演講MP3+雙語文稿:一種從大氣中去除二氧化碳的新方法

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聽力課堂TED音頻欄目主要包括TED演講的音頻MP3及中英雙語文稿，供各位英語愛好者學(xué)習(xí)使用。本文主要內(nèi)容為演講MP3+雙語文稿:一種從大氣中去除二氧化碳的新方法，希望你會喜歡！

【演講者及介紹】Jennifer Wilcox

化學(xué)工程師Jennifer Wilcox致力于測試和測量微量金屬和碳捕獲的方法，以減輕化石燃料對地球的影響。

【演講主題】一種從大氣中去除二氧化碳的新方法

【中英文字幕】

翻譯者Annie Zhang 校對者M(jìn)ark Huang

00:13

Four hundred parts per million: that's theapproximate concentration of CO2 in the air today. What does this even mean?For every 400 molecules of carbon dioxide, we have another million molecules ofoxygen and nitrogen. In this room today, there are about 1,800 of us. Imaginejust one of us was wearing a green shirt, and you're asked to find that singleperson. That's the challenge we're facing when capturing CO2 directly out ofthe air. Sounds pretty easy, pulling CO2 out of the air. It's actually really difficult.

百萬分之四百：這就是現(xiàn)在空氣里二氧化碳大概的濃度。這意味著什么呢？意味著每四百個二氧化碳分子，都混了另外一百萬個氧和氮分子。今天這個房間里大概有1800人。想象一下我們當(dāng)中只有一個人穿著綠色襯衫，而你被要求找到那個人。這就是我們從空氣中直接捕獲二氧化碳需要面臨的挑戰(zhàn)。把二氧化碳從空氣中提取出來，聽起來很簡單，但這實際上是個很復(fù)雜的過程。

00:53

But I'll tell you what is easy: avoidingCO2 emissions to begin with. But we're not doing that. So now what we have tothink about is going back; pulling CO2 back out of the air. Even though it'sdifficult, it's actually possible to do this. And I'm going to share with youtoday where this technology is at and where it just may be heading in the nearfuture.

但我要告訴你什么是簡單的：在源頭減少二氧化碳排放。但是我們并沒有真正這樣做。所以我們現(xiàn)在得考慮如何逆轉(zhuǎn)現(xiàn)狀；將二氧化碳從空氣中移除。雖然這個過程很困難，但是依然有可能實現(xiàn)。我今天將與你們分享用來移除二氧化碳的科技，以及在不久的將來，它會朝哪個方向發(fā)展。

01:20

Now, the earth naturally removes CO2 fromthe air by seawater, soils, plants and even rocks. And although engineers andscientists are doing the invaluable work to accelerate these natural processes,it simply won't be enough. The good news is, we have more. Thanks to humaningenuity, we have the technology today to remove CO2 out of the air using achemically manufactured approach. I like to think of this as a syntheticforest. There are two basic approaches to growing or building such a forest.One is using CO2-grabbing chemicals dissolved in water. Another is using solidmaterials with CO2-grabbing chemicals.

地球能夠自然地通過海水，泥土，草木甚至是石頭將二氧化碳從空氣中移除。盡管工程師和科學(xué)家們?yōu)榱思涌爝@個自然的過程做了許多寶貴的工作，但還遠(yuǎn)遠(yuǎn)不夠。好消息是，我們還有別的技術(shù)。感謝人類的聰明才智，我們今天才能擁有通過化學(xué)制造將二氧化碳從空氣中移除的科技。我把它稱為人工森林?？偟膩碚f，有兩種方法可以實現(xiàn)人工森林。一種是使用溶于水的二氧化碳捕集材料。另一種是使用固態(tài)的二氧化碳捕集材料。

02:14

This is called an air contactor. You cansee it has to be really, really wide in order to have a high enough surfacearea to process all of the air required, because remember, we're trying tocapture just 400 molecules out of a million. Using the liquid-based approach todo this, you take this high surface area packing material, you fill thecontactor with the packing material, you use pumps to distribute liquid acrossthe packing material, and you can use fans,to bubble the air through the liquid. The CO2 in the air is separated[by] the liquid by reacting with the really strong-binding CO2 molecules insolution. And in order to capture a lot of CO2, you have to make this contactordeeper. But there's an optimization, because the deeper you make thatcontactor, the more energy you're spending on bubbling all that air through. Soair contactors for direct air capture have this unique characteristic design,where they have this huge surface area, but a relatively thin thickness.

