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  • The Earth's climate is shifting, and it's our fault.


  • Not Seeker, specifically, I mean humans in general.

    並不是特別指 Seeker 的錯,一般來說,我是指全人類。

  • We're digging up and burning sources of carbon that otherwise would have been locked


  • away within the Earth, adding it to our atmosphere and driving average global temperatures up.


  • So why don't we take the carbon from the air, and push it somewhere else?


  • That's the idea behind Negative Emission Technologies, or NETs.

    這就是負排放技術 (NETs) 背後的想法。

  • They're one possible tool to stop climate change, but they aren't the silver bullet.


  • It's tempting to think that if we develop a way to scrub the air of CO2 we won't have to cut down our emissions so much.


  • No lifestyle change, no big shift in energy infrastructure, just some quick fix that keeps this climate change thing from getting out of hand.


  • Unfortunately while that's theoretically possible it's very far from practical.


  • At the start of 2018 the European Academies Science Advisory Council released a report

    2018 年初,歐盟科學顧問委員會發表一份報告,

  • on how feasible NETs are for slowing or reversing the effects of atmospheric carbon dioxide and their conclusion isnot good.

    針對 NETs 能否減緩或徹底改變大氣中二氧化碳的可行性,他們的結論是......不太行。

  • First it helps to understand why plucking CO2 from thin air isn't as easy as it sounds.


  • As of 2013 we were adding an estimated 40 billion tons of CO2 to the air annually.

    從 2013 年起,我們每年在空氣中增加約 400 億噸的二氧化碳。

  • While that's a lot of CO2, it's not very concentrated; there are only about 400 CO2 molecules per million molecules that make up our air.

    雖然二氧化碳的量很多,但並沒有很集中;每百萬分子中,約只有 400 個二氧化碳分子構成我們的空氣。

  • So if you want to just neutralize the stuff we're putting out each year, you're going to have to churn through a lot of air.


  • Jennifer Wilcox, an assistant professor at Stanford University, imagines what she calls a synthetic forest.


  • Sounds like cool funky neon trees but really it's more a 200 meter wall of fans pushing air through liquid with chemicals that capture carbon dioxide.

    聽起來像是很酷又時髦的霓虹燈樹,但實際上是個 200 公尺的壁扇,推動空氣穿過液體時,化學物質會捕獲二氧化碳。

  • The chemical is then separated from the CO2 using high heat, allowing it to go back and capture more carbon.


  • What's left behind is high-purity CO2 that's easier to liquify or repurpose.


  • Now you may have noticed this process isn't passive, you need to put energy into it.


  • Wilcox estimates that to remove a million tons of CO2 a year,

    威爾考克斯估計,每年要減少 100 萬噸二氧化碳,

  • you'd need a dedicated power plant putting out anywhere from 300 to 500 megawatts.

    需要一個專用發電廠,發電量在 300 到 500 百萬瓦之間。

  • So to balance out that 40 billion tons we're emitting annually, that works out to 40,000 additional power plants.

    因此,為了要平衡每年排放的 400 億噸二氧化碳,發電廠將增加額外 40,000 座。

  • And that's assuming you use carbon neutral power.


  • If you use a coal plant, you emit more than you extract.


  • A synthetic forest isn't the only possible negative emission technology.


  • We could go au naturale and plant more forests.


  • Let the trees do the work.


  • Except planting new forests is hard and we're already deforesting what currently exists.


  • Really it'd be better to get that under control first.


  • Another alternative is sprinkling iron into the ocean, stimulating photosynthetic plankton to absorb more CO2.


  • But that process is kind of like unleashing a tiger and hoping it takes care of your gorilla problem.


  • We could try making a carbon capturing mineral like magnesite in a lab.


  • The mineral forms when magnesium is introduced to carbonic acid, a molecule that results when CO2 and water react.


  • In August of 2018 scientists discovered how to make it artificially in just 72 days,

    2018 年 8 月,科學家發現如何在 72 天人為製造出菱鎂礦,

  • as opposed to the hundreds of thousands of years it takes to form naturally.


  • Now we just need to make 80 billion tons of the stuff every year and we're set.

    我們現在每年只需生產 800 億噸的東西,我們就搞定了。

  • All of these issues led the European Academies Science Advisory Council to conclude that betting on NETs alone is not the answer.

    這些問題導致歐盟科學顧問委員會得出一個結論,就是僅僅賭在 NETs 上並不是正解。

  • We can't keep emitting at the rate we are now and hope some future carbon capture wonder tech will turn the tide.


  • The goal is still to cut current emissions as drastically as possible.


  • In the meantime we can still develop negative emission technologies.


  • Just because they can't stop climate change alone doesn't mean they can't help.


  • But humans need to scale back our carbon emission so NETs don't have to counter 40 billion tons of CO2 every year.

    但人類需要縮減碳排放量,這樣 NETs 每年就不必抵銷 400 億噸的二氧化碳。

  • While you're here subscribe for more videos, and check out Marens video about new solar technology powered by bacteria.

    在你訂閱看到更多影片的同時,來看看 Marens 的影片,了解由細菌驅動的新太陽能技術。

  • While CO2 levels are at 400 parts per million today, until 1950 CO2 hadn't risen above 300 parts per million for over 400 thousand years.

    雖然二氧化碳含量目前為百萬分之 400,但直到 1950 年,二氧化碳濃度在 40 多萬年中,從未超過百萬分之 300。

  • Thanks for watching and I'll see you next time on Seeker!

    謝謝觀看,下次在 Seeker 的影片見!

The Earth's climate is shifting, and it's our fault.



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