How Biochar Removes CO2 from the Air -- and Helps Farmers Thrive | Axel Reinaud | TED

譯者: YuChieh Huang 審譯者: Shelley Tsang 曾雯海

Imagine a farmer growing coffee in Nkongsamba,

試想一位在喀麥隆蒙哥州 恩康桑巴種咖啡的農民。

in the Moungo region of Cameroon.

Let’s call him Mr. Ewané.

我們就稱這位農民為伊萬納先生，

Mr. Ewané lives out of a small plot of land,

伊萬納住在一塊小土地旁

growing food to feed his family,

靠著種植農作物、咖啡賺取 微薄的收入養活他的家庭。

and coffee, to earn a very modest income.

While many of us in the Western world debate about climate change,

雖然在西方世界的我們有許多人 爭辯著氣候變遷議題。

Mr. Ewané knows it is real.

伊萬納先生也知道這是事實。

The rainy season is becoming more erratic,

雨季天氣也越來越無法掌握，

impacting his coffee production

影響到了他的咖啡收成，

that has been declining year after year.

產量年復一年下降。

Mister [unclear] is by no means responsible for climate change.

伊萬納先生絕對不需要為 氣候變遷負責。

His own CO2 emissions are below 200 kilograms per year,

他自己每年二氧化碳的排放量 少於 200 公斤，

while we in the developed world emit 30 to 60 times more than he does.

生活在已開發國家的我們排放量 則是他的 30-60 倍。

Our way of living -- his problem.

我們生活的方式 -- 造成他的問題。

The great story is that Mister [unclear] can improve his standard of living

故事是伊萬納可以改善他的生活水準，

while removing CO2 from the atmosphere and helping fight climate change.

藉由移除大氣中的二氧化碳， 幫助減緩氣候變遷

This is not about trees.

這不是關於樹木，

It's much smaller.

這要小的多。

Sounds interesting?

聽起來是不是有趣?

Well, bear with me.

嗯，容我再詳述。

In order to fight climate change,

為了對抗氣候變遷，

we need to reduce, like crazy, our greenhouse-gas emissions,

我們需要減少一半的溫室氣體排放，

halving, in the next 10 years,

過去十年裡

the 50 billion tonnes that we emit annually,

每年排放 500 億噸，

and then aiming to halve again in the following decade.

在接下來的十年裡需要再減半，

While reduction is needed,

雖然減排是必須的，

it will not be enough to get us to zero emissions,

不過須等到我們達到零排放

[which] is needed to stabilize climate.

才能讓氣候穩定下來。

There will be, for a very long time, residual emissions,

這會需要很長時間，剩餘的排放，

from some industrial processes,

來自工業排放、

from aviation, from agriculture, etc.

來自航空業、來自農業等等。

Billions of tonnes of residual emissions,

數十億噸的剩餘排放，

even when we have reduced all that we can.

即使我們已經盡我們所能減排，

So we can't be zero emissions,

我們不可能零排放，

but we can be net-zero emissions:

但我們可以淨零排放；

that is, removing from the atmosphere, as much CO2 as we emit annually.

也就是自大氣環境中移除二氧化碳， 以抵銷我們每年排放量。

And maybe, one day, remove more than we emit,

或許，某天，可以移除的比我們排放的多。

to restore our climate balance.

以恢復我們的氣候平衡。

That's when Mister [unclear] comes into play.

講到這裡，這就是伊萬納先生 要扮演的角色。

He has been capturing CO2 through the growth of his crops,

他種植的作物生長過程 可捕捉二氧化碳。

year after year.

年復一年

Photosynthesis that drives the growth of crops

光合作用讓作物得以生長。

is by far the most efficient way to capture CO2 from the atmosphere.

這也是目前為止捕捉二氧化碳 最有效率的方式。

But if nothing is done,

但如果甚麼都沒做，

that same CO2 goes straight back into the atmosphere

同樣二氧化碳的量會返回大氣層。

when plants decompose or are burned.

當植物分解或燃燒時。

But the good news is that we can stabilize the carbon

不過好消息是我們可以固定 廚餘中的碳，

contained in the leftovers

from the coffee cherries of Mister [unclear].

固定伊萬納先生的咖啡果實中的碳。

That means we can remove CO2 year after year

這也就表示，我們可以每年都移除二氧化碳，

and help fight climate change.

以幫助抵抗氣候變遷問題。

And what if that same technology

假如同樣的科技

would allow Mister [unclear] to improve the productivity of his fields,

可以允許伊萬納改善他的作物產量

hence his standard of living?

提高他的生活水準呢?

Now you start to see the opportunity.

如今，已可以預想這種可能性，

It’s called “biochar.”

這種技術稱之為 “生物炭“。

Let me say right away that biochar is by no means a magic wand

我會說，生物炭無疑是一個魔杖

that will take us out of the climate crisis.

讓我們遠離天氣變遷造成的危機。

It's one of the many solutions to help remove CO2 from the atmosphere.

這是自大氣中移除二氧化碳的 其中一種方法。

But if used smartly, it's just an amazing thing.