它被稱為空氣接觸器?？梢钥吹?，它必須設(shè)計得非常非常寬，這樣才能獲得足夠大的表面積來處理所有需要的空氣，請謹(jǐn)記，我們要嘗試在一百萬個分子之中捕獲僅僅四百個分子。若使用液體材料來捕獲二氧化碳，需要選用表面積大的填充材料，將空氣接觸器裝滿，再使用泵驅(qū)動，并確保液體在填充材料之間充分流動。然后你就可以使用風(fēng)扇，將空氣吹進(jìn)裝置，以氣泡的形態(tài)穿過液體?？諝庵械亩趸寂c液體材料發(fā)生反應(yīng)，從而將二氧化碳分子分離出來。為了能捕獲更多的二氧化碳，還必須將接觸器造得更深。但是這種提升并不是無限的，因為接觸器造得越深，制造氣泡所消耗的能量也越多。所以直接捕捉空氣的空氣接觸器就具備了這個獨一無二的設(shè)計，巨大的表面積和相對較薄的厚度。

03:26

And now once you've captured the CO2, youhave to be able to recycle that material that you used to capture it, over andover again. The scale of carbon capture is so enormous that the capture processmust be sustainable, and you can't use a material just once. And so recyclingthe material requires an enormous amount of heat, because think about it: CO2is so dilute in the air, that material is binding it really strong, and so youneed a lot of heat in order to recycle the material. And to recycle thematerial with that heat, what happens is that concentrated CO2 that you gotfrom dilute CO2 in the air is now released, and you produce high-purity CO2.And that's really important, because high-purity CO2 is easier to liquify,easier to transport, whether it's in a pipeline or a truck, or even easier touse directly, say, as a fuel or a chemical.

在二氧化碳被捕獲之后，我們還需要能夠循環(huán)使用用來捕獲它的材料，持續(xù)不斷進(jìn)行捕獲。畢竟，當(dāng)碳捕獲具備了龐大的規(guī)模，其捕獲方法必須能夠滿足長遠(yuǎn)需求并能重復(fù)利用材料。另外，重復(fù)利用材料的過程需要消耗大量的熱量，試想一下：二氧化碳在空氣中是如此稀薄，材料對它的約束力就會非常大，你需要消耗很多熱量才能回收這個材料。所以你消耗熱量回收材料時，從空氣中收集的濃縮二氧化碳將被釋放出來，你將得到高純度的二氧化碳。這一點很重要，因為高純度的二氧化碳更容易液化，無論是利用管道還是卡車，都比氣態(tài)二氧化碳更容易運輸，甚至更容易被直接使用，比如作為燃料或者化學(xué)品。

04:25

So I want to talk a little bit more aboutthat energy. The heat required to regenerate or recycle these materialsabsolutely dictates the energy and the subsequent cost of doing this. So I aska question: How much energy do you think it takes to remove a million tons ofCO2 from the air in a given year? The answer is: a power plant. It takes apower plant to capture CO2 directly from the air. Depending on which approachyou choose, the power plant could be on the order of 300 to 500 megawatts. Andyou have to be careful about what kind of power plant you choose. If you choosecoal, you end up emitting more CO2 than you capture.

關(guān)于能量，我想再多講一些。再生或者回收那些材料的熱量需求決定了這個過程需要的能量和附隨的成本。我想問一個問題：你覺得在一年內(nèi) 從空氣中移除一百萬噸的二氧化碳 需要多少能量？ 答案是： 一個發(fā)電廠。需要一個發(fā)電廠來提供從空氣中 捕獲二氧化碳所需要的能量。發(fā)電廠的發(fā)電量，取決于選擇的方法，可能在300到500兆瓦之間。還要謹(jǐn)慎選擇發(fā)電廠的燃料類別。如果選擇的是煤，產(chǎn)生的二氧化碳會比捕獲的還多。

05:14

Now let's talk about costs. Anenergy-intensive version of this technology could cost you as much as $1,000 aton just to capture it. Let's translate that. If you were to take that veryexpensive CO2 and convert it to a liquid fuel, that comes out to 50 dollars agallon. That's way too expensive; it's not feasible.

