Can we solve global warming? Lessons from how we protected the ozone layer | Sean Davis

翻译人员: Yichen Huang 校对人员: jacks peng

So, I'm a climate scientist,

我是一位气候科学家，

and if this room is representative of the country we live in,

如果这个房间代表我们所处的国家，

that means about 60 percent of you, so maybe from about there over,

那么大约你们中的60%， 差不多从那里一直到我的右边，

don't strongly trust me for information on the causes of climate change.

不相信我在气候变化上的观点。

Now, I promise to tell the truth tonight,

我保证今晚说的都是真话，

but just to humor that demographic,

但是为了那些不相信我的人，

I've started this talk with a falsehood.

我会从一句假话谈起。

[The Paris Climate Accord is a product of the recognition

[巴黎气候协定是对 气候变化的全球共识的产物]

[巴黎气候协定是对 气候变化的全球共识的产物]

这话不是奥巴马总统说的。

that climate change is a global problem ...]

This statement was not made by President Obama.

是里根总统说的。

It was made by President Reagan,

而且，它不是关于气候变化 和巴黎气候协定的，

and it wasn't about climate change and the Paris Climate Accord.

It was actually about the Montreal Protocol

它其实是关于蒙提利尔协定

and stratospheric ozone depletion.

和平流层臭氧损耗的。

Now, I'm sure that many of you aren't familiar with this environmental problem,

我很确定你们当中很多人 不太熟悉臭氧层问题，

but you should be,

但你们应该熟悉，

because it's a rare environmental success story.

因为这是一个很罕见的 成功的环保案例。

And it's worth revisiting,

这值得我们从中学习，

because sometimes, we need to examine the world we've avoided

因为有时，我们需要从 所避免的环境灾难中学习，

in order to find guidance for the choices we make today.

才能更好地做出当下的选择。

So let's go back to the 1970s,

让我们回到1970年代。

when some questionable choices were made:

在那个时代，人们 做出了一些不当的选择：

first of all -- hoo -- hairstyles. (Laughs)

首先是发胶。 （笑声）

Second of all, objectively terrible quantities of hairspray,

其次，客观地说， 质量糟糕的喷发定型剂。

and third, CFCs, chlorofluorocarbons,

第三，CFC，也就是氯氟烃。

man-made chemicals that were used as propellant in aerosol spray cans.

CFC是人造的化学品， 被用作喷雾剂中的压缩气体。

And see, it turns out these CFCs were a problem

后来，人们发现CFC引发了一个问题，

because they were destroying the ozone layer.

因为它会破坏臭氧层。

Now I'm sure most of you have heard of the ozone layer,

我很确定大多数人都听说过臭氧层，

but why does it matter?

为什么我们要在意臭氧层呢？

Well, quite simply, the ozone layer is earth's sunscreen,

简单来说，臭氧层是地球的防晒霜，

and it's really fragile.

而且它十分脆弱。

If you could take all of the ozone,

臭氧大多都处于 地面以上20至25公里处，

which is mostly about 10 to 20 miles up above our heads,

若你取得地球上所有臭氧，

and compress it down to the surface of the earth,

然后把它们压缩在地球表面，

it would form a thin shell only about two pennies thick,

它会形成大概有两个分币厚的薄层，

about an eighth of an inch.

大概3毫米厚。

And that thin shell does an amazing amount of work, though.

而这薄薄一层臭氧其实十分重要。

It filters out more than 90 percent of the harmful UV radiation

它能抵御超过90%源自太阳的

有害紫外线辐射。

coming from the sun.

And while I'm sure many of you enjoy that suntan that you get

虽然我知道很多人都喜欢晒太阳，

from the remaining 10 percent, it causes a lot of problems:

但即使是剩下10%的 紫外线辐射也能造成很多麻烦：

cataracts,

如白内障，

damage to crops,

损害农作物，

damage to immune systems

损伤免疫系统，

and also skin cancer.

以及皮肤癌。

It's not an exaggeration

对臭氧层的威胁

to say that a threat to the ozone layer is a threat to human safety.

就是对人类安全的威胁， 并不是夸大其词。

And actually, ironically, it was human safety

讽刺的是，正是处于对人类安全的担忧，

that motivated the invention of CFCs in the first place.

促成了氟利昂的发明。

You see, in the early days of refrigeration,

在电冰箱刚刚投入使用时，

refrigerators used toxic and flammable chemicals

会使用有毒，易燃的化学品，

like propane and ammonia.