如果我們運用得當， 它會是令人驚奇的技術。

Biochar is carbon resulting from pyrolysis,

生物炭材料是來自熱裂解後的碳。

that is, heating biomass at high temperature without oxygen.

也就是，高溫脫氧加熱生質物。

Any kind of plant-based, dried biomass

任何的作物、乾重約有一半都由碳組成

contains about half of its weight in the form of carbon.

And it is this carbon that is extracted and stabilized

而且，這是碳被萃取和穩定 製造生物炭的方法。

to create biochar.

Biochar is essentially carbon

生物炭基本就是碳

that was captured from the atmosphere by plants

植物從大氣中捕捉碳、

and transformed into a very stable form of carbon.

並轉換成非常穩定的碳的形式之一。

It looks like charcoal powder.

它看起來很像木炭粉，

The first amazing property of biochar

生物炭第一個令人驚嘆的性質是

is that it remains stable for hundreds of years,

可以在環境中保持穩定好幾百年，

even if put in the soil,

即使它被放到土壤裡

where biomass will normally degrade.

通常生質物在土壤裡會被分解。

Think about it.

想想看，

The CO2 captured by plants through photosynthesis

植物透過光合作用捕捉二氧化碳，

and converted into biochar

並轉換成生物炭。

stays in the soil, and so stays away from the atmosphere,

保留在土壤中，不再逸散到大氣中

for hundreds of years.

持續好幾百年。

So we have a carbon removal situation,

因此我們有了一個移除碳的情境，

and this is good for the climate.

而且這樣對氣候有好的影響。

The second amazing property of biochar

生物炭令人驚嘆的第二件事

is that, when mixed with topsoil, it improves the soil quality,

是它與表層土壤混合之後 可以改善土壤品質、

hence, crop yields.

提供作物產量。

This is especially true for poor, dry and acidic soils that lack nutrients.

這尤其對於那些貧脊、乾燥和酸性 缺乏養分的土壤尤其有效。

Putting carbon in the soil

把碳放到土壤裡，

has been known empirically for hundreds of years

好幾百年來，人們就已知這是一種 改善土壤品質的方法。

as a way to improve soil quality.

It was used in some parts of Amazonia prior to the arrival of Europeans,

在歐洲人來到之前，亞馬遜地區的人們 就已使用此法。

and it's still used today in some parts of Asia.

在亞洲部分地區，現在也仍被使用。

Biochar's effects on soil come from its microstructure.

生物炭對於土壤的影響源自 它的微觀結構。

When magnified, biochar looks like a carbon sponge,

放大看生物炭看起來就像一塊碳海綿，

with hundreds of square meters of surface per gram of biochar.

每公克的生物炭表面有好幾百平方公尺

This ultraporous structure helps retain water and nutrients.

這超多孔的結構可以保留水分和養分。

Biochar also favors the development of microbial life into the soil

生物炭也有助於微生物進入土壤中生活

that is most needed for plants to absorb nutrients.

這些微生物可以幫助植物吸收養分。

And last, given its high pH,

最後一點，可以提供pH值，

biochar helps counter the negative effects of soil acidity.

生物炭可以中和土壤酸性的負面影響。

Using biochar allows to reduce, or even eliminate,

利用生物炭可以減少、甚至去除

the need for fertilizers,

肥料的使用需求。

cutting costs for farmers and helping the environment.

減少農民的成本、也有助於環境。

And the great thing is that, given its stability,

最好的事莫過於它的穩定性，

biochar needs to be applied just once,

生物炭僅需要施用一次，

and its effects last for decades.

而其影響會持續數十年。

And then, there's a bonus.

另外，還有一個額外好處。

The production process of biochar generates flammable gases.

生物炭產製過程會產生可燃氣體。

Part of those gases are used to heat the reactor

有些氣體可以用來加熱 生物炭產製的反應爐。

where biochar is produced,

and the remaining gases can be used to generate renewable heat or electricity.

而剩餘的氣體可以用來生產 再生熱能或電力。

So not only the production process of biochar

因此，不只是產製生物炭的過程

is self-sustained,

是自給自足的。

but it is a source of additional renewable energy.

同時，它也是再生能源的另一個來源。

Quite incredible.

相當不可思議。

So we have this amazing product that is a climate solution,

所以我們有這麼好的產品 做為氣候變遷解方、

an agricultural solution

農業的解方、以及再生能源解決方案

and a renewable energy solution.

And now, you start to wonder:

現在，你會開始想:

"How come this biochar thing that he's talking about

他說的這個生物炭

is not widely used all over the place?

怎麼沒有廣泛的在各處被應用呢?

What's the problem?"

問題是甚麼呢?

Well, the answer is plain and simple:

嗯，這個答案很簡單明瞭:

costs.

成本。

Most biochar produced in the last years

過去幾年內，大部分產製的生物炭

had to be sold at prices as high as 1,000 dollars per tonne,

每噸高達 1000 美元的價格售出，

to cover production costs.

以支撐生產成本。

That made biochar uneconomical for most usages.

因此，大部份的運用會讓生物炭 變得不夠經濟實惠

And so, despite its wonderful properties, it has remained a niche product.

