To avoid dangerous climate change, we're going to need to cut emissions rapidly.
为了避免危险的气候变化，我们需要迅速减少排放。
That should be a pretty uncontentious statement, certainly with this audience.
这一点毋庸置疑，在座各位都明白。
But here's something that's slightly more contentious: it's not going to be enough.
但还有一点同样毋庸置疑：就是仅仅降排放是不够的。
We will munch our way through our remaining carbon budget for one and a half degrees in a few short years,
我们要想尽办法在未来几年内，将我们剩余的碳预算控制在1到1.5度之内，
and the two degree budget in about two decades.
在大概未来20年里，将其控制在2度之内。
We need to not only cut emissions extremely rapidly, we also need to take carbon dioxide out of the atmosphere. Thank you.
我们不仅要极度迅速地降低碳排放，我们还要减少大气层中已经有的二氧化碳。谢谢。
I work assessing a whole range of these proposed techniques to see if they can work.
我的工作就是评估这一系列的技术，去看看它们究竟有没有用。
We could use plants to take CO2 out, and then store it in trees, in the soil, deep underground or in the oceans.
我们可以用植物吸收二氧化碳，然后保存在树木里、土壤中、地底下或者深海中。
We could build large machines, so-called artificial trees, that will scrub CO2 from the air.
我们可以建造大型机器，即所谓的人工树木，可以从空气中吸收二氧化碳。
For these ideas to be feasible,
这些想法要成为现实，
we need to understand whether they can be applied at a vast scale in a way that is safe, economic and socially acceptable.
我们需要了解，它们是否可以以安全、经济以及被社会所接受的方式被大规模应用。
All of these ideas come with tradeoffs. None of them are perfect, but many have potential.
所有这些想法都需要权衡。没有哪一个是完美的，但很多都非常有前景。
It's unlikely that any one of them will solve it on its own.
没有哪一个方案能独自解决问题。
There is no silver bullet, but potentially together,
没有捷径，但联合起来，
they may form the silver buckshot that we need to stop climate change in its tracks.
它们就可能发挥很大的作用，能一举解决气候变化问题。
I'm working independently on one particular idea
我独立研究其中一个方案，
which uses natural gas to generate electricity in a way that takes carbon dioxide out of the air. Huh? How does that work?
即用天然气来发电来从空气中吸收二氧化碳。啊？怎么做到的？
So the Origen Power Process feeds natural gas into a fuel cell.
奥利金发电过程：将天然气加入燃料机能中。
About half the chemical energy is converted into electricity,
其中一半的化学能转化为电能，剩下的转化为热，
and the remainder into heat, which is used to break down limestone into lime and carbon dioxide.
可以用来分解石灰岩，得到石灰和二氧化碳。
Now at this point, you're probably thinking that I'm nuts. It's actually generating carbon dioxide.
到这一步，你们可能会想这人是个傻子吧。这实际上是在产生二氧化碳。
But the key point is, all of the carbon dioxide generated,
关键在于，所有产生的二氧化碳，
both from the fuel cell and from the lime kiln, is pure, and that's really important,
无论是来自燃料机能还是石灰岩，都是纯净的，那是非常重要的，
because it means you can either use that carbon dioxide or you can store it away deep underground at low cost.
因为这意味着你要么可以使用二氧化碳，要么可以用很低的成本将它们存放到地底深处。
And then the lime that you produce can be used in industrial processes, and in being used, it scrubs CO2 out of the air.
生产出来的石灰可以用在工业过程中，在使用过程中，它可以吸收空气中的二氧化碳。
Overall, the process is carbon negative. It removes carbon dioxide from the air.
整体来看，这个过程是消耗二氧化碳的。它从空气中吸收二氧化碳。
If you normally generate electricity from natural gas, you emit about 400 grams of CO2 into the air for every kilowatt-hour.
如果你通常用天然气发电，大概每千瓦时有400克二氧化碳要排放到空气中。
With this process, that figure is minus 600.
