[A provocation from Danny Hillis:]
【丹尼 • 希利斯的挑釁:】
[It's time to start talking about engineering our climate]
【是開始談處理氣候議題的時候了】
What if there was a way to build a thermostat that allowed you to turn down the temperature of the earth anytime you wanted? Now, you would think if somebody had a plausible idea about how to do that, everybody would be very excited about it, and there would be lots of research on how to do it. But in fact, a lot of people do understand how to do that. But there's not much support for research in this area. And I think part of it is because there are some real misunderstandings about it. So I'm not going to try to convince you today that this is a good idea. But I am going to try to get your curiosity going about it and clear up some of the misunderstandings.
如果有辦法打造一個自動調溫器, 讓你可以隨時隨地 調降地球的溫度? 若有人有可行的想法, 每個人應該都會感到非常興奮, 而且會有很多相關的研究報告才對。 事實上,許多人確實知道要如何做。 但是,這個領域並沒有得到很多 相關研究的支持。 我認為部分原因, 是大家對它存在著一些誤解。 今天,我不會試著說服 各位相信這是個好點子。 但我會試著讓各位對它感到好奇, 同時也澄清一些誤解。
So, the basic idea of solar geoengineering is that we can cool things down just by reflecting a little bit more sunlight back into space. And ideas about how to do this have been around literally for decades. Clouds are a great way to do that, these low-lying clouds. Everybody knows it's cooler under a cloud. I like this cloud because it has exactly the same water content as the transparent air around it. And it just shows that even a little bit of a change in the flow of the air can cause a cloud to form. We make artificial clouds all the time. These are contrails, which are artificial water clouds that are made by the passing of a jet engine. And so, we're already changing the clouds on earth. By accident. Or, if you like to believe it, by supersecret government conspiracy.
太陽能地球工程的基本想法是, 只要把稍微多一點的太陽光 反射回太空, 我們就能將地球降溫。 數十年來人們探究要如何實踐。 雲會是很棒的方法,這些低空的雲。 大家都知道,在雲底下比較涼爽。 我喜歡這種雲,因為它的水含量 和周圍的透明空氣一樣。 這意味著即使空氣的流動 只有一丁點的改變, 就能形成雲。 我們一直都在製造人造雲。 這些是凝結尾,也就是人造水雲, 是噴射機引擎在飛行時所產生的。 我們已經在改變地球上的雲了。 非特意的。 或是,也有人相信 是政府的超神秘陰謀。
(Laughter)
(笑聲)
But we are already doing this quite a lot. This is a NASA picture of shipping lanes. Passing ships actually cause clouds to form, and this is a big enough effect that it actually helps reduce global warming already by about a degree. So we already are doing solar engineering. There's lots of ideas about how to do this. People have looked at everything, from building giant parasols out into space to fizzing bubble waters in the ocean. And some of these are actually very plausible ideas. One that was published recently by David Keith at Harvard is to take chalk and put dust up into the stratosphere, where it reflects off sunlight. And that's a really neat idea, because chalk is one of the most common minerals on earth, and it's very safe -- it's so safe, we put it into baby food. And basically, if you throw chalk up into the stratosphere, it comes down in a couple of years all by itself, dissolved in rainwater. Now, before you start worrying about all this chalk in your rainwater, let me explain to you how little of it it actually takes. And that turns out to be very easy to calculate. This is a back-of-the-envelope calculation I made.
但,我們已經常常在製造雲了。 這是太空總署拍的海上航道照片。 航行的船隻會導致雲的形成, 這影響夠大, 實際上已經有助於 減輕全球暖化大約一度。 所以我們已經在做太陽能工程了。 要如何去實踐它的點子有很多。 人們的想法應有盡有, 從在外太空建造巨型陽傘, 到使海水產生氣泡都有。 當中有一些想法似乎是蠻合理的。 近期,哈佛的大衛 • 凱斯 在刊物中提出了一個想法, 把白堊(粉筆)的粉末 投放到同溫層當中, 它會把太陽光反射回去。 那是很棒的想法, 因為白堊是地球上 最常見的礦物之一, 且它非常安全──安全到 我們會把它放到嬰兒食物中。 基本上,若你把白堊放到同溫層中, 幾年後它自己會落下, 在雨水中分解。 在各位開始擔心雨水中的白堊之前, 先讓我解釋需要使用的量有多麼少。 結果發現,這用量很容易計算。 這是我在信封背後做的計算。
(Laughter)
(笑聲)
(Applause)
(掌聲)
I assure you, people have done much more careful calculations, and it comes out with the same answer, which is that you have to put chalk up at the rate of about 10 teragrams a year to undo the effects of the CO2 that we've already done -- just in terms of temperature, not all the effects, but the temperature. So what does that look like? I can't visualize 10 teragrams per year. So I asked the Cambridge Fire Department and Taylor Milsal to lend me a hand. This is a hose pumping water at 10 teragrams a year. And that is how much you would have to pump into the stratosphere to cool the earth back down to pre-industrial levels. And it's amazingly little; it's like one hose for the entire earth. Now of course, you wouldn't really use a hose, you'd fly it up in airplanes or something like that. But it's so little, it would be like putting a handful of chalk into every Olympic swimming pool full of rain. It's almost nothing.