如丙烷和氨。

For good reason, the refrigeration industry

所以制冷工业想要一个

wanted a safe alternative,

更安全的替代物，

and they found that in 1928,

他们在1928年找到了它。

when a scientist named Thomas Midgley

一位叫做Thomas Midgley的科学家

synthesized the first commercially viable CFCs.

率先合成了商业上可用的CFC。

And in fact, Midgley famously inhaled CFCs and blew out a candle

事实上，Midgley在一场学术论坛上

亲自吸入了CFC并用其吹灭了一支蜡烛，

to demonstrate, at a scientific conference,

that they were safe and nonflammable.

来证明CFC十分安全并不易燃。

And in fact, as a scientist, I can tell you there is no way

其实，作为一名科学家，我可以告诉你，

you could get away with that kind of antic today.

现在你可没办法像他这样演示。

I mean, wow.

真的，这让人感觉不可思议。

But really, at the time,

而在那时，

CFCs were a really remarkable invention.

CFC是一项十分卓越的发明。

They allowed what we now know as modern-day refrigeration

它促成了当代的制冷技术，

and air-conditioning and other things.

还有空调等等。

So it wasn't actually until over 40 years later, in the 1970s,

直到四十年之后的1970年代，

when scientists realized that CFCs would break down high in the atmosphere

科学家们才意识到CFC 会在大气层的高处降解，

and damage the ozone layer.

破坏臭氧层。

And this finding really set off a lot of public concern.

这个发现引发了公众的担忧。

It led, ultimately, to the banning of CFC usage in aerosol spray cans

最后在1978年， 美国和一些其他国家禁止

in the US and a few other countries in 1978.

在喷雾剂中使用CFC。

Now, the story doesn't end there,

而故事可没在那时结束，

because CFCs were used in much more than just spray cans.

因为CFC不止被用在喷雾剂中。

In 1985, scientists discovered the Antarctic ozone hole,

在1985年，科学家发现了 南极上空的臭氧层空洞，

and this was a truly alarming discovery.

这是一项十分让人警醒的发现。

Scientists did not expect this at all.

科学家们完全没有预料到。

Before the Antarctic ozone hole,

在此前，

scientists expected maybe a five or 10 percent reduction

科学家们预期一个世纪中 大概会有5%至10%的

in ozone over a century.

臭氧衰减。

But what they found over the course of less than a decade

但他们发现，在不到十年中，

was that more than a third of the ozone had simply vanished,

在面积超过美国的地区上方，

over an area larger than the size of the US.

超过三分之一的臭氧消失了。

And although we now know that CFCs are the root cause of this ozone hole,

虽然我们现在知道CFC 是臭氧层空洞的祸根，

at the time, the science was far from settled.

当时，学术上还远远没有定论。

Yet despite this uncertainty,

而尽管有这样的不确定性，

the crisis helped spur nations to act.

那场危机却得以 促使各个国家采取行动。

So that quote that I started this talk with,

回到我开始时引用里根总统

about the Montreal Protocol, from President Reagan --

关于蒙特利尔协定的那句话——

that was his signing statement when he signed the Montreal Protocol

那是美国参议院一致通过之后，

after its unanimous ratification by the US Senate.

里根总统签订协议时候的声明。

这是一件真正值得庆祝的事。

And this is something that's truly worth celebrating.

In fact, yesterday was the 30th anniversary of the Montreal Protocol.

其实，昨天就是蒙特利尔协定 签订的三十周年。

(Applause)

（掌声)

Because of the protocol,

因为这项协定，

ozone-depleting substances are now declining in our atmosphere,

大气层中侵害臭氧的物质正在减少，

and we're starting to see the first signs of healing in the ozone layer.

而我们也已经看到了 臭氧层恢复的初步征兆。

And furthermore, because many of those ozone-depleting substances

而且，因为很多侵害臭氧的物质

are also very potent greenhouse gases,

同时也是强力的温室气体，

the Montreal Protocol has actually delayed global warming

蒙特利尔协定将全球变暖的发生

by more than a decade.

推迟了十年。

That's just wonderful.

那太棒了。

But I think it's worth asking the question,

但我觉得我们应该思索这个问题，

as we face our current environmental crisis, global warming,

特别是当我们面对当下 全球变暖的环境问题时，

what lessons can we learn from Montreal?

我们可以从蒙特利尔协定中学到什么？

Are there any? I think there are.

有值得借鉴之处吗？我觉得有。

First, we don't need absolute certainty to act.

首先，我们并不需要 百分之百确定才采取行动。

When Montreal was signed,

当蒙特利尔协定签订时，

we were less certain then of the risks from CFCs

我们对于CFC的危害远不如

than we are now of the risks from greenhouse gas emissions.

