Decades of heatwaves and droughts  have led to unusually poor harvests,  

幾十年來的熱浪及乾旱帶來不尋常的欠收, 暖化的海洋也造成漁獲的銳減

while the warming oceans yield fewer fish each  year. In the tropical zones, millions suffer from  

在熱帶地區, 百萬計的人深受飢荒以及資源戰爭所苦, 並向北方逃難

famine and resource wars have made millions  more flee to the north. As things quickly  

事態急轉直下, 世界各國也政府只能無奈制定應急計劃...

get worse, in an act of desperation, the world's  governments decide to enact an emergency plan...

雖然未來是否會如此的嚴峻依舊有待商榷

It is far from certain that a grim scenario like  this will play out. But the failure of world  

但世界的領導者們對於氣候變遷的應對失利, 讓這一切變得很有可能

leaders to effectively address climate  change, makes it far from impossible.

所以不遠的未來, 或許有必要執行一些激進的手段來減緩氣候變遷, 像是：地理工程學

So in the near future it might become necessary  to try something radical to slow down rapid  

它的規模之大, 有可能會抵銷人類幾世紀帶來的改變

climate change: Geoengineering.  Interventions so massive in scale  

或使這一切更加惡化

that they might undo centuries of human  behavior. Or make everything much worse.

什麼是地理工程學？

What is geoengineering, is it really  an option and what if it goes wrong?

他真的是一個有效的做法嗎？有沒有可能變得更糟？

Geoengineering methods vary from fantastic ones  like constructing giant light sails in space  

[好聽的開場音樂]

to seeding clouds with salt or  wilder ones like fertilizing  

地理工程學提供許多想法, 有的像是在太空架巨型陽傘或是用鹽促進雲層產生一樣天馬行空

the oceans with iron to speed up the  growth of trillions of algae cells.

也有瘋狂的像是用鐵來為海洋「施肥」，以加速數萬億藻類細胞的生長

In this video we’ll focus on an intervention  we could see during our lifetimes:  

在這部影片中, 我們會只討論我們這個世代能夠做得到的方法

Stratospheric aerosol injection. A clunky term  

平流層氣溶膠注入氣候工程

that means spraying stuff very high up  in the atmosphere to keep the sun away.

這個撓口的學術名詞是指在大氣層中極高的位置噴灑東西來減少日照

Keeping the Sun away

日射をさえぎる Keeping the Sun away 「減少日照」

CO2 doesn’t heat up the planet on its own, almost  all of the energy on earth comes from the sun in  

二氧化碳並不是靠自己加熱地球, 大部分的能量都是來自於太陽的電磁輻射熱

the form of electromagnetic radiation. About 71%  of this energy is absorbed by the earth's surface  

大約有71%的能量會被地表以及大氣層吸收

and atmosphere. This absorbed energy is  emitted again, as infrared radiation. And  

被吸收的能量會以紅外線的形式再次被釋放出來

CO2 is able to trap this infrared radiation  and keep it in the atmosphere for a while.  

而二氧化碳能夠把紅外線拘留在大氣中, 讓它停留一段時間

You can compare this effect with  snuggling under a blanket in the morning.  

你可以把這個現象類比成, 早上躲在被窩裡的感覺

Even in a really cold room, your  body emits infrared radiation  

就算在一個非常寒冷的房間裡, 你的身體還是不斷釋放著紅外線

and the air between your body and the blanket  traps it and creates a warm and comfy feeling.

而它們也被你的身體與棉被之間的空氣留住, 產生了溫暖舒服的感覺

So one way to cool down the planet would  be to prevent energy from getting trapped  

所以讓地球變得涼快的方式之一, 是阻止能量在我們的星球大毛毯之下被抓住

under our planet blanket. Which is  already happening naturally. About 29%  

而這其實已經不斷在自然界中發生

of the solar radiation hitting earth  is reflected back to space by bright  

大約29%的太陽輻射在到達地球後被反射回太空

surfaces like ice, deserts, snow or clouds.  More reflection, less energy, less warming.

透過像是冰, 沙漠, 雪還有雲之類的光滑表面

We can look at nature for inspiration:

越多反射, 越少能量, 氣溫也逐步降低

Specifically the 1991 Mount Pinatubo  eruption, the second largest volcanic  

可以看看大自然為我們帶來的啟發:

eruption of the 20th century. Aside from  massive devastation and almost 900 dead,  

特別是1991年的皮納土波火山爆發

scientists noted its strong impact on the  global climate. The explosion ejected millions  

是為20世紀第二大的火山噴發

of tons of particles and gas as high as the  stratosphere which hung around there for a while.

除了大規模破壞和近900人死亡之外，科學家還注意到它對全球氣候的強烈影響

The stuff that is interesting for geoengineering  is sulphur dioxide. A nasty smelling and invisible  

爆炸噴射出數百萬噸粒子和氣體，其高度與懸在那裡的平流層不分伯仲

gas. High in the atmosphere, it produced a haze  of sulfuric acid droplets, that mixed with water  

並且滯留了好一段時間

and created giant veils. These veils reduced the  sunlight reaching earth’s surface by roughly 1%.  

