A new way to remove CO2 from the atmosphere | Jennifer Wilcox

翻译人员: Annie Zhang 校对人员: He Huang

Four hundred parts per million:

百万分之四百：

that's the approximate concentration of CO2 in the air today.

这就是现在空气里 二氧化碳大概的浓度。

这意味着什么呢？

What does this even mean?

意味着每四百个二氧化碳分子，

For every 400 molecules of carbon dioxide,

we have another million molecules of oxygen and nitrogen.

都混了另外一百万个氧和氮分子。

今天这个房间里大概有1800人。

In this room today, there are about 1,800 of us.

Imagine just one of us was wearing a green shirt,

想象一下我们当中 只有一个人穿着绿色衬衫，

and you're asked to find that single person.

而你被要求找到那个人。

这就是我们从空气中 直接捕获二氧化碳

That's the challenge we're facing when capturing CO2

directly out of the air.

需要面临的挑战。

Sounds pretty easy,

把二氧化碳从空气中提取出来，

pulling CO2 out of the air.

听起来很简单，

It's actually really difficult.

但这实际上是个很复杂的过程。

But I'll tell you what is easy:

但我要告诉你什么是简单的：

avoiding CO2 emissions to begin with.

在源头减少二氧化碳排放。

But we're not doing that.

但是我们并没有真正这样做。

所以我们现在得考虑如何逆转现状；

So now what we have to think about is going back;

pulling CO2 back out of the air.

将二氧化碳从空气中移除。

Even though it's difficult, it's actually possible to do this.

虽然这个过程很困难， 但是依然有可能实现。

And I'm going to share with you today where this technology is at

我今天将与你们分享 用来移除二氧化碳的科技，

and where it just may be heading in the near future.

以及在不久的将来，它会朝哪个方向发展。

Now, the earth naturally removes CO2 from the air

地球能够自然地通过海水， 泥土，草木甚至是石头

by seawater, soils, plants and even rocks.

将二氧化碳从空气中移除。

And although engineers and scientists are doing the invaluable work

尽管工程师和科学家们 为了加快这个自然的过程

to accelerate these natural processes,

做了许多宝贵的工作，

it simply won't be enough.

但还远远不够。

The good news is, we have more.

好消息是， 我们还有别的技术。

感谢人类的聪明才智，

Thanks to human ingenuity, we have the technology today

to remove CO2 out of the air

我们今天才能拥有通过化学制造

using a chemically manufactured approach.

将二氧化碳从空气中移除的科技。

I like to think of this as a synthetic forest.

我把它称为人工森林。

There are two basic approaches to growing or building such a forest.

总的来说，有两种方法 可以实现人工森林。

One is using CO2-grabbing chemicals dissolved in water.

一种是使用溶于水的 二氧化碳捕集材料。

Another is using solid materials with CO2-grabbing chemicals.

另一种是使用固态的 二氧化碳捕集材料。

No matter which approach you choose, they basically look the same.

无论你选择哪种方法， 它们看起来都差不多。

So what I'm showing you here is what a system might look like

我现在向你们展示的是 一个具备这种功能的系统

to do just this.

可能的样子。

它被称为空气接触器。

This is called an air contactor.

You can see it has to be really, really wide

可以看到，它必须设计得非常非常宽，

in order to have a high enough surface area

这样才能获得足够大的表面积

to process all of the air required,

来处理所有需要的空气，

because remember,

请谨记，

we're trying to capture just 400 molecules out of a million.

我们要尝试在一百万个分子之中 捕获仅仅四百个分子。

Using the liquid-based approach to do this,

若使用液体材料来捕获二氧化碳，

you take this high surface area packing material,

需要选用表面积大的填充材料，

you fill the contactor with the packing material,

将空气接触器装满，

you use pumps to distribute liquid across the packing material,

再使用泵驱动，并确保液体 在填充材料之间充分流动。

and you can use fans, as you can see in the front,

然后你就可以使用风扇，从装置的前面

将空气吹进装置， 以气泡的形态穿过液体。

to bubble the air through the liquid.

