What lights up the screen that you're looking at right now?
是什么点亮了你正在看的屏幕？
Trace back the battery chargers and power cords and you'll end up at an electrical outlet,
从电池充电器和电源回溯，你会找到电源插座，
providing easy, safe access to reliable electricity.
它是提供可靠电力的简便、安全途径。
But beyond that outlet, the picture gets messier.
但在电源插座后面，画面就混乱许多。
It takes a lot of fuel to heat our homes, preserve our food, and our power our gadgets around the clock.
大量的燃料被用来保持我们的房间的温暖、保持食物的新鲜以及不间断地为我们的电子产品充电。
And for 40% of the world, that fuel is cheap, plentiful, and it's called coal.
世界上40%的燃料是廉价、丰富的，被称为煤炭的东西。
But coal also releases pollutants into the air,
但煤炭也会向空气中排放污染物，
like sulfur dioxide, nitrogen oxides, soot, and toxic metals, like mercury.
比如二氧化硫、一氧化氮、煤灰以及例如汞的有毒金属。
These cause environmental damage, like acid rain, and serious health problems.
这些造成环境破坏，如酸雨，也造成了严重的健康问题。
In fact, in 1952, coal burning caused such heavy smog in London
事实上，在1952年，煤炭的燃烧在伦敦造成了严重的雾霾，
that pedestrians couldn't even see their feet, and thousands of people died from ill health.
行人甚至看不到他们的脚，成千上万的人死于健康问题。
Since then, many countries have deployed technology to remove most of these pollutants before they reach the air.
从那以后，许多的国家已采用科学技术使得污染物在进入空气前就被去除掉了。
But now we have a new air pollution problem on our hands,
但现在我们手头上有新的污染问题，
one that doesn't show up in a cloud of dark smog, but in rising seas, floods, and heat waves.
一个是它不会展现黑色雾霾云，而是海平面上升、洪水及热浪。
It's global climate change, and again, the main culprit is coal.
这是全球气候变化，而其主要元凶又是煤炭。
It's responsible for 44% of global carbon dioxide emissions,
它造成了全球44%的二氧化碳排放，
which trap the sun's heat in the Earth's atmosphere, instead of letting it escape.
把太阳的热量捕获到地球大气中，而不是让它排放出去。
So now the question is how do we remove that bad stuff as well?
所以现在的问题是，我们该如何除掉这个坏东西？
That's the idea behind cleaner coal.
这是比较清洁的煤炭背后的理念。
Creating cleaner coal is really about trying to contain its ill effects
制造更清洁的煤炭在于抑制它的副作用，
with the help of special technologies that make the end product more acceptable.
使用特殊的技术使得最终的产物更加容易被接受。
Just like the most intriguing superheroes often have their own dark powers to overcome,
正如大多数神秘的超级英雄往往需要克服它们自身的黑暗能量，
so we can try and keep coal's negative forces in check.
我们也应该尝试把煤炭的负面作用控制在一定范围内。
But why don't we just exterminate coal if it takes that much effort to clean it up?
既然清洁煤炭需要花这么多功夫，为什么我们不摒弃它呢？
Simply, coal is extremely valuable to us, and it's easy to come by.
简单地说，碳对我们有非常重要的价值，而且它非常容易获得。
Compressed underground for ages,
通过在地下长时间的压缩，
coal holds chemical energy from plants that were fed from by the sun hundreds of millions of years ago, long before humans evolved.
煤炭包含了亿万年间从太阳到这个星球上来的化学能量，比人类演化史还长。
That makes coal energy dense, meaning it can be burned 'round the clock.
这使得煤炭的能量很密集，意味着它能燃烧很久。
It's also cheap, if you ignore the pollution costs, and should last us through the end of the 21st century.
它也很便宜，如果不计算污染成本的话，而且应该能一直用到21世纪末。
We've already got all the infrastructure in place for harnessing its power,
我们已经建立了治理它的设施，
and globally, although countries are making a move towards energy from cleaner and more renewable sources,
从全球来看，尽管各个国家在尝试获得清洁能源和可再生能源的方法，
there's no sign yet that coal use is slowing down.
目前仍没有现象显示煤炭的消耗正在减少。

In fact, as of 2012, over 1000 new coal plants have been proposed, mostly in China and India.