而真正令地理工程學感興趣的是二氧化硫

Global average temperatures dropped by 0.5°C.  

一種帶有難聞氣味又不能被肉眼所見的氣體

It took three years until this  cooling effect had stopped.

在大氣層高處，水與硫酸液的薄霧形成巨大的面紗

Humans could imitate this process by injecting  sulfur particles directly into the stratosphere.  

這層面紗為地面減少了大約1%的陽光

According to some scientists, this  might be surprisingly easy to do  

全球均溫也下降了約0.5°C

and we don’t even need a lot of new  technology for it. According to one study,  

而3年過後才停止了這個冷卻的效果

it also might be pretty cheap compared  with the cost of rapid climate change.

人類可以通過將硫顆粒直接注入平流層來有樣學樣

A small fleet of specialized airplanes could  ascend once a year and distribute aerosols along  

一些科學家表示, 這可能會出人意料地簡單

the equator from where they would be spread around  the world. Projections assume that injecting  

甚至不需要使用太多新的技術就能做到

between five and eight megatons of material per  year would reflect enough sunlight to slow down  

根據一項研究指出, 跟劇烈的氣候變遷相比, 可說是價格低廉

or even stop global warming. . Giving us precious  time to transition away from fossil fuels.

只要一小群專門的飛機每年升空一次

Unfortunately, there might be  a few unhappy side effects.

並沿著赤道散佈氣溶膠，它們將從那裡擴散到世界各地

There are a number of potential  issues with aerosol injections:  

預估每年注入約5到8兆噸就能發揮功效

rainfall patterns could change which  could negatively affect agriculture  

來反射足夠多的陽光來減緩, 甚至是停止全球暖化

and cause famine. Billions of people  could be affected in the worst case.

並為我們淘汰化石燃料的過渡期提供了寶貴的時間

Also, after the 1991 Mount Pinatubo eruption, the  acid/water veils not only cooled down the surface,  

但不幸的是, 那可能會造成一些不太妙的副作用

they also heated up the  stratosphere. As it turns out,  

氣溶膠注入有許多潛在問題:

acid is bad for the ozone layer and the  ozone hole over Antarctica was the largest  

降雨模式可能會發生變化，從而對農業產生負面影響並導致飢荒

it ever has been . Injecting sulfur particles  over decades could have a similar effect.

最糟的情況下, 幾十億人會受此牽連

Scientists have already suggested  using a combination of different  

此外, 1991年的皮納土波火山爆發後

minerals that might have much less  harmful effects on the ozone layer  

那層酸液構成的面紗不只冷卻了地表, 同時也加熱了平流層

but more research and experiments need  to be done to make sure this could work.

結果, 酸性物質對臭氧層有害，有史以來最大的臭氧洞就在南極上空誕生

But even if we don’t damage the  ozone layer, there are other risks.

幾十年來注入硫粒子可能會重蹈覆徹

Politicians and industry  might use the cooling effect  

有科學家建議使用混合不同物質的方式來減低對臭氧層的危害

as an excuse to delay the switch  to a carbon neutral economy.

但我們需要更多的研究及實驗來確保這個方法確實能奏效

Even if geoengineering slows down global  warming, humanity is still adding extra CO2  

然而即便能確保臭氧層安然無恙, 依舊純在其他風險

to the atmosphere. More CO2 in the air means  that the oceans absorb more CO2, which makes  

政治家和工業界可能會以冷卻效應為藉口推遲向碳中和經濟的轉變

them more acidic. This is already beginning to  be deadly to huge ecosystems like coral reefs.  

即便地理工程學減緩了全球暖化, 人類依舊釋放更多的二氧化碳到大氣中

And the longer this continues, the  more severe the effects will be.

空氣中存在更多二氧化碳, 就代表海水會因為吸收二氧化碳更加酸化

But it gets worse: Once we start pumping  particles into the atmosphere on a massive scale,  

這已經開始對珊瑚礁等巨大的生態系造成致命的影響

we might be forced to do so for a long  time, or we could risk a termination shock.

而只要這持續得越久, 事態也愈發嚴峻

What that means is that if humanity  continues to enrich the atmosphere with CO2,  

但更糟的還在後頭, 只要開始大規模釋放這些粒子到大氣中

but at the same time prevents the planet  from heating up by blocking solar radiation,  

我們會被迫長時間使用這個方法, 否則將遭遇嚴重的「終止衝擊」

we are sitting on a time bomb.

意思是說, 只要人類不斷讓大氣中充斥二氧化碳

Once we stop geoengineering, the  natural cycle will take over again,  

同時試圖仰賴阻擋陽光來防止全球暖化

and earth would heat up. But after a few  decades of keeping the planet artificially  

那我們就像是被綁了個定時炸彈一般如履薄冰

cold while still releasing massive amounts of  CO2, it would heat up, much, much quicker. An  

一旦結束地理工程, 大自然的循環將繼續接手進行暖化作用

increase in temperature that would take 50  years today, could happen in just 10 years.