空气中的二氧化碳 与液体材料发生反应，

The CO2 in the air is separated [by] the liquid

by reacting with the really strong-binding CO2 molecules in solution.

从而将二氧化碳分子分离出来。

And in order to capture a lot of CO2,

为了能捕获更多的二氧化碳，

you have to make this contactor deeper.

还必须将接触器造得更深。

But there's an optimization,

但是这种提升并不是无限的，

because the deeper you make that contactor,

因为接触器造得越深，

the more energy you're spending on bubbling all that air through.

制造气泡所消耗的能量也越多。

所以直接捕捉空气的空气接触器 就具备了这个独一无二的设计，

So air contactors for direct air capture have this unique characteristic design,

where they have this huge surface area, but a relatively thin thickness.

巨大的表面积和相对较薄的厚度。

在二氧化碳被捕获之后，

And now once you've captured the CO2,

我们还需要能够循环使用 用来捕获它的材料，

you have to be able to recycle that material that you used to capture it,

over and over again.

持续不断进行捕获。

The scale of carbon capture is so enormous

毕竟，当碳捕获具备了庞大的规模，

that the capture process must be sustainable,

其捕获方法必须能够满足长远需求

and you can't use a material just once.

并能重复利用材料。

And so recycling the material requires an enormous amount of heat,

另外，重复利用材料的过程 需要消耗大量的热量，

试想一下： 二氧化碳在空气中是如此稀薄，

because think about it: CO2 is so dilute in the air,

that material is binding it really strong,

材料对它的约束力就会非常大，

你需要消耗很多热量 才能回收这个材料。

and so you need a lot of heat in order to recycle the material.

And to recycle the material with that heat,

所以你消耗热量回收材料时，

从空气中收集的浓缩二氧化碳

what happens is that concentrated CO2 that you got from dilute CO2 in the air

is now released,

将被释放出来，

and you produce high-purity CO2.

你将得到高纯度的二氧化碳。

And that's really important,

这一点很重要，

because high-purity CO2 is easier to liquify,

因为高纯度的二氧化碳更容易液化，

easier to transport, whether it's in a pipeline or a truck,

无论是利用管道还是卡车， 都比气态二氧化碳更容易运输，

or even easier to use directly,

甚至更容易被直接使用，

say, as a fuel or a chemical.

比如作为燃料或者化学品。

So I want to talk a little bit more about that energy.

关于能量，我想再多讲一些。

The heat required to regenerate or recycle these materials

再生或者回收那些材料的热量需求

决定了这个过程需要的能量和附随的成本。

absolutely dictates the energy and the subsequent cost of doing this.

So I ask a question:

我想问一个问题：

How much energy do you think it takes

你觉得在一年内

to remove a million tons of CO2 from the air

从空气中移除一百万吨的二氧化碳

in a given year?

需要多少能量？

答案是： 一个发电厂。

The answer is: a power plant.

It takes a power plant to capture CO2 directly from the air.

需要一个发电厂来提供从空气中 捕获二氧化碳所需要的能量。

Depending on which approach you choose,

发电厂的发电量，

the power plant could be on the order of 300 to 500 megawatts.

取决于选择的方法， 可能在300到500兆瓦之间。

And you have to be careful about what kind of power plant you choose.

还要谨慎选择发电厂的燃料类别。

If you choose coal,

如果选择的是煤，

you end up emitting more CO2 than you capture.

产生的二氧化碳会比捕获的还多。

Now let's talk about costs.

现在让我们谈谈成本问题。

An energy-intensive version of this technology

如果仅仅为了捕获一吨二氧化碳

could cost you as much as $1,000 a ton

而选择在该技术上投入大量能源，

just to capture it.

其花费将多达一千美金。

让我们解释一下这句话。

Let's translate that.

If you were to take that very expensive CO2 and convert it to a liquid fuel,

如果你要把非常昂贵的 二氧化碳转化成液体燃料，

that comes out to 50 dollars a gallon.

燃料价格将会高达 五十美元一加仑。

这太贵了；完全是不可行的。

That's way too expensive; it's not feasible.

So how could we bring these costs down?

那么我们要怎样降低费用？

That's, in part, the work that I do.