現(xiàn)在讓我們談?wù)劤杀締栴}。如果僅僅為了捕獲一噸二氧化碳而選擇在該技術(shù)上投入大量能源，其花費將多達(dá)一千美金。讓我們解釋一下這句話。如果你要把非常昂貴的二氧化碳轉(zhuǎn)化成液體燃料，燃料價格將會高達(dá)五十美元一加侖。這太貴了；完全是不可行的。

05:36

So how could we bring these costs down?That's, in part, the work that I do. There's a company today, acommercial-scale company, that can do this as low as 600 dollars a ton. Thereare several other companies that are developing technologies that can do thiseven cheaper than that. I'm going to talk to you a little bit about a few ofthese different companies.

那么我們要怎樣降低費用？這就是我所做的部分工作。當(dāng)前有一個公司，一個商業(yè)規(guī)模的公司，可以使費用降到每噸六百元。還有其他幾個開發(fā)技術(shù)的公司，還可以進(jìn)一步降低成本。我要向你們簡單介紹一下這些不同的公司。

05:58

One is called Carbon Engineering. They'rebased out of Canada. They use a liquid-based approach for separation combinedwith burning super-abundant, cheap natural gas to supply the heat required.They have a clever approach that allows them to co-capture the CO2 from the airand the CO2 that they generate from burning the natural gas. And so by doingthis, they offset excess pollution and they reduce costs.

其中一個叫做Carbon Engineering，位于加拿大。他們使用基于液體的分離方法結(jié)合過剩的，廉價的天然氣來提供所需要的熱量。他們發(fā)明了一個很巧妙的方法，可以從空氣中捕獲二氧化碳的同時，也捕獲燃燒天然氣產(chǎn)生的二氧化碳。這樣一來，他們就抵消了過度污染的影響，也降低了成本。

06:26

Switzerland-based Climeworks and US-basedGlobal Thermostat use a different approach. They use solid materials forcapture. Climeworks uses heat from the earth, or geothermal, or even excesssteam from other industrial processes to cut down on pollution and costs.Global Thermostat takes a different approach. They focus on the heat requiredand the speed in which it moves through the material so that they're able torelease and produce that CO2 at a really fast rate, which allows them to have amore compact design and overall cheaper costs.

位于瑞士的Climeworks 和位于美國的Global Thermostat 使用的則是不同的方法，固體材料捕獲。Climateworks 使用來自地球的熱量或者地?zé)崮?，甚至是來自其他工業(yè)過程的過量蒸汽來減少污染和降低費用。Global Thermostat則另辟蹊徑，他們專注于所需的熱量以及它穿過材料的速度，于是就可以在一個很快的速率下釋放和生產(chǎn)二氧化碳，這使得他們采用了更密致的設(shè)計，以及整體上更低廉的費用。

07:07

And there's more still. A synthetic foresthas a significant advantage over a real forest: size. The Amazon is capable of capturing 1.6billion tons of CO2 each year. This is the equivalent of roughly 25 percent ofour annual emissions in the US. The land area required for a synthetic forestor a manufactured direct air capture plant to capture the same is 500 timessmaller. In addition, for a synthetic forest, you don't have to build it on arableland, so there's no competition with farmland or food, and there's also noreason to have to cut down any real trees to do this.

還有很多這樣的例子。人造森林與天然森林相比有一個顯著的優(yōu)勢：規(guī)模。亞馬遜地區(qū)每年能捕獲 16億噸的二氧化碳。大約等于美國每年排放量的百分之二十五。而要捕獲等量的二氧化碳所需的人工森林或者人造空氣捕獲工廠，其占地面積只有天然森林的五百分之一。另外，人工森林不需要在耕地上建造，所以并不會占用畜牧和農(nóng)耕土地，而且我們也不需要砍去任何自然生長的樹木來建造人工森林。

07:59

I want to step back, and I want to bring upthe concept of negative emissions again. Negative emissions require that theCO2 separated be permanently removed from the atmosphere forever, which meansputting it back underground, where it came from in the first place. But let'sface it, nobody gets paid to do that today -- at least not enough. So thecompanies that are developing these technologies are actually interested in takingthe CO2 and making something useful out of it, a marketable product. It couldbe liquid fuels, plastics or even synthetic gravel. And don't get me wrong --these carbon markets are great. But I also don't want you to be disillusioned.These are not large enough to solve our climate crisis, and so what we need todo is we need to actually think about what it could take.

