What You Need to Know About Carbon Removal | Gabrielle Walker | TED

譯者: Zoe Walmsley 審譯者: Val Zhang

So I'm going to talk to you about carbon removals,

我今天跟大家談談「碳移除」，

and I’m going to start with this.

讓我從這個開始：

This is a woolly pig.

這是綿羊豬。

(Laughter)

（笑聲）

She's gorgeous, obviously,

牠很漂亮，無庸置疑，

and she’s also one part in a whole new set of approaches

牠亦是氣候變遷 全新解決方案中的一環。

for dealing with climate change.

They are all called carbon removals,

這些方案是「碳移除」──

and they all involve taking CO2 out of the sky

都是將二氧化碳 從大氣中分離出來，

and storing it somewhere safe.

儲存在安全的地方。

I’ll come back to the woolly pig later,

我稍後再談回綿羊豬，

but first, why do we need carbon removals?

首先，為何我們得施行碳移除？

Because I know what you’re thinking:

我猜你們在想：

isn’t it easier to stop putting the carbon in the atmosphere

從源頭禁止碳排不是更容易嗎？

in the first place?

And the answer is yes, of course it is.

答案是：沒錯，確實如此。

We have to do everything we can as fast as we can

我們得盡力、盡快，

to stop carbon getting into the sky

停止將碳排入大氣中，

and stop climate change getting worse.

防止氣候變遷惡化。

That should not be a controversial point of view at this meeting.

這點在此集會應該沒有爭議。

But the problem is ...

問題是──

we’ve left it too late.

為時已晚。

We can't now do it fast enough.

我們趕不及。

I've been working on climate change for more than 20 years,

我從事氣候變遷工作 20 多年，

and I’ve talked about it in boardrooms and classrooms

從董事會到教室，

and everywhere in between,

在許多地方談過這議題，

and I was shocked when I found this out,

這個發現還是讓我震驚，

but the science is utterly ...

但科學是如此地清楚明白：

utterly clear.

If we’re going to have a fighting chance of staying below 1.5 degrees,

若我們要將升溫控制 在 1.5 度以下──

that “safe limit,”

所謂的「安全範圍」，

we have to have carbon removals,

我們就得施行碳移除，

and it looks like we’re going to need a lot.

而且看來得移除很多。

Scenarios from the Energy Transitions Commission,

不論是能源轉型委員會、

from the International Energy Agency,

國際能源署、

from the Intergovernmental Panel on Climate Change,

還是政府間氣候變遷小組的預測，

have all shown that we’re going to need billions of tonnes of carbon removals

都顯示我們得移除 高達幾十億噸的碳，

between now and 2050

從現在開始到 2050 年，

to give us a chance of staying below 1.5 degrees.

升溫才有機會控制 在 1.5 度以下。

We’re going to need both reductions and removals.

「減碳」與「碳移除」得雙管齊下。

But there's another more heartening reason why we need carbon removals.

但施行碳移除還有個 令人振奮的理由：

They also give us a chance --

碳移除亦給我們機會──

our only chance --

唯一的機會──

not just to stop the problem getting worse,

不僅防止問題惡化，

but to make it better.

且能進一步改善。

Because even 1.5 degrees isn't actually safe.

因為 1.5 度仍不夠安全。

We’re not there yet, and we’re already experiencing the fires and the floods

當今的氣溫未超標， 就已火災、水災連連，

and the droughts and the storms.

還有乾旱、風暴等問題。

With carbon removals,

施行碳移除，

we can take our historical emissions out of the atmosphere.

我們能移除累積在大氣中的碳，

We can clean up the mess we’ve made,

收拾從前的爛攤子，

and we can give our world a chance to heal.

給地球癒合的機會。

So what do the removals look like?

那「碳移除」具體像是怎樣呢？

I’ve been talking to a lot of people about carbon removals,

我與許多人討論過碳移除，

from business executives to climate activists,

從企業執行長到氣候倡議者，

and they tend to go one of two ways.

他們的想法大致分為兩路。

其中一路是樹木，

They either think of trees

or they think of big, futuristic machines.

另一路則是具未來感的大型機器。

Nature versus tech;

自然與科技的對決；

green versus chrome.

綠色與金屬的對決。

But the more I’ve dug into carbon removals,

但我對碳移除了解愈多，

the more I’ve realized this is not the right way to think about them.

就愈知道這不是正確的解法。

Because the world is full of ways to store carbon.

因為世界早已充滿碳儲存的方法。

You can store it in trees,

碳可以儲存在樹木之中，

you can store it in soils,

也可以儲存在土壤中，

you can store it in the ocean,

可以儲存在海洋之中，

you can store it in buildings,

也可以儲存在建築物中，

you can store it in rocks,

可以存放在岩石中，

you can store it deep underground.