我们现在对温室气体的危害来的确定。

A common tactic that people who oppose climate action use

有些反对针对气候变化 采取行动的人常用的说辞

is to completely ignore risk and focus only on uncertainty.

就是无视风险而单单强调不确定性。

But so what about uncertainty?

不确定又如何呢？

We make decisions in the face of uncertainty all the time,

我们每时每刻都在面对不确定性。

literally all the time.

真的，每时每刻。

You know, I'll bet those of you who drove here tonight,

我想你们很多人都是开车来这里的，

you probably wore your seat belt.

你们大概系了安全带。

And so ask yourself,

请想一下，

你系安全带是因为有人告诉你，

did you wear your seat belt because someone told you

with a hundred percent [certainty]

你有百分之百的可能

that you would get in a car crash on the way here?

会在来这儿的路上出车祸吗？

Probably not.

大概不是。

So that's the first lesson.

所以这就是我们学到的第一件事。

Risk management and decision making always have uncertainty.

风险管理和决策制定永远都 伴随着不确定性。

Ignoring risk and focusing only on uncertainty is a distraction.

忽视风险而专注于不确定性 只会分散我们的注意力。

In other words, inaction is an action.

换句话说，不做选择也是一种选择。

Second, it takes a village to raise a healthy environment.

第二，创造健康的环境 需要来自多方的努力。

The Montreal Protocol wasn't just put together by industry and governments

蒙特利尔协定不仅仅 是由行业机构和政府

or environmental advocacy groups and scientists.

或是环保活动家和科学家单独制定的，

It was put together by all of them.

而是由他们所有人一起制定的。

They all had a seat at the table,

他们都有所参与，

and they all played an important role in the solution.

都在解决臭氧层问题中发挥了重要作用。

我想在这个方面，

And I think in this regard,

we're actually seeing some encouraging signs today.

我们在今天也做得很好。

We see not just environmental groups concerned about climate change

我们不仅看到环保组织 致力于对抗气候变化，

but also civic and religious groups,

还有公民运动和宗教组织，

军事组织和商业组织。

the military and businesses.

So wherever you find yourself on that spectrum,

所以不管你是谁，

we need you at the table,

我们需要你的参与，

because if we're going to solve global warming,

因为解决全球变暖

it's going to take actions at all levels,

需要各个层面的行动，

from the individual to the international

从个人到国际，

and everything in between.

还有两者之间的每个层面。

Third lesson:

第三点：

don't let the perfect be the enemy of the good.

不要拘泥于完美而止步不前。

While Montreal has become the brake pedal for stopping ozone depletion,

虽然蒙特利尔协定最终 成为了臭氧损耗的休止符，

at its beginning, it was more just like a tap on the brakes.

在最开始，它的效果并不明显。

It was actually the later amendments to the protocol

其实是之后对协定的修正

that really marked the decision to hit the brakes on ozone depletion.

真正阻止了臭氧损耗。

So to those who despair

所以对那些悲观主义者，

that the Paris Climate Accord didn't go far enough

他们觉得巴黎气候协定做的远远不够，

or that your limited actions on their own won't solve global warming,

或是一个人的努力解决不了全球变暖，

I say don't let the perfect be the enemy of the good.

我会说，不要拘泥于完美而止步不前。

And finally, I think it helps us to contemplate the world we've avoided.

最后，我想这有助于 我反思所避免的危害。

Indeed, the world we have avoided by enacting the Montreal Protocol

的确，我们通过蒙特利尔协定避免的

is one of catastrophic changes

是对环境和人类的

to our environment and to human well-being.

灾难性的变化。

By the 2030s, we'll be avoiding millions of new skin cancer cases per year

到2030年，我们会避免每年 数以百万计的皮肤癌病例

with a number that would only grow.

这个数字只会增长。

If I'm lucky, I'll live long enough to see the end of this animation

如果我够幸运，就能够 见证这场变化的结尾，

and to see the ozone hole restored to its natural state.

看到臭氧层恢复到它原初的状态。

So as we write the story for earth's climate future

所以，当我们在这个世纪以及未来

for this century and beyond,

书写地球气候的历史时。

we need to ask ourselves, what will our actions be

我们要问自己，我们要做什么

so that someone can stand on this stage

才能让30，50，或者100年后，

in 30 or 50 or a hundred years

有人能够站在这个舞台上，

to celebrate the world that they've avoided.

庆祝他们避免的种种灾害。

Thank you.

谢谢。

(Applause)

（掌声）