这就是我所做的部分工作。

There's a company today, a commercial-scale company,

当前有一个公司， 一个商业规模的公司，

that can do this as low as 600 dollars a ton.

可以使费用降到每吨六百元。

There are several other companies that are developing technologies

还有其他几个开发技术的公司，

还可以进一步降低成本。

that can do this even cheaper than that.

I'm going to talk to you a little bit

我要向你们简单介绍一下

about a few of these different companies.

这些不同的公司。

One is called Carbon Engineering.

其中一个叫做Carbon Engineering，

位于加拿大。

They're based out of Canada.

They use a liquid-based approach for separation

他们使用基于液体的分离方法

combined with burning super-abundant, cheap natural gas

结合过剩的， 廉价的天然气

to supply the heat required.

来提供所需要的热量。

他们发明了一个很巧妙的方法，

They have a clever approach

that allows them to co-capture the CO2 from the air

可以从空气中捕获二氧化碳的同时，

也捕获燃烧天然气产生的二氧化碳。

and the CO2 that they generate from burning the natural gas.

And so by doing this,

这样一来，

they offset excess pollution and they reduce costs.

他们就抵消了过度污染的 影响，也降低了成本。

位于瑞士的Climeworks 和位于美国的Global Thermostat

Switzerland-based Climeworks and US-based Global Thermostat

use a different approach.

使用的则是不同的方法，

They use solid materials for capture.

固体材料捕获。

Climeworks uses heat from the earth,

Climateworks 使用来自地球的热量

or geothermal,

或者地热能，

or even excess steam from other industrial processes

甚至是来自其他工业过程的过量蒸汽

to cut down on pollution and costs.

来减少污染和降低费用。

Global Thermostat takes a different approach.

Global Thermostat则另辟蹊径，

They focus on the heat required

他们专注于所需的热量

and the speed in which it moves through the material

以及它穿过材料的速度，

so that they're able to release and produce that CO2

于是就可以在一个很快的速率下

释放和生产二氧化碳，

at a really fast rate,

这使得他们采用了更密致的设计，

which allows them to have a more compact design

and overall cheaper costs.

以及整体上更低廉的费用。

And there's more still.

还有很多这样的例子。

A synthetic forest has a significant advantage over a real forest: size.

人造森林与天然森林相比 有一个显著的优势： 规模。

This next image that I'm showing you is a map of the Amazon rainforest.

这是亚马逊热带雨林的地图。

The Amazon is capable of capturing 1.6 billion tons of CO2 each year.

亚马逊地区每年能捕获 16亿吨的二氧化碳。

This is the equivalent of roughly 25 percent

大约等于美国每年排放量的

of our annual emissions in the US.

百分之二十五。

而要捕获等量的二氧化碳所需的

The land area required for a synthetic forest

or a manufactured direct air capture plant

人工森林或者人造空气捕获工厂，

to capture the same

其占地面积

is 500 times smaller.

只有天然森林的五百分之一。

In addition, for a synthetic forest,

另外，人工森林

you don't have to build it on arable land,

不需要在耕地上建造，

所以并不会占用畜牧和农耕土地，

so there's no competition with farmland or food,

and there's also no reason to have to cut down any real trees

而且我们也不需要 砍去任何自然生长的树木

to do this.

来建造人工森林。

I want to step back,

我想退一步，

and I want to bring up the concept of negative emissions again.

再次提出负排放的概念。

Negative emissions require that the CO2 separated

负排放，需要被分离的二氧化碳

be permanently removed from the atmosphere forever,

永久性地从大气层中去除，

which means putting it back underground,

这意味着把它送回地下，

也就是它最初所在的地方。

where it came from in the first place.

But let's face it, nobody gets paid to do that today --

但请让我们面对现实吧， 至今都没有人以此为生——

至少相关从业者数量还远远不够。

at least not enough.

所以开发这些技术的公司

So the companies that are developing these technologies

are actually interested in taking the CO2

其实是对获取二氧化碳感兴趣，

为了从中造出有价值的东西， 一个可销售的产品。

and making something useful out of it, a marketable product.