也可深埋在地層之中。

And every one of those approaches requires some combination of natural resources

而任何方式都需要結合自然資源、

and human ingenuity

人類的巧思、

and technology.

及科技的運用。

We’re going to need both nature and technology.

「自然」與「科技」得雙管齊下。

I'll show you what I mean.

我會說明為什麼。

So we start on the natural end of the spectrum with trees.

讓我們從「自然」 那一端的樹木談起。

Now, I still find it astonishing

至今，我仍覺得不可思議──

that every single tree and plant on Earth

地球上的每棵樹、 每株植物的軀幹，

has made its entire body directly from carbon in the air.

都直接仰賴大氣中的碳成長茁壯。

They’re incredible carbon capture machines,

它們是不可思議的碳捕捉機器，

and we’re going to need a lot more of them.

我們需要更多的樹。

But we also have to do it right,

但是我們要種得對，

because if you put trees in the wrong place ...

因為樹種在不對的地方──

they burn.

後果可能是森林大火。

We have to put trees in places where they foster biodiversity,

樹得種在促進生物多樣性的地方，

where they don’t compete with food for land

不與農作物爭地，

and where science and technology tell us they are likely to survive

自然與科技顯示 樹木能欣欣向榮之地，

even in the face of climate change.

不受氣候變遷所威脅。

Now, if you don’t want that CO2 from the burning trees

若不想讓樹木燃燒產生的 二氧化碳進入大氣中，

to get into the sky,

you can actually burn the wood deliberately in a power station,

我們能選在發電廠中燒，

capture the CO2

將二氧化碳攔截下來，

and bury it in a process known as BECCS,

再用 BECCS 技術將之封存，

which also gives you energy as a sideline.

過程中又產生了能源。

But if you want to keep the carbon locked up in the wood,

但若我們想將碳鎖在木頭中，

there are technological ways to do that as well,

現在也有科技可辦到，

like this one.

類似這個。看一下。

Look at this.

A whole new movement to use wood as a building material

一個全新的趨勢是用木材

建造現代的高樓大廈。

in modern, high-rise buildings.

That’s a good idea for at least three reasons.

這麼做至少有三大好處。

First of all, it keeps the carbon locked up in the wood.

第一，這麼做可將碳鎖在木材中。

Secondly, it displaces high-emitting materials like concrete.

第二，用木材取代高碳排的混凝土。

And thirdly, the buildings are gorgeous.

第三，木製建築物美觀怡人。

Now you can also use technology to help carbon stay locked up in soil.

我們當然也能運用科技 將碳封存在土壤中。

Storing carbon in soil sounds like a good idea,

將碳儲存在土壤中聽起來不錯，

and it is a good idea.

也的確是個好主意。

The question is how long does the carbon stay there?

問題是：碳能在土壤中多久？

Because if you change your agricultural practices for one year, two years,

因為若你改變農耕方式 一、兩年，應該沒問題。

that’s fine.

But if you ever go back to the old ways,

可是只要走回老路，

the carbon goes back up into the sky.

土壤中的碳就又回到大氣中。

That’s why this stuff can help.

而這可派上用場──

It’s called biochar,

生物炭，

and you make it by taking wood and burning it in the absence of oxygen

將木材在缺氧環境下燃燒

until you get this.

所得到的成品。

It locks the carbon up in the wood,

這技術將碳鎖在木材中，

and now it can’t burn away.

不會被燒掉。

Now, it turns out that biochar is very good for soils.

生物炭也對土壤有益。

In fact, Indigenous people in the Amazon have been using it for generations

事實上，亞馬遜的 原住民世代相傳

to improve the quality of their soil.

以此改善土壤品質。

We can do that on a much bigger scale,

我們能擴大規模，

improve the soil

改善土壤，

and lock up carbon.

同時將碳鎖住。

That’s nature

這是將自然、科技

and technology

and Indigenous wisdom,

還有原住民智慧

all in one sweet package.

三合一的巧妙方法。

Now you can use technology as well ...

當然我們也能運用科技

to speed up natural processes.

來加速整個過程。

So this is basalt.

這是玄武岩──

It’s a volcanic rock.

一種火山熔岩，

You can find it more or less everywhere on Earth,

世界各地多少都有分佈；

and it naturally takes up CO2 in a process called chemical weathering.

它在化學風化的過程中 吸進二氧化碳。

Unfortunately, it takes thousands of years to do it.

可惜的是，自然過程耗時數千年。

But you can speed up the process if you grind up the rock

現在我們能加快速度，

只要將岩石絞碎，散播在田野上，

and spread it on fields,

and then you can speed it up to just a couple of years.

整個過程就能降至短短數年。

And like biochar, it’s good for the soil.

就像生物炭，它也有益於土壤。

You get minerals in the soil where you need them.

