[A provocation from Danny Hillis:]
﻿【来自丹尼希利斯的挑衅：
[It's time to start talking about engineering our climate]
是时候谈谈如何治理气候问题了】
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.
是否可以创造一个恒温器， 能在任何时候 给地球降温？ 你也许会认为，如果有人已经 找到了可行的方法， 每个人都会非常激动， 而且关于这方面的研究也会有很多。 事实是，许多人明白如何做， 但是，这些方法并没有 得到相关研究的支持。 我认为，其中部分原因是 人们对这项研究存在着误解。 今天，我不会说服大家承认 我要说的是一个好办法， 但我会尝试让你们 对治理气候变化感兴趣， 并消除其中一些误解。
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.
太阳能地球工程的基本思想就是 我们通过把一部分阳光 反射回太空的方式， 给地表的物体降温。 数十年来人们都在讨论 如何实现这种想法， 低空的云，就是一种很棒的方式， 人们都知道，云底下凉快。 我喜欢这种云是因为，它的含水量 和周围的空气一致。 这就意味着，只要空气的 流动发生一点改变， 就能形成云。 我们经常在空中制造人造云， 这些云是飞机飞行痕迹， 是人造水云， 是由喷气式发动机产生的。 我们已经在不经意间改变 地球上的云了。 或者，你可能更愿意认为 这是政府的绝密阴谋。
(Laughter)
（笑声）
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.
我们在这方面已经做了很多工作。 这是一张由NASA 拍摄的船舶航线图。 船舶的航行会导致云的形成， 而且这种影响效应非常大， 大到能让大气温度降低一度， 从而减缓了全球变暖效应。 也就是说，我们已经 开始研究太阳能工程了。 有很多关于实现这一工程的想法， 人们着眼于方方面面， 从在太空建造巨大的遮阳伞， 到在海洋里产生气泡。 其中有一部分想法是十分可行的。 最近，哈佛的大卫 · 凯斯 提出了一个想法， 将白垩粉（如粉笔灰）洒到平流层中， 用来反射太阳光。 这确实是一个不错的注意， 因为白垩是地球上 最常见的矿物之一， 而且非常安全—— 安全到可以添加到婴儿的食物中。 如果你把白垩投入到平流层中， 它会花几年的时间才落到地面， 并溶解在雨水中。 在你担心雨水中的白垩之前， 我先向你们解释一下， 我们使用的白垩是有多么的少。 可以证明它的用量非常容易计算。 这是我粗略的计算。
(Laughter)
（笑声）
(Applause)
（掌声）
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.
我可以向各位保证， 已经有人进行过更详细的计算， 得出的结果是一致的—— 你需要每年以10太克（1Tg=10^9公斤）的 速率向平流层投放白垩， 来消除二氧化碳的影响， 这是我们已经在做的—— 仅仅是温度方面的影响， 不包含其他的影响。 那么这个数字是什么概念？ 我想象不出每年 10太克是什么样子的。 所以，我请了剑桥消防部门， 以及泰勒 · 米尔索 帮我一个忙。 这根水管的出水量 就是一年10太克。 这个规模 就是让地球降温到 工业时代前的水平， 需要将白垩注入到平流层的量。 这个量小得惊人，整个地球 只需要这一根水管就够了。 当然，你不必使用一根水管， 可以通过飞机，或其他 类似的方法将白垩带上去。 这个量非常的小， 就好像用手抓一把白垩 放入与奥运会标准泳池 等量的雨水中。 很难察觉出变化。
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.
那么为什么 人们不喜欢这种方法？ 为什么不重视这种方法？ 有一些很好的理由。 有很多人不认为 我们应当去研究这种方法。 事实上，在座的观众中 有一些是我非常要好的朋友， 我非常尊敬他们， 他们认为我不应该研究这个。 因为他们关心的是， 人们是否还能想出更简单的办法， 来摆脱对化石燃料的依赖。 我也关心这一点， 因为我认为这是 一个很严重的问题， 也是一个很深奥的问题。 没有人喜欢让整个地球 陷入混乱的想法， 我当然也不喜欢。 我喜欢这个星球，说真的， 我不想给地球制造任何麻烦。 但是我们已经在改变 我们的大气层了， 我们已经把它搞得乌烟瘴气了。 所以我们应该寻找一些方法， 减缓大气变化造成的影响。 这就意味着我们需要去研究它， 我们需要弄清楚 这背后的科学道理。
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中 有关于发展的主题， 类似于“恐惧与希望”， 或者是“创造与谨慎”。 当然，我们也需要这些思想。 但这不是完美的解决办法， 这确实不是完美的解决办法。 但我们需要通过科学知道， 我们有哪些选择； 这会为我们的创造力和 谨慎态度带来指导。 对人类的未来， 我是一个乐观主义者， 我乐观的原因 并不是因为这些问题很小， 而是因为我认为 我们有能力解决这些问题， 而且方法比我们想象的要好。
Thank you very much.
非常感谢。
(Applause)
（掌声）
This talk sparked a lot of controversy at TED2017, and we encourage you to look at discussions online to see other points of view.
这场演讲在 TED2017  引起了许多议论， 我们鼓励观众们 上网了解这些讨论， 了解其他的观点。