但是在人為地球保持涼爽的同時, 持續排放大量二氧化碳的幾十年後

Such a temperature shock in such  a short time would disrupt every  

這次的暖化將會進行得非常, 非常的快

major system on earth so much that it  would be impossible to adapt in time.  

一個在現今需要50年才足以發生的轉變, 將會在短短10年就產生

The worst case scenario could be dramatic  famines and the rapid destruction of ecosystems.

如此短時間內出現的衝擊

Humanity might survive. But the survivors would inhabit an unfamiliar and hostile world.

會破壞每個地球上根本還不能夠及時適應的主要系統

The best case scenario is that once the world has  finally fully understood the existential danger  

最雪上加霜的可能是劇烈的饑荒還有對生態系的急遽破壞

of rapid climate change,geoengineering  can buy us a crucial decade or two.  

人類或許還能夠苟延殘喘, 但活下來的人們只能棲身於一個陌生且充斥著敵意的世界

Time to transition our economies  and maybe even pull CO2 out of the  

最理想的情況是, 全世界都意識到劇烈的氣候變遷與我們的存續息息相關

atmosphere. Maybe with technologies  that we’ll discuss in a future video.

地理工程學就能為我們換到10~20年的時間

# Conclusion

這些時間能用來轉型經濟或甚至把CO2排放到大氣層之外

Geoengineering is a scary concept. It is not a  solution to climate change and it might even be  

也許以後我們會有更多的影片來討論更多科技及技術層面的事

a welcome excuse for the fossil fuel industry  to delay the end of the fossil fuel age.

# 總結

Over the last few decades geoengineering has  been so controversial that it stopped many  

地理工程學是一個駭人聽聞的想法

scientists from doing the experiments  necessary to understand it better.  

它並不是對於氣候變遷的解決之道

But blankly opposing  geoengineering is short sighted.

還可能給了良好的藉口給化石燃料業者, 好來推延我們終結化石燃料世代的時間

The sad truth is that we are already  running a geoengineering experiment.  

在這幾十年內, 地理工程學爭議不斷

We are testing how fast the world changes if  we add about 40 billion tons of CO2 each year.  

以致於許多科學家中斷了必要的實驗也沒有充分地去理解它

This experiment is about to get really exciting.

但我們也不該短視的看到地理工程學就拒之於門外

Hopefully we never have to use Geoengineering.  But if we need to in the future,  

令人沮喪的事實是, 我們已經開始進行地理工程學的實驗

we better have done the science. We better  be prepared. Or a panicking humanity  

我們測試如果每年約排放400億噸的二氧化碳, 世界會以多快的速度改變

might accidentally press the self destruct button.

而這場實驗即將迎來最高潮

You probably won’t have to do any of that  yourself – but who knows! Better brush up  

希望我們永遠不必使用地理工程

on your science knowledge, just in case. Our  friends from Brilliant can help you with that.

而萬一我們在未來需要它的幫助

Brilliant is a problem-solving website and app  that makes science accessible in a practical  

最好確定已經完成了各項科學研究及實驗

way – more than 60 interactive courses give  you the tools to crack problems in math,  

有備才能無患

logic and engineering all by yourself.  Instead of a classic lecture format  

否則手足無措的人類隨時都可能不小心觸動了自毀按鈕

Brilliant uses story-telling,  code-writing and hands-on problems  

你或許不需要自己做任何事情 - 但誰知道呢!

to keep you entertained and engaged.  This way a small daily challenge can  

最好翻新翻新你的科學知識, 以防萬一! 而我們Brilliant的朋友可以幫助你

build up to real long-term understanding  of science and achieving your STEM goals.

Brilliant 是一個提供問題解決方式的網站, 同時也有APP讓科學變得能「隨身攜帶」

In a nutshell, Brilliant surprises you and  keeps you on your toes, all while sneaking  

超過60個互動課程讓你有工具來自己解決

some knowledge into your head without your  really noticing – right up our alley, really.

數學, 邏輯, 或各種工程上的難題

To get a fresh perspective on science, go to  Brilliant.org/Nutshell and sign up free.  

Brilliant 使用講故事、直接現寫程式碼和手把手教學，而不是經典的講座形式來激發你的興趣跟熱忱

And there’s an extra perk for kurzgesagt viewers:  

一個每日的挑戰也能建立真正長效的科普理解

the first 200people to use the link  get 20% off their annual membership,  

幫助你達成跨領域學習的目標

which lets you view all the daily problems  in the archives and unlock every course.

總之，Brilliant 給你帶來驚喜，讓你保持警覺

Brillant helps you end your day  a little smarter – still the  

一直在不知不覺中將一些知識潛入您的腦海中--就像被趕進了我們的小巷裡，真的

best preparation for the future we can think of.

趕快到Brilliant.org/Nutshell然後註冊一個免費的帳號, 開始用全新的角度對待科學