The Unexpected, Underwater Plant Fighting Climate Change | Carlos M. Duarte | TED Countdown

譯者: Regina Chu 審譯者: Yi-Ping Cho (Marssi)

I'm here to unveil a new carbon-removal technology,

我來跟大家介紹一項新的除碳科技，

one out of sight and uncelebrated.

超傑出，卻躲在角落默默無名。

Meet our champion: seagrass.

這就是我們的冠軍：海草。

A very unlikely champion,

令人跌破眼鏡的冠軍，

but yet a remarkable power of carbon removal.

卻擁有超凡的除碳能力。

Seagrasses occupy only 0.1 percent of the seafloor,

海草僅佔海床的 0.1%，

but they remove one-third of all of the carbon

每年卻可以除去 1/3 的總碳，

that gets sequestered in the seafloor annually.

並將之封存在海底。

They are no ordinary seagrasses,

它們可不是一般的海草，

and yet, we didn’t know much about them.

我們對它們卻所知甚少。

When I started my journey of research and science with seagrasses

四十年前，我開始研究海草的時候，

about four decades ago,

we knew that they were flowering plants

我們知道它們是開花植物，

that had adapted to grow and colonize the ocean,

已經移居並適應在海中生長，

but we didn’t know how amazing the adaptation [were] required

但是我們不知道要實現這樣的壯舉

to [be to] achieve this feat.

需要花多少適應力。

In fact, only seven years ago,

事實上，也不過七年前，

we published the first genome sequence of a seagrass,

我們才發布了第一個海草基因組定序，

and we were mesmerized at the amazing adaptations that were required

我們被能移居海洋

所需要的驚人適應力迷住了。

to be able to colonize the ocean.

And now we understand why only 17 species

我們現在知道為什麼只有十七種物種

from among 300,000 or so species of flowering plants

能異於其它三十萬種開花植物，

that are present in the biosphere

它們都一樣這個生物圈生存，

have conquered the ocean.

卻只有這十七種征服了海洋。

Seagrasses grow by extending a rhizome --

海草靠橫向延伸根莖生長，

that is a subterranean stem

根莖就是地下莖，

that elongates at rates of about one centimeter

以每年一公分

to about five meters per year,

到五公尺的速率伸長，

and they branch and extend along the seafloor,

它們會在海底分支、延伸，

forming large clones.

形成大型的無性繁殖系。

We knew that clones can be quite large,

我們已經知道這種無性繁殖系 可以非常龐大，

but we were surprised when, in the Mediterranean,

但是我們還是很驚訝，

we found, 10 years ago,

十年前在地中海發現的

a clone that occupied 15 kilometers;

無性繁殖系，佔地 15公里；

that is the size of the island of Manhattan.

那是曼哈頓島的大小。

And this is a very remarkable clone,

這是一個非常了不起的無性繁殖系，

but we also calculated that the seed that gave rise to this clone

但是我們也計算出 產生這個無性繁殖系的種子，

germinated in the seafloor 200,000 years ago.

於二十萬年前在海底萌芽。

This is one of the oldest living things on the planet,

這是地球上數一數二老的生物，

and the meadow where this megaclone is growing

這片巨無霸無性繁殖系草地

is now recognized as a marine World Heritage site.

現在被正式認定為海洋世界遺產。

Off the island of Ibiza,

在伊比薩島外海，

this meadow occupies about 800 square kilometers

這片草地佔地約八百平方公里，

and is now recognized as a protected area,

現在被認定為保護區，

not just because of the long life span of the clones

因為這個無性繁殖系不但長壽，

but also because of the biodiversity it supports.

還支持生物多樣性。

But we also found that this meadow

但是我們也發現這片草原

is also the champion of carbon sequestration in the biosphere,

也是生物圈中的碳封存冠軍，

with one hectare of this seagrass sequestering as much carbon

一公頃的海草能封存的碳，

as 15 hectares of pristine Amazonian forest.

相當於 15 公頃 原始亞馬遜森林所封存的。

Finding [out] how this is possible was a path of discovery.