It could be liquid fuels, plastics

它可以是液体燃料， 塑料，

or even synthetic gravel.

甚至是合成的砾石。

And don't get me wrong -- these carbon markets are great.

别误会我的意思—— 这些碳源的市场非常好。

但是我也不想让你们 产生错误的幻想。

But I also don't want you to be disillusioned.

These are not large enough to solve our climate crisis,

这些市场还不够大， 不足以解决气候危机，

所以我们需要认真思考一下

and so what we need to do is we need to actually think about

what it could take.

还能做些什么来解决危机。

One thing I'll absolutely say is positive about the carbon markets

关于碳市场的一个绝佳的事实就是，

is that they allow for new capture plants to be built,

它至少支撑了建造新的捕获工厂，

每建造一个捕获工厂，

and with every capture plant built,

we learn more.

我们都会学到更多；

And when we learn more,

当我们学到更多，

we have an opportunity to bring costs down.

我们就能不断地降低成本。

But we also need to be willing to invest

但作为一个国际社会，

as a global society.

我们还需要愿意去投资。

We could have all of the clever thinking and technology in the world,

我们有世界上所有的奇妙思想和科技，

but it's not going to be enough

但是这还远无法

in order for this technology to have a significant impact on climate.

让这项技术对气候带来显著的改善。

We really need regulation,

我们还切实地需要法规扶持，

we need subsidies,

我们需要补贴，

taxes on carbon.

碳税，

我们当中有一部分人 绝对愿意为此花更多的钱，

There are a few of us that would absolutely be willing to pay more,

但为了走向零碳排放，

but what will be required

is for carbon-neutral, carbon-negative paths

甚至是碳负排放的道路，

to be affordable for the majority of society

我们需要让社会中的大多数人 都能够承担得起这部分费用，

才能真正影响气候。

in order to impact climate.

In addition to those kinds of investments,

除了这些投资，

我们还需要人们在研发项目中投资。

we also need investments in research and development.

So what might that look like?

这意味着什么呢？

In 1966, the US invested about a half a percent of gross domestic product

1966年， 美国百分之五十的GDP

in the Apollo program.

被用于投资阿波罗计划。

It got people safely to the moon

该计划帮助人类安全地登上了月球，

and back to the earth.

并顺利返回地球。

Half a percent of GDP today is about 100 billion dollars.

而在今天，一半的GDP 大概是一千亿美金。

So knowing that direct air capture

所以当知道直接捕获空气

is one front in our fight against climate change,

和与气候变化做斗争 是同一个战线后，

imagine that we could invest 20 percent, 20 billion dollars.

想象一下我们能够投资 20%的GDP， 两百亿美元。

Further, let's imagine that we could get the costs down

更进一步，让我们设想一下降低成本

to a 100 dollars a ton.

到100美金一吨。

That's going to be hard, but it's part of what makes my job fun.

这很困难， 但也正是我工作中的乐趣所在。

And so what does that look like,

两百亿美金，一百美金一吨，

20 billion dollars,100 dollars a ton?

是个什么概念呢？

That requires us to build 200 synthetic forests,

这需要我们建造二百个人工森林，

each capable of capturing a million tons of CO2 per year.

每个人工森林一年能 捕获一百万吨的二氧化碳。

That adds up to about five percent of US annual emissions.

这加起来相当于美国每年 碳排放量的百分之五。

听起来好像不多。

It doesn't sound like much.

Turns out, it's actually significant.

实际上，效果已经相当明显了。

If you look at the emissions associated with long-haul trucking

如果你查看长途运输

and commercial aircraft,

和商用飞机产生的碳排放，

they add up to about five percent.

其合计总量就达到了百分之五左右。

Our dependence on liquid fuels makes these emissions

我们对液体燃料的依赖 使这样的碳排放量

非常难以避免。

really difficult to avoid.

So this investment could absolutely be significant.

所以毋庸置疑，这项研究意义重大。

Now, what would it take in terms of land area to do this,

那么要建造200个工厂，

200 plants?

需要多少土地呢？

It turns out that they would take up about half the land area of Vancouver.