土壤能得到所需的礦物質。

而當它最終流入海洋時，

And when it washes off into the sea,

還能幫忙處理另一個 氣候變遷的問題：

it can also help with another big bugbear of climate change:

ocean acidification.

海洋酸化。

And if we did this on two-thirds of the world’s croplands,

若將之用在 世界 2/3 的農地上，

we could potentially take up to four billion tonnes of carbon

每年能從大氣移除碳 高達 40 億噸之多。

from the atmosphere every year,

which is a very big chunk of what we need.

那占了目標總量的很大一塊。

Now, these approaches so far,

然而，目前這些方法，

like planting trees,

以種樹來說，

take a lot of land to be able to get them to scale.

需要很多土地才能達到有效規模。

But there is one approach

但還有一個方法，

where you can actually do it in a very small amount of land,

只需要少少的土地面積

but still get to scale.

就能做到相當的規模。

It’s called direct air capture,

那就是「直接空氣捕獲」技術，

and it basically involves massive electric fans blowing a lot of air

基本上就是運用巨大的風扇

將空氣吹入吸碳機中。

over a carbon capture device.

Now, OK, this does look like a big, futuristic machine.

這的確看來像台 具未來感的大型機器，

I admit that.

我承認。

But it’s still marrying technology with a natural process --

但這仍是將科技與自然過程──

geology --

地質學──結合起來。

because when you’ve captured the CO2,

因為捕獲的二氧化碳

you bury it deep underground.

被掩埋到地底深層。

This is an artist’s impression of a plant that’s being designed

這是畫家繪製的工廠模擬圖，

by Carbon Engineering in Texas.

由德州的 Carbon Engineering 所設計。

And its aim is that it will take up

這工廠的目標是

one million tonnes of CO2 from the atmosphere every year.

每年從大氣中捕捉 一百萬噸的二氧化碳。

And I love this bit --

而我最愛的部分是──

where does it go?

二氧化碳到哪去？

They put it deep underground in the same geological formations

他們將之深埋在地下，

在原本鑿出德州原油的地質層中。

that the Texas oil was originally squeezed out of.

I love the poetry of this.

我愛其中的詩意。

It’s like reversing the valve

就像扭轉閥門，

and putting the CO2 back where it came from.

將二氧化碳放回原本的來處。

And recent studies have shown that if you do that,

最近的研究顯示這個封存方法

98 percent of it will still be there in 10,000 years.

一萬年後仍有高達 98% 的原封存量。

When you put it down,

被掩埋的，就長埋地下。

it stays down.

This is still a little bit futuristic.

這聽起來還是有點未來感。

目前還在規畫設計階段；

It’s still in the planning and design stages,

but this carbon capture plant started operating this year.

但這個碳捕捉工廠今年開始運作。

規模較小，

A smaller scale,

but it’s already doing it.

但已經開始運轉了。

This is Climeworks and Carbfix in Iceland.

這是 Climeworks 及 Carbfix 兩家公司，在冰島的工廠。

They're using geothermal heat to power it,

他們利用地熱驅動，

and they’re putting the CO2 into the Icelandic basaltic rock.

將二氧化碳注入冰島的玄武岩中。

So one issue, though, with direct air capture,

目前「直接空氣捕獲」還有個挑戰──

is it takes a lot of energy to power those fans.

需要很多能源去驅動風葉，

And that energy obviously has to be green.

顯然得用綠能，

It has to be clean;

必須是乾淨的能源，

you can’t use fossil fuels for it.

不能使用石化燃料。

But it also makes it much more expensive than other techniques.

於是相對其他技術， 成本就貴許多。

And it takes energy to cook wood and to grind rock,

處理木頭及岩石也需要能源，

and so all of those approaches I’m talking about

所有這些我提到的方法

are currently much more expensive than planting trees.

與種樹相比仍是相對昂貴的。

But we can do something about that.

不過我們能對此著力。

We can invest in it now,

我們可以開始投資，

do the research and development

做研究開發，

and get them down the cost curve to make them affordable.

想辦法將成本降低到可行的範圍。

It worked for solar power;

之前的太陽能我們辦到了，

it worked for wind;

風能也是，

it can work for carbon removals, too.

所以碳移除也一定能辦到。

Remember, we have to get to very big scale:

別忘了，我們得實現的規模之大：

billions of tonnes of carbon removals by 2050.

在 2050 年前除去高達 數十億噸的碳。

But we can all help by reducing our emissions as much as possible

我們都能出力， 盡量減少個人碳排，

and figuring out how to remove the rest.

同時想辦法清除剩下的。

I’m not talking conventional offsets.

我不是指傳統的碳抵消。

You know, I put a tonne of CO2 in the air,

那種若我排放一噸的二氧化碳，

and I pay you not to put your tonne in the air,

就付錢請你不要排放你的那一噸，

but my tonne’s still there.

