogen peroxide,

累積反映性氧分子，類似過氧化物，

which leak into the coral polyp cells.

之後滲進珊瑚蟲細胞內。

To protect themselves from damage, the coral polyps kick the algae out of their bodies,

為了保護自己，珊瑚蟲將這些藻類踢出自己身體，

leaving the pale skeleton showing through.

最後留下的就是光禿禿的骨幹。

By warming the planet, we are, among many other things, breaking up the team that built

因為我們所造成的暖化問題，破壞了整個海洋多樣性生態所需

the ocean’s most diverse ecosystem.

的合作關係。

But bleached corals don’t necessarily die.

但白化珊瑚不一定會導致死亡。

What happens next depends on how severe and long-lasting the high temperatures are.

界下來就得看這場高溫的嚴重性及時間性了。

When researchers assessed the damage to the Great Barrier Reef in 2016,

當學者檢視2016大堡礁受到的傷害時，

they found that coral death was concentrated in the northern section of the reef, where

他們發現死亡的珊瑚集中在礁石北部的區域，

bleaching had been the most severe.

那邊白化現象最嚴重。

In the central section, 33% of the reefs bleached severely, but there was only around 6% mortality.

在中部區域，33%的礁石嚴重白化，但死亡率只有6%。

That’s because zooxanthellae can return to a coral colony within a few weeks if the

原因是蟲黃藻在水溫降下後幾個禮拜內

water cools back down fast enough.

會回歸珊瑚礁。

If not, the coral dies from starvation or disease.

如果沒有，珊瑚則死於飢餓或疾病。

If enough coral colonies die, a reef can get taken over by fuzzy brown seaweed.

如果過多珊瑚死亡，整個礁石將被棕色水草覆蓋。

Some coral reefs have transformed into… this.

有些珊瑚礁已經成了這副景象

If there are enough fish and other grazers to eat up the seaweed, new coral larvae can

如果有足夠的魚或草食動物吃掉這些水草，新的珊瑚幼蟲能

settle there and the reef can start building up again.

在上面棲息，礁石又能再度建起。

After the 1998 bleaching, the corals of the Great Barrier Reef eventually recovered.

在1998年白化現象後，大堡礁的珊瑚最終都恢復了

But it takes a decade or more for even the fastest growing corals to build back up, and

但這個癒合期，就算是生長最快的珊瑚，也需要十年以上的時間

that 10 year timeline assumes one very important condition:

而且有個很重要的條件

That they don’t bleach all over again.

不能再度受白化傷害

And they almost certainly will.

但幾乎都會。

Climate models project that in the coming decades, the conditions now causing mass bleaching

具氣候模型預估，在接下來幾十年內，大量白化的現象

will become increasingly frequent, until eventually they happen every summer.

將愈趨頻繁，到每年夏天發生一次。

How soon that happens depends a lot on whether we start cutting our greenhouse gas emissions.

這個預期的急遽性只能看我們能否減少溫室氣體排放

If we don’t, annual bleaching conditions are projected for parts of

如果沒有，每年的白化現象將在世紀中期的時候

the Great Barrier Reef by mid-century.

預估降臨大堡礁。

At that point, few coral reefs could survive.

在那個時候，多數珊瑚礁將難逃一劫。

If we buy them more time by slowing down global warming, corals and their zooxanthellae may

如果我們延緩暖化，給牠們多點時間，珊瑚和蟲黃藻也許能

be able to acclimate or eventually evolve to tolerate warmer weather.

有適應的能力，最後接受更溫暖的環境

Coral reefs would still change, and probably still shrink,

珊瑚礁會不斷改變，也有可能不斷萎縮

but we could give them a better chance.

但我們能賦予牠們更好的機會

That’s why it doesn’t make sense to pronounce them dead.

因此宣布牠們的死不合理

This ecosystem is dynamic.

整個生態系統是變動不居的。

There are forces building it up, that are battling the forces tearing it down,

這是牠們生長的動力，也是抵抗傷害的動力。

and those factors vary by species & by location.

這些因素隨物種和地點而異

But with global warming, humans have sided against the world’s coral reefs

但隨著暖化，人類似乎站在珊瑚礁的對立面

to an unprecedented degree.

在很大的程度上。

Some of the damage is now unavoidable.

有些傷害是無可避免的

But the battle isn’t over, and it’s not too late for us switch sides.

可是這場戰鬥還沒停，現在換邊站也不遲

If you’d like to learn more about what the climate change is doing to the biodiversity

如果你想了解更多關於氣候改變對地球生態多樣性的影響

of our planet ― go over to audible.com/vox.

請搜尋audible.com/vox.

Their massive collection of audio books includes a lot of titles about climate change, including

裡面大量的有聲書涵蓋多樣氣候變遷的主題，包括

“The Sixth Extinction: An Unnatural History.”

【第六場滅絕:非常態歷史】

This is a Pulitzer Prize-winning book by Elizabeth Kolbert, covering not just coral reefs ―

這有普立茲獎得主伊莉莎白考白兒所撰寫的書，涵蓋不只珊瑚礁

but animals and plants around the world that are struggling to keep up with environmental change.

還有世界的動植物適應環境變化的困難

You can sign up for a free 30-day trial at audible.com/vox, and if you decide not to

你可以註冊30天免費試用，就算你不想

continue on with them ― you still get to keep your book.

繼續，還使可以收藏你的書

So sign up at audible.com/vox

所以趕快註冊audible.com/vox

and start spending your commute, or your cooking time, or your cleaning time,

開始用你通勤、煮飯或打掃的時間

learning more about the role that our species is playing

學習人類在地球的生命史中

in the history of life on Earth.

所扮演的角色。