事实上，在2012年，至少1000个新的煤炭工厂正在被计划兴建，大部分在中国和印度。
Since for the time being coal is here to stay,
由于暂时煤炭还不会被取代，
experts say that if we want to reduce its emissions' impact on the atmosphere, and slow down climate change,
专家称如果我们希望减少碳排放对大气的影响，延缓气候变化，
we'll have to think of creative ways of reducing coal's destructive power.
我们需要想出一个减少煤炭破坏力的创新方法。
To do that, we need to strip it of its foul forces,
首先，我们需要限制它副作用，
all that toxic carbon dioxide that causes havoc in the atmosphere.
那就是对大气造成严重污染的有毒二氧化碳。
Then, we need to store the CO2 somewhere else.
其次，我们需要把二氧化碳储存到其他地方。
This mission is called carbon capture and sequestration, or CCS.
这个任务被称为“碳捕获和封存”，即CCS。
And as if carbon dioxide were some evil genie we didn't want to escape,
二氧化碳是我们不想放跑的邪恶精灵，
once it has been separated from coal, we've devised ways to banish it underground.
一旦它从煤炭中分离出来，我们设计了一些方法把它埋藏到地下。
We can do this by injecting it deep into the Earth, or by placing it deep under the ocean's surface.
我们可以把它注射到地底深处，或放置到深海底下。
Stripping away coal's negative elements can happen in three ways.
消除煤炭的不良影响可以通过三种途径。
First, and most commonly, as coal burns, the exhaust gas can be mixed with a compound called monoethanolamine.
首先，也是最普遍的，煤炭燃烧时排出的气体可以与被称为乙醇胺的复合物混合。
Like a forceful power-stripping magnet, this compound bonds to the CO2,
像一个强力的磁铁，将二氧化碳吸附起来，
yanking it out of the gas stream so it can be stored separately underground.
从而将CO2从大气中剥离出来，让我们可以将它单独地储存到地下。
Another method is to relieve coal of its CO2 before it even has a chance to be released as exhaust.
另一个方法是减少煤炭中的二氧化碳，在它还没有能被释放之前。
In this process, steam and oxygen swoop in to the rescue to convert coal into a special product called syngas,
在这个过程中，氧气和蒸汽被引入作为还原剂，将煤炭转化为一种特殊的产物，称为“合成气”，
made up of carbon monoxide and hydrogen and some CO2.
它由一氧化碳，氢气和二氧化碳组成。
Zap that with some water vapor, and the carbon monoxide gets converted into carbon dioxide, which can be isolated.
将其与水蒸气混合，一氧化碳可以转化为二氧化碳，进而被隔离出来。
The leftover hydrogen gas is then used as energy to generate electricity, so there's an added bonus.
剩下的氢气就可作为发电的原料，一举两得。
A third technique exposes coal to pure oxygen, instead of burning it in air.
第三个技术是在纯氧中燃烧煤炭，而不是在空气中。
This creates exhaust gas with higher concentrations of carbon dioxide,
这会释放高浓度的二氧化碳，
which makes it easy to isolate and to banish to the chasms below.
使得碳的分离变得简单。
All this can reduce emissions at a power plant by up to 90%,
这最多可以减少90%的碳排放。
but as with any superhero struggling with their destructive powers,
但正如任何一位超级英雄挣扎着克服自己黑暗的一面，
it takes a lot of effort to switch over from the dark side.
从黑暗面中解脱出来非常困难。
So these positive pollution-busting forces, although they're available,
所以这些解决方案，尽管可行，
have barely been used in commercial power plants because they cost a lot.
但在商业发电厂几乎没有被采用，因为实在太贵了。
But ultimately, the bigger problem is that in most parts of the world,
但最终，最大的问题是在世界上大部分的地区，
it's still too easy and much cheaper to keep emitting carbon dioxide,
放任二氧化碳排放依旧是非常简单而且廉价的方法，
and that makes it tempting to completely ignore coal's dark side.
使得人们倾向于完全忽视碳的黑暗面。
In this case, the most powerful force for good is regulation,
在这种情况下，最有效的方法就是制定规范，
the rules that can restrict the amount of carbon dioxide emitted from power plants,
限制发电厂的二氧化碳的排放，
and make energy companies around the world wary of what they put into the air.
使得全世界的能源公司明白他们往空气中排放了什么。
Until then, every time you turn on a screen or flick a light switch,
直到那时为止，当你每一次打开荧幕或点亮灯泡时，
coal is lurking in the background, carrying its dark powers with it wherever it goes.
煤炭都潜伏在背后，带着他的黑暗能量走向各处。