我想退一步，再次提出負(fù)排放的概念。負(fù)排放，需要被分離的二氧化碳永久性地從大氣層中去除，這意味著把它送回地下，也就是它最初所在的地方。但請讓我們面對現(xiàn)實吧，至今都沒有人以此為生——至少相關(guān)從業(yè)者數(shù)量還遠(yuǎn)遠(yuǎn)不夠。所以開發(fā)這些技術(shù)的公司其實是對獲取二氧化碳感興趣，為了從中造出有價值的東西，一個可銷售的產(chǎn)品。它可以是液體燃料，塑料，甚至是合成的礫石。別誤會我的意思——這些碳源的市場非常好。但是我也不想讓你們產(chǎn)生錯誤的幻想。這些市場還不夠大，不足以解決氣候危機，所以我們需要認(rèn)真思考一下還能做些什么來解決危機。

08:55

One thing I'll absolutely say is positiveabout the carbon markets is that they allow for new capture plants to be built,and with every capture plant built, we learn more. And when we learn more, wehave an opportunity to bring costs down. But we also need to be willing toinvest as a global society. We could have all of the clever thinking andtechnology in the world, but it's not going to be enough in order for thistechnology to have a significant impact on climate. We really need regulation,we need subsidies, taxes on carbon. There are a few of us that would absolutelybe willing to pay more, but what will be required is for carbon-neutral,carbon-negative paths to be affordable for the majority of society in order toimpact climate.

關(guān)于碳市場的一個絕佳的事實就是，它至少支撐了建造新的捕獲工廠，每建造一個捕獲工廠，我們都會學(xué)到更多；當(dāng)我們學(xué)到更多，我們就能不斷地降低成本。但作為一個國際社會，我們還需要愿意去投資。我們有世界上所有的奇妙思想和科技，但是這還遠(yuǎn)無法讓這項技術(shù)對氣候帶來顯著的改善。我們還切實地需要法規(guī)扶持，我們需要補貼，碳稅，我們當(dāng)中有一部分人絕對愿意為此花更多的錢，但為了走向零碳排放，甚至是碳負(fù)排放的道路，我們需要讓社會中的大多數(shù)人都能夠承擔(dān)得起這部分費用，才能真正影響氣候。

09:50

In addition to those kinds of investments,we also need investments in research and development. So what might that look like?In 1966, the US invested about a half a percent of gross domestic product inthe Apollo program. It got people safely to the moon and back to the earth.Half a percent of GDP today is about 100 billion dollars. So knowing thatdirect air capture is one front in our fight against climate change, imaginethat we could invest 20 percent, 20 billion dollars. Further, let's imaginethat we could get the costs down to a 100 dollars a ton. That's going to behard, but it's part of what makes my job fun.

除了這些投資，我們還需要人們在研發(fā)項目中投資。這意味著什么呢？ 1966年，美國百分之五十的GDP 被用于投資阿波羅計劃。該計劃幫助人類安全地登上了月球，并順利返回地球。而在今天，一半的GDP 大概是一千億美金。所以當(dāng)知道直接捕獲空氣和與氣候變化做斗爭是同一個戰(zhàn)線后，想象一下我們能夠投資 20%的GDP，兩百億美元。更進(jìn)一步，讓我們設(shè)想一下降低成本到100美金一噸。這很困難，但也正是我工作中的樂趣所在。

10:36

And so what does that look like, 20 billiondollars,100 dollars a ton? That requires us to build 200 synthetic forests,each capable of capturing a million tons of CO2 per year. That adds up to aboutfive percent of US annual emissions. It doesn't sound like much. Turns out,it's actually significant. If you look at the emissions associated withlong-haul trucking and commercial aircraft, they add up to about five percent.Our dependence on liquid fuels makes these emissions really difficult to avoid.So this investment could absolutely be significant.

兩百億美金，一百美金一噸，是個什么概念呢？這需要我們建造二百個人工森林，每個人工森林一年能捕獲一百萬噸的二氧化碳。這加起來相當(dāng)于美國每年碳排放量的百分之五。聽起來好像不多。實際上，效果已經(jīng)相當(dāng)明顯了。如果你查看長途運輸和商用飛機產(chǎn)生的碳排放，其合計總量就達(dá)到了百分之五左右。我們對液體燃料的依賴使這樣的碳排放量非常難以避免。所以毋庸置疑，這項研究意義重大。

11:18

Now, what would it take in terms of landarea to do this, 200 plants? It turns out that they would take up about halfthe land area of Vancouver. That's if they were fueled by natural gas. Butremember the downside of natural gas -- it also emits CO2. So if you usenatural gas to do direct air capture, you only end up capturing about a thirdof what's intended, unless you have that clever approach of co-capture thatCarbon Engineering does. And so if we had an alternative approach and used windor solar to do this, the land area would be about 15 times larger, looking atthe state of New Jersey now. One of the things that I think about in my workand my research is optimizing and figuring out where we should put these plantsand think about the local resources available -- whether it's land, water,cheap and clean electricity -- because, for instance, you can use cleanelectricity to split water to produce hydrogen, which is an excellent,carbon-free replacement for natural gas, to supply the heat required.