通过上面这个过程，那个数字是负600克。
At the moment, power generation is responsible for about a quarter of all carbon dioxide emissions.
目前，发电过程占了所有二氧化碳排放的四分之一。
Hypothetically, if you replaced all power generation with this process,
理论上讲，如果能将发电过程用刚刚这种方式取代，
then you would not only eliminate all of the emissions from power generation
我们不仅可以将发电产生的二氧化碳全部消除，
but you would start removing emissions from other sectors as well, potentially cutting 60 percent of overall carbon emissions.
还可以减少在其它领域产生的排放，整体上可能降低60%的碳排放。
You could even use the lime to add it directly to seawater to counteract ocean acidification,
你甚至可以将石灰直接投入海水，来抵消海水酸化，
one of the other issues that is caused by CO2 in the atmosphere.
这是大气中二氧化碳增多导致的另一个问题。
In fact, you get more bang for your buck.
实际上这还有更大的好处。
You absorb about twice as much carbon dioxide when you add it to seawater as when you use it industrially.
当你把石灰投入海水，相比将其用于工业，这能吸收2倍的二氧化碳。
But this is where it gets really complicated.
但这也是事情开始变得复杂的地方。
While counteracting ocean acidification is a good thing, we don't fully understand what the environmental consequences are,
尽管抵消海洋酸化是一件好事，但我们还没完全搞清楚它对环境产生的影响，
and so we need to assess whether this treatment is actually better than the disease that it is seeking to cure.
所以我们要评估清楚解决方案和问题本身，两害相权取其轻。
We need to put in place step-by-step governance for experiments to assess this safely.
我们要边试边做，仔细评估其可行性。
And the scale: to avoid dangerous climate change, we are going to need to remove trillions
说到规模：如果要避免危险的气候变化，我们需要减少几万亿，
and yes, that's trillions with a T -- trillions of tons of carbon dioxide from the atmosphere in the decades ahead.
没错，是几万亿--在未来数十年内，几万亿吨二氧化碳。
It will cost a few percent of GDP -- think defense-sized expenditure,
这将花掉一部分GDP--想想国防开支，
lots of industrial activity and inevitably harmful side effects. But if the scale seems enormous,
众多的工业活动，以及不可避免的、有害的副作用。但如果这个规模看起来很大，
it is only because of the scale of the problem that we are seeking to solve. It's enormous as well.
仅仅是因为我们想要解决的问题本身的规模也很大。

We can no longer avoid these thorny issues.
我们不可以再逃避这种尖锐的问题。
We face risks whichever way we turn:
无论走哪条路都会面临风险：
a world changed by climate change or a world changed by climate change and our efforts to counter climate change.
要么是被气候变化改变的世界，要么是被气候变化改变的世界加上我们努力对抗气候的变化。
Would that it were not so, but we can no longer afford to close our eyes, block our ears, and say la-la-la.
无论怎样，我们都不能视而不见，充耳不闻，自己骗自己了。
We need to grow up and face the consequences of our actions.
我们要像成年人一样，面对自己行动带来的后果。
Does talk of curing climate change undermine the will to cut emissions? This is a real concern,
谈论终结气候变化会不会减弱我们减少排放的意愿？这是一个真正的担忧，
so we need to emphasize the paramount importance of reducing emissions and how speculative these ideas are.
因此我们要强调减排的极端重要性，以及这些方案的风险性。
But having done so, we still need to examine them.
但与此同时，我们仍需要检查这些方案。
Can we cure climate change? I don't know, but we certainly can't if we don't try.
我们能阻止气候变化吗？我不知道，但如果我们不尝试就肯定不行。
We need ambition without arrogance. We need the ambition to restore the atmosphere,
我们要有雄心壮志，要保持谦卑。我们要有志恢复大气层，
to draw down carbon dioxide back to a level that is compatible with a stable climate and healthy oceans.
减少二氧化碳到和一个稳定的气候和健康的海洋兼容的水平。
This will be an enormous undertaking. You could describe it as a cathedral project.