所以，儘管它的優良特性， 生物炭仍然是利基產品。

But things started to change in the last couple of years.

在過去幾年內事情開始有了轉變。

The recognition of climate change started to shift our behaviors,

對於氣候變遷的認知開始 改變了我們的行為

leading companies and states to commit to net-zero trajectories.

也帶領了企業、國家承諾淨零路徑。

Some innovative companies

有些技術創新公司

committed to an accelerated net-zero trajectory;

承諾加速的淨零路徑；

started to buy, at a high price, biochar-based carbon credits

開始採購高價的生物炭的碳權

for their long-term CO2 removal effects.

取得長期能移除二氧化碳的效益。

That changed the economics of biochar,

這就瞬間改變了生物炭的經濟，

as all of a sudden,

the climate benefits of biochar

生物炭對於氣候的好處

could help subsidize its agricultural usage.

可以幫助補貼農業的使用。

As a consequence,

結果導致，

biochar is emerging as a credible CO2 removal solution,

生物炭是新興碳權解決方案之一，

especially that it is one of the very few that are available today for scaling.

尤其是它是其中一個少數 目前可擴大使用的方法

The technology is mature.

生物炭的技術成熟，

The scientific backing is here.

有科學上的論據，

The economics could work.

經濟效益上也可運作。

And the potential is huge.

也就潛力無窮。

In Africa alone,

僅計算非洲，

we estimate that half a billion tonnes of agricultural residues

我們估計農業剩餘就有五億噸

are available to produce biochar.

可以用來產製生物炭。

That means about the same amount of CO2

這也就表示有相同量體的二氧化碳

being removed every year from the atmosphere,

每年可自大氣中移除。

and there are many more billion tonnes in the rest of the world.

而且，世界上其他國家也有 超過好幾十億噸可用。

So let's make biochar a solution at scale.

所以，我們可以讓生物炭成為 大規模的解決方案。

For this, we need three things.

為了達成目標，我們需要做三件事:

One, access to biomass.

第一，取得生質物

Biochar production requires a large quantity of dry biomass,

生物炭的產製需要大量的乾燥生質物

ideally sourced close to the production facilities

理想的來源是靠近產製設施

to avoid transportation costs and emissions.

避免運輸過程產生的成本和碳排放。

It needs to be residual biomass

必須是殘餘的生質物，

so it does not require additional land to grow it.

因此不需要額外的土地種植它。

Most biochar companies today use wood residues,

現今 大部分生物炭的公司大多 使用木頭剩餘物，

like sawdust or branches,

例如鋸末、樹枝， 產製生物炭。

to produce biochar.

But many alternatives exists --

但仍有許多替代選擇，

in particular, agricultural residues.

尤其是，可用農業剩餘物，

Two, we need superefficient, 24-7 production systems.

第二，我們需要及高效率全天候產製系統。

The technology exists,

已經有這樣的技術，

but there's still room for improvement.

只是仍有改善的空間。

And three,

第三，

we need to encourage farmers to use biochar

我們須鼓勵農民使用生物炭。

so that they can reduce the usage of fertilizers,

這樣一來他們也可以減少肥料的使用，

and improve crop yields.

並改善作物產量。

Many companies, as we speak,

正如我們說的，有許多公司

are developing biochar-based business

正在開發生物炭的商業模式

in a variety of geographies and with a variety of feedstocks.

包括不同的地方區域， 以及使用不同的原料。

I cofounded one of them.

而我是這之中的一家公司共同創辦人。

We focus on tropical developing countries.

我們關注的是熱帶開發中國家，

Biomass is superabundant there,

這裡有非常豐富的生質物，

in the form of agricultural residues.

來自於農業剩餘物。

We used an optimized production model,

我們使用了優化的生產模式，

with easy-to-operate, midsize production plants,

搭配規模中等、容易操作的生產工廠。

where the pyrolysis reactor looks like a tank wagon.

工廠的熱裂解反應爐看起來像坦克車。

Soils in the tropics are generally poor and acidic,

熱帶地區的土壤通常很貧瘠和酸化的。

hence benefit the most from the addition of biochar.

利用生物炭的添加物帶來更明顯的效益。

And last,

最後，

energy generation is most needed in rural areas of developing countries,

能源生產是開發中國家鄉村地區的 重點需求。

where, very often, less than 25 percent of the people

在這些地方，經常僅有不到 25% 的人

have access to electricity.

可以使用電力。

That's how we go back to Mister [unclear].

讓我們講回伊萬納先生，

We will convert to biochar the leftovers from his coffee cherries

我們將咖啡果實的剩餘物轉為生物炭，

so that he can use it in his fields

讓他可以在他農地中使用，

to improve the quantity and quality of his production.

去改善作物生產的品質與產量。

Mr. Ewané will be able to afford the biochar,

伊萬納先生可以負擔的起生物炭，

given that it will be highly subsidized by the related carbon credits.

由於相關的碳權將提供高額補貼。

And the electricity generated will be distributed locally.

而發電也可以在地方上供應，

A very circular model,

一個完整的循環模型，

for climate and people,

用於氣候變遷和人類。

now.

現在

Thank you for your attention.

感謝您的聆聽。