11:17

那么要建造200個工廠，需要多少土地呢？事實上，它們將占據(jù)溫哥華大約一半的土地面積。這還是在利用天然氣作為燃料的前提下。但是別忘了天然氣的缺點——燃燒時也會排放二氧化碳。所以如果你使用天然氣直接捕獲空氣，你最終只會捕獲到預(yù)期量的三分之一，除非你有像Carbon Engineering一樣同時捕獲兩者的方法。如果我們有一個替代的方法，使用風(fēng)力發(fā)電或者太陽能發(fā)電，但隨之所需的土地面積可能會擴大十五倍，和現(xiàn)在的新澤西州一樣大。我在工作和研究時經(jīng)常思考的一件事，就是優(yōu)化和解決兩個問題，將這些工廠放在哪里，以及如何就地取材——是否有足夠的土地面積，水資源，廉價和無污染的電能——因為，例如無污染的電能可以把水分解成氫氣，這是一個極好的，無碳的天然氣替代品，可以提供所需的熱量。

12:22

But I want us to reflect a little bit againon negative emissions. Negative emissions should not be considered a silverbullet, but they may help us if we continue to stall at cutting down on CO2pollution worldwide. But that's also why we have to be careful. This approachis so alluring that it can even be risky, as some may cling onto it as somekind of total solution to our climate crisis. It may tempt people to continue toburn fossil fuels 24 hours a day, 365 days a year. I argue that we should notsee negative emissions as a replacement for stopping pollution, but rather, asan addition to an existing portfolio that includes everything, from increasedenergy efficiency to low-energy carbon to improved farming -- will allcollectively get us on a path to net-zero emissions one day.

但是我想提醒大家再次對負(fù)排放進(jìn)行反思。負(fù)排放不應(yīng)該被當(dāng)作是萬全之策，但是它們可以在實現(xiàn)真正減少全球二氧化碳排放前幫我們爭取一些時間。這也是為什么我們必須小心謹(jǐn)慎。這個方法是如此的誘人，甚至?xí)a(chǎn)生負(fù)面效應(yīng)，有些人過分依賴它，把它看作能徹底解決氣候危機的方案。它可以誘使人們每年365天，每天24小時，繼續(xù)燃燒化石燃料。我認(rèn)為我們不應(yīng)該把負(fù)排放當(dāng)成中斷污染的替代品，相反的，應(yīng)該把它當(dāng)成現(xiàn)有的改善環(huán)境措施的一個附加品，從提高能源效率到低碳排放，再到優(yōu)化農(nóng)業(yè)——總有一天，會讓我們走上一條零碳排放的道路。

13:18

A little bit of self-reflection: my husbandis an emergency physician. And I find myself amazed by the lifesaving work thathe and his colleagues do each and every day. Yet when I talk to them about mywork on carbon capture, I find that they're equally amazed, and that's becausecombatting climate change by capturing carbon isn't just about saving a polarbear or a glacier. It's about saving human lives.

我還想談?wù)勛约旱囊稽c反思：我的丈夫是一位急診醫(yī)師。他和同事每天從事的救死扶傷的工作令我大為驚嘆。然而當(dāng)我和他們談起我與碳捕獲相關(guān)的工作，他們也同樣表示了贊嘆，因為通過捕獲碳來對抗氣候變化并不只是關(guān)于拯救北極熊或者防止冰川融化，這是為了拯救人類。

13:50

A synthetic forest may not ever be aspretty as a real one, but it could just enable us to preserve not only theAmazon, but all of the people that we love and cherish, as well as all of ourfuture generations and modern civilization.

人工森林可能沒有天然森林的美觀，但是它不僅僅讓我們保護有能力亞馬遜，還能保護所有我們所愛的和珍惜的人，以及所有的子孫后代和現(xiàn)代文明。

14:09

Thank you.

謝謝。

14:10

(Applause)

（掌聲）