可是我排的那一噸仍存在。

No, what I mean is I put a tonne of CO2 in the air,

我指的是，若我排放 一噸的二氧化碳，

I pay someone to take a tonne out of the air, now or in the near future,

就付錢請人從大氣中移除一噸， 無論是當下或近期，

and we can get to zero and beyond.

這樣才能做到零碳排，甚至超過目標。

What goes up must now come down.

有上，如今就得有下。

And if we all do that,

若我們都能這麼做，

if we all make that commitment,

若我們都許下承諾，

then the people trying to make removals happen will have the finance

就能讓致力於碳移除 的人有經費、勇氣

and the courage

and the confidence to be able to get to the scale that we need.

及信心去達成我們 所需的碳移除量。

I don’t know which of all of these approaches,

我不知道所有的這些方法

in the end,

最後會是哪些真正派上用場，

are going to be the ones that we’ll have to use

to get us to the scale we need.

以達到我們所需的規模。

But I do know that we’re going to need a whole spread of them,

不過我確定我們需要各種方法，

with nature and technology working hand in hand

自然與科技並用，

to take CO2 out of the sky

移除大氣中的二氧化碳

and keep it out.

──永遠地移除。

Which brings me neatly back ...

這讓我回到一開始提的──

to the woolly pigs.

綿羊豬

(Laughter)

（笑聲）

Now, these woolly pigs live on an estate on the Isle of Mull,

這些綿羊豬住在 馬爾島上的莊園──

which is owned by Jim Mann’s Future Forest Company.

由未來森林公司的 老闆吉姆．曼所有。

And I know they don’t look very dangerous,

牠們或許看起來一點都不危險，

but they are actually the closest you can get

但其實是蘇格蘭野豬的近親，

to a native Scottish wild boar

without having to have a dangerous animals license.

且無需申請危險動物 執照便可豢養。

And they do what the Scottish wild boars used to do.

牠們也擅長蘇格蘭 野豬的拿手好戲──

They rootle up the undergrowth left over from selective grazing.

用鼻子將牛羊不吃的 灌木叢連根拔起。

They let the seed bank come to the surface

將土壤下的種子庫翻到地面上，

so that native trees can start to grow

讓原生樹種開始生長， 吸取大氣中的二氧化碳。

and start to take up CO2 from the sky.

They're also planting trees in this lovely place.

除此之外，這裡也種樹。

Native broadleaf like oak and this beech tree,

有原生闊葉種的橡樹及山毛櫸，

and it’s plenty wet enough on the Isle of Mull

而且馬爾島絕對夠濕，

森林自燃的機率不高。

that they’re not likely to burn.

So that’s so far, so natural

所以到目前為止，非常自然。

But they also have machines.

但同時他們也利用機器。

This one is getting ready to cook wood for biochar to go on the soils,

這台機器用來加溫木頭， 製成生物炭撒在土壤上，

and they’ve also got a quarry with basalt.

還有一個玄武岩礦場，

They’re quarrying basalt rock.

可以開採玄武岩。

They’ve got machines to grind up the rock,

用機器將岩石打碎，

and they’ve got machines to spread it on the fields.

再用機器將碎石撒在田間。

That's three carbon removals approaches in one beautiful place.

一個美麗的地方同時施行 三種不同的碳移除方法。

Now, it’s just one estate,

雖此案例的規模不大，

but all of these approaches and more are hugely scalable.

但這些碳移除方法 都能輕易地被複製擴散。

The world is full of places where you can plant trees

世界上有許多地方──可種樹，

and put carbon in soil

儲碳於土，

and grind up rock and spread it

覆蓋碎石，

and capture CO2 from the air

捕捉大氣中的二氧化碳，

and find places to store it underground.

然後將之深埋地底。

All of those things.

上述的那些方法，

And there’s hundreds --

此外現在有許多人正在努力

thousands of people working right now

to get those carbon removals approaches out of the textbook

實現教科書中的碳移除方法

並實際運用，

and into practice,

and to help us --

幫助我們──

God help us --

上帝也幫幫我們──

reverse the damage we have done

扭轉我們所造成的傷害，

and start the process of climate healing.

展開療癒氣候的過程吧！

And when I sat on that hillside,

當我坐在那個山坡上，

and I saw the pigs rootling

看到綿羊豬翻土、

and the trees growing

樹木欣欣向榮、

and the machines getting ready to cook and grind,

不同的機器加溫木頭、打碎岩石。

I loved it ...

我深愛這景象──

because I experienced an emotion

因為我感受到

that those of us who work on climate change

從事氣候變遷工作的人

very rarely experience.

罕能感受到的──

I felt hope.

希望。

Thank you.

謝謝。

(Applause and cheers)

（掌聲與歡呼聲）