事实上，它们将占据 温哥华大约一半的土地面积。

That's if they were fueled by natural gas.

这还是在利用天然气 作为燃料的前提下。

But remember the downside of natural gas -- it also emits CO2.

但是别忘了天然气的缺点—— 燃烧时也会排放二氧化碳。

So if you use natural gas to do direct air capture,

所以如果你使用天然气直接捕获空气，

you only end up capturing about a third of what's intended,

你最终只会捕获到预期量的三分之一，

unless you have that clever approach of co-capture

除非你有像Carbon Engineering一样

that Carbon Engineering does.

同时捕获两者的方法。

And so if we had an alternative approach

如果我们有一个替代的方法，

and used wind or solar to do this,

使用风力发电或者太阳能发电，

the land area would be about 15 times larger,

但随之所需的土地面积 可能会扩大十五倍，

looking at the state of New Jersey now.

和现在的新泽西州一样大。

One of the things that I think about in my work and my research

我在工作和研究时经常思考的一件事，

is optimizing and figuring out where we should put these plants

就是优化和解决两个问题， 将这些工厂放在哪里，

and think about the local resources available --

以及如何就地取材——

whether it's land, water, cheap and clean electricity --

是否有足够的土地面积， 水资源， 廉价和无污染的电能——

因为， 例如无污染的电能

because, for instance, you can use clean electricity

to split water to produce hydrogen,

可以把水分解成氢气，

which is an excellent, carbon-free replacement for natural gas,

这是一个极好的， 无碳的天然气替代品，

to supply the heat required.

可以提供所需的热量。

But I want us to reflect a little bit again on negative emissions.

但是我想提醒大家再次 对负排放进行反思。

Negative emissions should not be considered a silver bullet,

负排放不应该被当作是万全之策，

but they may help us if we continue to stall

但是它们可以在实现 真正减少全球二氧化碳排放前

at cutting down on CO2 pollution worldwide.

帮我们争取一些时间。

But that's also why we have to be careful.

这也是为什么我们 必须小心谨慎。

This approach is so alluring that it can even be risky,

这个方法是如此的诱人， 甚至会产生负面效应，

as some may cling onto it as some kind of total solution to our climate crisis.

有些人过分依赖它，把它看作 能彻底解决气候危机的方案。

It may tempt people to continue to burn fossil fuels 24 hours a day,

它可以诱使人们 每年365天，每天24小时，

365 days a year.

继续燃烧化石燃料。

I argue that we should not see negative emissions

我认为我们不应该把负排放

as a replacement for stopping pollution,

当成中断污染的替代品，

but rather, as an addition to an existing portfolio that includes everything,

相反的， 应该把它当成现有的 改善环境措施的一个附加品，

from increased energy efficiency

从提高能源效率

to low-energy carbon

到低碳排放，

再到优化农业——

to improved farming --

will all collectively get us on a path to net-zero emissions one day.

总有一天，会让我们走上 一条零碳排放的道路。

A little bit of self-reflection:

我还想谈谈自己的一点反思：

my husband is an emergency physician.

我的丈夫是一位急诊医师。

And I find myself amazed by the lifesaving work

他和同事每天从事的

that he and his colleagues do each and every day.

救死扶伤的工作令我大为惊叹。

Yet when I talk to them about my work on carbon capture,

然而当我和他们谈起 我与碳捕获相关的工作，

I find that they're equally amazed,

他们也同样表示了赞叹，

and that's because combatting climate change by capturing carbon

因为通过捕获碳来对抗气候变化

isn't just about saving a polar bear

并不只是关于拯救北极熊

or a glacier.

或者防止冰川融化，

It's about saving human lives.

这是为了拯救人类。

A synthetic forest may not ever be as pretty as a real one,

人工森林可能没有天然森林的美观，

but it could just enable us to preserve not only the Amazon,

但是它不仅仅让我们保护有能力亚马逊，

but all of the people

还能保护所有

我们所爱的和珍惜的人，

that we love and cherish,

as well as all of our future generations

以及所有的子孙后代

和现代文明。

and modern civilization.

Thank you.

谢谢。

(Applause)

（掌声）