这将是一个艰巨的任务。你可以将它类比建造一座教堂。
Those involved at the outset may draft the plans and dig the foundations, but they will not raise the spire to its full height.
那些最开始参与的人，可能设计了图纸，挖好了地基，但他们不会一直做直到教堂的尖顶高耸入云。
That task, that privilege, belongs to our descendants.
这项任务，这项殊荣，属于我们的后代。
None of us will see that day, but we must start in the hope that future generations will be able to finish the job.
我们无缘见证那一天，但我们必须开始行动，满怀希望，我们的后代会完成这项工作。
So, do you want to change the world? I don't.
那么，你们想不想改变世界？我不想。
I do not seek the change the world, but rather keep it as it's meant to be. Thank you.
我不寻求改变世界，我更想将它保持在应有的样子。谢谢大家。
Thanks. I just want to ask you a couple of other questions.
谢谢。我想问你几个问题。
Tell us a bit more about this idea of putting lime in the ocean.
跟我们说说把石灰投入海洋这件事吧。
I mean, on the face of it, it's pretty compelling -- anti-ocean acidification -- and it absorbs more CO2.
乍一听，这主意很引人入胜--防止海洋酸化--吸收更多的二氧化碳。
You talked about, we need to do an experiment on this. What would a responsible experiment look like?
你刚刚提到，我们还需要进行实验。那么一个可靠的实验应该是什么样的呢？
So I think you need to do a series of experiments, but you need to do them just very small stage-by-stage.
我认为需要进行一系列的实验，但是你要一步一步来。
In the same way, when you're trialing a new drug, you wouldn't just go into human trials straight off.
跟测试一种新药一样，你不能一上来就进行人体实验。
You would do a small experiment.
你要先进行小范围实验。
And so the first things to do are experiments entirely on land, in special containers, away from the environment.
因此最初的实验是完全在陆地上进行，在特殊的容器中，远离真实环境。
And then once you are confident that that can be done safely, you move to the next stage.
直到你确定它可以安全进行，你才会进入下一阶段。
If you're not confident, you don't. But step by step.
如果不确定，就不会继续。要一步一步来。
And who would fund such experiments?
那么谁来资助这些实验？
Because they kind of impact the whole planet at some level. Is that why nothing is happening on this?
因为某种程度上这会影响到整个地球。是不是因为这个所以目前还没有进展？
So I think you can do small-scale experiments in national waters,
我认为可以在全国海域进行小规模实验，
and then it's probably the requirement of national funders to do that.
这可能需要国家的资助来完成。
But ultimately, if you wanted to counter ocean acidification in this way on a global scale,
但最终，如果你想要在全球范围内以这样的方式解决海洋酸化，
you would need to do it in international waters, and then you would need to have an international community working on it.
你需要在公海进行操作，需要国际社会的支持。
Even in national waters, you know, the ocean's all connected. That lime is going to get out there.
即便是在国家领海，海洋是互相联通的。石灰也会漂到各处。
And people feel outraged about doing experiments on the planet, as we've heard. How do you counter that?
据我的了解，人们对于这种实验非常愤怒。你怎么应对？
I think you touch on something which is really important. It's about a social license to operate.
我认为你提到了一个非常重要的问题。就是社会对于某项行动的完全认可。
And I think it may be that it is impossible to do,
我认为这似乎是一件不可能完成的任务，
but we need to have the courage to try, to move this forward, to see what we can do, and to engage openly.
但我们必须要勇于尝试，往前推进，看我们能做什么并公开参与。
And we need to engage with people in a transparent way. We need to ask them beforehand.
我们需要对人们开诚布公。我们要事先通知他们。
And I think if we ask them, we have to be open to the possibility that the answer will come back, "No, don't do it."
我认为如果我们问了他们，就要准备好面对可能的答案，“不，不要这么干。”
Thanks so much. That was really fascinating. Thank you.
非常感谢。非常棒的演讲。谢谢。