找出這件事能發生的原因 是一趟發現之旅。

First, the canopies of these plants are very large,

首先，這片植物的冠層非常大，

and they are among the most productive ecosystems on Earth,

而且生產力是地球生態系統中 數一數二的，

pumping carbon dioxide into organic matter at amazing rates,

它們以驚人的速度吸收 二氧化碳轉成有機物，

that produce a lot of carbon,

產生許多碳，

much of that being sequestered in the soils

大部分都會以根莖及根的型態 封存在土壤中，

as rhizomes and roots that are very hard to decompose.

非常難分解。

The large canopies also form a web

大的冠層也形成一個網，

that dissipates energy and filters out particles from the flow

分散能量並過濾水流中的粒子，

that settle, then, in the seafloor, protected from being resuspended

然後讓它沉澱在海床，

被冠層保護罩蓋著，不會再懸浮。

by the protective cover of the canopy.

And these particles in the seafloor decompose very slowly,

沉在海底的粒子分解極慢，

because the seafloor and the soils of seagrasses

因為海床及海草的土壤

are devoid of oxygen,

缺氧，

and that slows down microbial decomposition.

因而減緩微生物分解。

So this carbon accumulates and is preserved in the soils.

所以碳就在土壤中累積並保存。

And there's one more reason

還有一個原因

why these seagrass meadows are so effective at sequestering carbon.

讓海草原在固碳方面非常有效。

And it’s that, unlike forests,

原因就是，不像森林，

where carbon in the soil gets emitted back to the atmosphere

森林土壤中的碳

會因森林大火而排回大氣層──

with wild forest fires --

which, unfortunately, are becoming more frequent with climate change --

這很不幸的因氣候變遷而更普遍──

there are no fires underwater,

水裡沒有火災，

so the carbon that settles in the soils of seagrass is safe

所以沉澱在海草土中的碳很安全，

and accumulates over thousands of years, safely.

可以很安全地在土裡沉積數千年。

In fact, seagrasses not only grow along the seafloor --

事實上，海草不只沿著海床生長──

they also raise the seafloor upwards

它們還會升高海床，

at rates of one to four millimeters per year,

以每年一到四公釐的速度增高，

and they do so, over centennial timescales,

而且海草這樣做已經很久了，

所以經過幾百年後， 這些海草生成礁石，

to the point that these seagrasses form reefs,

such as this four-meter-tall reef of seagrass peat

就像這座四公尺高的海草泥炭礁，

that is found in the Mediterranean.

這是在地中海發現的。

And this is not the tallest seagrass reef that has been discovered.

這還不是最高的海草礁。

My colleagues have dug out a seagrass reef

我的同事找到一個海草礁，

that is 12 meters tall, three times this size.

有 12 公尺高，比這個大三倍。

Just imagine the amazing amount of carbon

想像一下已經有多少碳

that is being held in these seagrass reefs.

儲存在這片海草礁裡。

But it is not only carbon.

但這不僅是碳。

The seagrass reef protects the shorelines,

海草礁還保護海岸，

protects our infrastructure,

保護我們的基礎建設，

protects our property and protects our lives.

保護我們的財產及我們的生命。

And this protection becomes particularly important

這樣的保護現在變得特別重要，

at a time when climate change is raising sea levels

因為氣候變遷造成海平面上升，

and is also leading to increasingly strong storms and cyclones.

也導致愈來愈強的風暴及颶風產生。

So very often,

所以很多時候，

seagrasses form the first line of defense for the shorelines.

海草是海岸線防禦的第一防線。

So as we became aware of the important role of seagrass

就在我們意識到

in carbon sequestration,

海草在碳封存的重要作用，

and also in defending our shorelines,

以及如何幫我們防禦海岸線的時候，

then we were almost too late to benefit from those protections,

似乎為時已晚， 我們無法從這些保護中受益，

because, sadly, we had lost a lot of seagrass in the ocean.

因為，可悲的是， 我們已經失去了很多海草。

In the 1930s,

1930 年代，

disease wiped out seagrass along both sides of the Atlantic.

疾病殲滅了大西洋兩岸的海草。

And as they were starting to recover,

就在它們開始復原的時候，

sewage input and agricultural runoff

污水及農業逕流湧入，

led to mortality of seagrass along the shores of all continents,

導致各大洲沿岸的海草死亡，

and that was aggravated further with mechanical damage,

再加上機械式損害，更是雪上加霜，

such as the dragging of this anchor from a megayacht in the Mediterranean

就像這艘地中海超級遊艇拖曳的錨，

that is plowing away this millenary seagrass,

根本就是在這片千年草地上割草，

exposing the sediment and resuspending it

暴露沉積物並讓它重新懸浮，

so that it will be emitted back into the atmosphere as carbon dioxide.