我向各位保證, 有人做過更精密的計算, 結果答案是相同的, 答案是,你需要每年放上 大約一千萬公噸的白堊, 來弭平二氧化碳已經造成的效應── 只有溫度上的效應, 不是所有的效應,僅限於溫度。 所以,那看起來是什麼樣子? 我無法具像化 每年一千萬公噸的樣子。 所以,我請劍橋消防局 和泰勒 • 米爾索 來幫我一個忙。 這水管灌注出的水量, 就是一年一千萬公噸。 只要把這麼多的量 灌注到同溫層, 就能讓地球降溫到 工業時代以前的溫度。 這份量少得驚人; 整個地球只要這一根水管。 當然,我們不會真的用水管, 可能會用飛機載上去之類的方式。 但,需要的量相當少, 就像是把一把白堊 丟到裝滿雨水的每個奧運游泳池中。 幾乎沒感覺。
So why don't people like this idea? Why isn't it taken more seriously? And there are some very good reasons for that. A lot of people really don't think we should be talking about this at all. And, in fact, I have some very good friends in the audience who I respect a lot, who really don't think I should be talking about this. And the reason is that they're concerned that if people imagine there's some easy way out, that we won't give up our addiction to fossil fuels. And I do worry about that. I think it's actually a serious problem. But there's also, I think, a deeper problem, which is: nobody likes the idea of messing with the entire earth -- I certainly don't. I love this planet, I really do. And I don't want to mess with it. But we're already changing our atmosphere, we're already messing with it. And so I think it makes sense for us to look for ways to mitigate that impact. And we need to do research to do that. We need to understand the science behind that.
所以,為什麼大家不喜歡這個想法? 它為何沒被更認真看待? 這背後有些很好的理由。 很多人完全不認為 我們應該要談這些。 事實上,在觀眾當中 有一些我非常要好的朋友, 我很尊敬他們, 他們完全不認為我應該來談這個。 因為他們關心的是, 如果大家知道會有簡單的解決方案, 那麼我們就不會放棄 對化石燃料的依賴了。 我確實也會擔心這點。 我認為這其實是個嚴重的問題。 但,我認為還有一個更深入的問題, 那就是:沒有人會喜歡 去亂搞整個地球── 我肯定不喜歡。 我愛這個星球,真的。 我不想亂搞它。 但我們已經在改變我們的大氣了, 我們已經在亂搞它了。 所以我認為這是合理的, 我們應該要找些方式 來把衝擊給減少。 我們需要去做相關的研究。 我們需要了解它背後的科學。
I've noticed that there's a theme that's kind of developed at TED, which is kind of, "fear versus hope," or "creativity versus caution." And of course, we need both of those. So there aren't any silver bullets. This is certainly not a silver bullet. But we need science to tell us what our options are; that informs both our creativity and our caution. So I am an optimist about our future selves, but I'm not an optimist because I think our problems are small. I'm an optimist because I think our capacity to deal with our problems is much greater than we imagine.
我注意到,在 TED 有個主題正在發展, 類似是「恐懼與希望」, 或「創意與謹慎」。 當然,我們兩者都需要。 沒有任何簡單快速的解法。 這肯定不是簡單快速的解決方法。 但我們需要科學 來告訴我們有哪些選項, 那樣就能同時為我們的 創意和謹慎提供資訊。 所以對於我們的未來, 我抱持著樂觀的態度, 但我樂觀的原因並不是 因為我們的問題很小。 我樂觀的原因是, 我認為我們處理問題的能力 遠超過我們的想像。
Thank you very much.
非常謝謝。
(Applause)
(掌聲)
This talk sparked a lot of controversy at TED2017, and we encourage you to look at discussions online to see other points of view.
這場演說在 TED 2017 引發了許多爭論, 我們鼓勵大家上網看看討論, 了解不同的觀點。