就會讓它以二氧化碳的形式 重新排放回大氣中。

And that was compounded with dredging, trawling and coastal works

再加上疏浚、拖網和沿海工程

that impacted seagrass.

都會影響海草。

So by the end of the 20th century,

所以到了 20 世紀末，

we calculated that one-third of the known seagrass areas in the ocean

我們算出三分之一海洋中的已知海草區

had been lost.

已經消失了。

And yet efforts to protect them became urgent.

保護行動因而急迫。

But we can only protect what we know,

但是我們只能保護我們知道的，

and our knowledge of the distribution and area of seagrasses in the ocean

我們對海洋中海草的分布及區域

is still very poor.

所知非常有限。

Our estimates range between 150,000 square kilometers

我們預估大概是十五萬平方公里

to one million square kilometers.

到一百萬平方公里之間。

And narrowing down this uncertainty is very, very challenging.

縮小這種不確定性是非常非常大的挑戰。

In fact, it can only be done by scuba divers,

事實上，我們只能請潛水員下去看，

because seagrass meadows cannot be resolved from satellites

因為海草原既不能用衛星、

or from airborne sensors,

也不能用空中的感應器量測，

because the deeper parts cannot be differentiated

因為在海底深處無法區分出是海草，

from other types of grounds and seafloors.

還是海床或其他的平面。

So we are actually partnering with much better swimmers than we are,

所以我們跟比我們還會游泳，

but that share our interest in seagrass meadows.

又跟和我們一樣對海草原 有興趣的健將合作。

We are partnering with green sea turtles,

我們跟綠蠵龜合作。

which are mostly feeding on seagrasses,

牠們靠海草為食，

so we track them with satellite devices

所以我們用衛星設備追蹤牠們，

to find out where their feeding grounds are,

找出牠們在哪裡覓食，

and by doing this, we are finding and discovering

如此一來，我們就能找出並發現

new seagrass meadows in the Indian Ocean and the Red Sea,

位於印度洋及紅海的海草原，

which were poorly studied.

這兩個地方我們非常不瞭解。

And in the Bahamas,

在巴哈馬群島，

we are now partnering with tiger sharks,

我們現在跟虎鯊合夥，

because we found that in the Bahamas,

因為我們發現在巴哈馬，

tiger sharks spend about 70 percent of their time

虎鯊花大約 70% 的時間

cruising over seagrass meadows.

在海草原上巡遊。

And we instrumented, last year, for the first time,

去年我們還首次在一條虎鯊上

a tiger shark with 360-degree cameras,

裝了一個 360 度的廣角鏡頭，

which are sitting on the fin of the shark

就裝在鯊魚鰭上，

so that when the cameras pop up to the surface,

所以每當攝影機浮出水面，

then we retrieve the footage,

我們就收集影片，

and we can ascertain in which areas of the track there were seagrasses.

我們就可以確定 在跟蹤區域上哪裡有海草。

So using tiger sharks as partners,

所以以虎鯊為合作夥伴，

we have now discovered that the Bahamas' banks --

我們發現了巴哈馬沿岸的沙洲──

which a US astronaut, Scott Kelly,

美國太空人史考特．凱利

deemed to be the most beautiful sight from space

認為這是從太空看世界上最美的景觀，

when he shared this photo that he took from space --

他當時分享了這張他從太空拍的照片──

is actually the largest seagrass meadow in the ocean.

其實是海中最大的海草原。

And we are now growing policies to protect seagrasses

現在我們增訂政策以保護海草

and improve water quality

及改善水質，

so that we can recover seagrasses.

這樣我們才能復育海草。

And I tell you what, these policies are working.

而且我要告訴你們，這些政策有用。

And over the last two decades,

過去二十年，

we have seen a rebound of seagrasses

我們已經看到海草復原，

following almost a century of sustained decline.

在近一個世紀的持續減少後，

Now seagrasses are starting to expand and recover

現在海草正開始增長及恢復，

along the shores of Europe, North America, Japan, Australia and China.

沿著歐洲、北美、日本、 澳大利亞和中國的海岸。

And this is only the beginning,

這只是個起頭，

because we can do more than just protect seagrasses

因為我們還可以做更多的事，

不只是保護海草， 等著它們長回來而已。

and wait for them to come back.

We can engage in active restoration,

我們可以更積極的復育，

such as my colleagues in Virginia have done.

比如我的同事在維吉尼亞做的。

And in the early years of this century,

在本世紀初，

they released 7.5 million seeds of seagrasses in South Bay,

他們在南灣播下 七百五十萬顆海草種子，

in the coastal waters of Virginia.

撒在維吉尼亞沿海水域。

And 16 years later,

16 年後，

the seagrass has expanded to 20 square kilometers,

海草已經擴張到 20 平方公里，

and by now it has covered, already 36 square kilometers.

現在已經覆蓋了 36 平方公里。

The amount of carbon that this restored seagrass meadow has trapped

這片復育的海草原捕捉儲存的碳量，

is so important that it has led the Commonwealth of Virginia,

重要到維吉尼亞州政府，

that owns these waters,

──這片海域的主人──

to pass a bill that regulates how carbon grades

通過一項法案，

from seagrass restoration

規範海草復育的碳交易

should be reinvested back in further restoration of seagrass,

應該再投資回來進一步復育海草，

and also in improving our understanding of seagrass ecology.

並提高我們對海草生態學的了解。

But seagrasses are more than just carbon.

但是海草不僅僅是碳。

They also have seeds,

它們還有種子，

and my friend and three-star Michelin chef, Ángel León,

我的朋友安荷．里昂， 他是米其林三星廚師，

has released this year an important development,

今年發布了一項非常重要的發展，

which is that these seeds can be consumed by humans

就是這些種子可以被人類食用，

as marine rice.

這些種子是「海米」。

And this is a wonderful crop,

這是一種非常棒的作物，

one that does not require arable land, fresh water,

不需要耕地淡水，

neither fertilizers nor herbicides or pesticides.

也不用施肥灑農藥。

And because we only need to clip the flower and shoots where the seeds are,

而且因為我們只需要剪下 種子所在的花及莖，

we don't need to harvest the plant,

不需要收割整株植物，

so the meadow continues to sequester carbon,

草原還可以繼續封存碳，

promote biodiversity and defend our shorelines.

促進生物多樣性，保衛我們的海岸線。

And these findings, in the past decade,

過去十年的這幾項發現，

have made me believe that it's time to ditch the idea

讓我相信是時候放棄

that seagrasses are the ugly ducklings of environmental conservation,

海草是環保醜小鴨的想法了，

as I nicknamed them 15 years ago,

15 年前我給它們取了這個綽號，

frustrated, because at that point,

當時我很挫折，

not even conservation NGOs cared.

因為連非政府保育組織都看不上它們。

Now we know that seagrasses are beautiful swans --

現在我們知道海草是美麗的天鵝──

which actually eat seagrass leaves and rhizomes --

天鵝其實會吃海草的葉子及地下莖──

and healthy seagrass meadows are harbingers of a healthy ocean.

而且健康的海草地是健康海洋的先兆。

And I am inspired by the tide change

扭轉的情勢激勵了我，

from a century of loss of seagrass

從一個世紀的海草流失

to two decades of recovery

到二十年的復育，

to imagine that we can actually do better.

想像一下我們其實可以做得更好。

We can expand this success story to the rest of marine life,

我們可以將這個成功的故事 擴展到其他的海洋生物上，

and last year, we published a paper in the journal "Nature,"

去年，我們在《自然》期刊 上發表了一篇論文，

where we pledged that it's possible to recover

我們保證絕對有可能

and rebuild the abundance of life in the ocean by 2050.

在 2050 年復育及重建 海洋豐饒的生命。

Just imagine that it is within our [grasp]

想像一下，我們能交出

to hand over a healthy ocean to our children and grandchildren.

健康的海洋給我們的子孫。

And as we do so,

與此同時，

we can also step up in our race to stabilize our climate.

我們還能加速穩定氣候。

Thank you.

謝謝。

(Cheers and applause)

（歡呼聲及掌聲）