被点亮的星球（2018）

When we discovered the hole in the ozone layer,
当我们发现臭氧层空洞时
mankind did come together on that one and we banned those substances.
人类共同努力 禁止有害物质的使用
漫游太空143天
杰瑞·林恩格
You look down and you see this fragile planet
你低头 就能看见这脆弱的星球
which supports life on its surface in the face of the incredible hostility
它面对着极度的危险仍孕育着生命
and so you become much more sensitive,
你会变得更加敏感
I think, to the need to protect it.
它也需要保护
Any way you look at it, the ozone layer is pretty special.
不论怎么看 臭氧层都很特殊
This shield has looked after us for millions of years,
这层屏障保护了我们几百万年
even before mankind came down from the trees,
在猿猴进化成人之前
even before the dinosaurs walked the earth.
甚至在恐龙存在之前
Without the ozone layer there would be no human race.
没有臭氧层就不会有人类
Life on earth would be trapped under water.
地球上的生命将只限于水中
In Earth's battle with the sun,
在地球与太阳的斗争中
the sun has often had the upper hand.
太阳总是占上风
Today the ozone layer protects us from UV but once upon a time,
现在 臭氧层保护我们免受紫外线伤害 但很久以前
it wasn't there.
它并不存在
The only safe place for life was under the waves.
唯一适合生命的安全地带在水下
Life would probably still be down there if it wasn't for something
如果三十亿年前没出现一个可以
new that emerged nearly three billion years ago
将阳光作为己用的新物种
and found a way to use sunlight to its advantage.
生命也许现在还只能在水下
Billions of years ago as ancient organisms first harnessed the energy of the sun,
几十亿年前 当远古生物首次利用太阳光能
漫游太空50天
杰夫·霍夫曼
they began producing a waste product.
它们开始产生一种代谢废物
Oxygen.
氧气
At first it was just a few individuals, but thousands became millions.
开始只是很少的个体 然后几千个变成几百万个
Millions became trillions.
几百万个变成数万亿个
All bubbling up oxygen.
全部生产着氧气
When oxygen gas rises high into the atmosphere
当氧气上升到大气中时
something very special happens to it.
神奇的事情发生了
It transforms into protective ozone.
它转化成了有保护性的臭氧
Under the shelter of this ozone layer, first microbes
在臭氧层的保护下 先是微生物
then fungI and plants migrated out of the water.
随后真菌和植物都从水中迁出
And this meant even more oxygen was being produced,
这意味着更多的氧气正在被制♥造♥出
further strengthening our shield against the sun's UV light.
进一步加强了对紫外线的防护层
And this would help make possible one of our planet's
这将成为我们地球上
most defining moments.
最重要的时刻之一
Protected by a thicker ozone layer than ever before,
由于被厚度前所未有的臭氧层所保护着
a whole new world of possibilities opened up for life on earth.
地球向生命敞开了新世界的大门
We think it was about 400 million years ago when
我们认为 当四亿年前
simple vertebrates first took their tentative steps onto dry land.
初等脊椎动物蹒跚在干燥的陆地上时
It's probable that these early animals were moving around
或许这些早期动物仍通过
using something that was still pretty much like the fins
类似鳍的东西行走
that they used to get around in the water.
就像以前它们在水里一样
With that one small step from water to dry land...
从水里迈向陆地的那一小步
life on earth changed forever.
地球上的生命自此产生巨变
That was one small step for animal kind
那是动物的一小步
and one giant leap for life on earth.
但却是地球上生命的大飞跃
Life spilled out of the water in a billion different ways
生命以数以十亿计的方式离开水
taking on a host of forms.
以各种形态来到陆地
All because of that special layer of oxygen up in the sky.
一切都源于天空那层特别的氧气
Right, so that's two shields that our planet gives us.
是的 那是地球给予我们的两层护盾
But the sun has a final weapon.
但太阳有终极武器
Heat.
热量
It's pumping out millions of degrees of powerful burn
太阳迸发着上百万度的强力高温
and that powerful burn is intensified by an ally down here on earth,
这种强力高温还被它的地球盟友强化着
one feared by people everywhere.
人人都惧怕它的地球盟友
印度尼西亚
布罗莫火山
Volcanoes make terrible neighbors
火山是糟糕的邻居
but even if you live far away from one,
即使你的住处远离火山
like on the other side of the planet,
比如住在地球的另一端
a volcano could still make you feel the heat.
你依然能感受到火山的热量
Much of this gas cloud is CO2, carbon dioxide,
这些气体中大部分是二氧化碳
and CO2 is a killer.
它是无情的杀手
It traps heat in the atmosphere.
它将热量困在大气层中
If you wanna know how dangerous CO2 can be,
如果你想知道二氧化碳的危险性
just try taking a walk on Venus.
在金星溜达一圈便知道了
The surface of Venus is hotter than hell.
金星表面的高温如同炼狱
Surprisingly the planet with the hottest temperature
令人惊讶的是 在太阳系里
漫游太空166天
查里斯·哈德菲尔德
at the surface in our whole solar system is Venus,
地表温度最高的星球是金星
even though it's not the planet closest to the sun.
尽管它并不是离太阳最近的星球
That is purely the effect of having too much carbon dioxide in your atmosphere.
那纯粹是因为大气层里存在过多的二氧化碳
On earth, volcanoes have been firing CO2 into the sky
地球的火山向空中喷发二氧化碳
for billions of years.
已有上亿年的历史
So, here's the question.
那么 问题来了
How come it's pretty cool here on Earth while Venus is fully baked?
金星热如炼狱 为何地球还能如此凉快
Well, the earth has its own way of dealing with CO2,
地球有处理二氧化碳的独特方法
unique to this planet.
是这颗星球的独门秘诀
But it can easily go wrong.
但它很容易出差错
The sun threatens us with solar explosions and ultraviolet light
太阳风暴和紫外线对人类造成极大威胁
but its most dangerous weapon could be plain old heat.
但最危险的还是极致的热量
It can cook planets,
它能烤熟星球
especially ones wrapped in a warm blanket of carbon dioxide gas.
特别是那些被二氧化碳气体包围的星球
But the Earth has its own very elegant way to stop itself
但地球有其优雅之道
from being boiled dry by the sun.
防止被太阳蒸干
The best way to see it in action is from 250 miles straight up.
看到它的最佳方式是从402公里高处鸟瞰
Just like the human body has ways of keeping all of our systems in check,
就像人体能保证自身系统的正常运作
similarly the earth has its own regulatory system...
类似地 地球也有自己的调节系统
and it's kept just about the right amount of carbon dioxide in the atmosphere.
它只在大气里保留适量的二氧化碳
漫游太空50天
杰夫·霍夫曼
From space you got a unique perspective.
你能从太空中获得独特的视角
The process starts with something
一切始于某种
no other planet in the solar system has.
其他太阳系星球没有的东西
An air conditioning system made possible by rain.
雨水使空气调节系统变成现实
Normally we think of the rain as being pure water
我们通常认为雨水是
coming down out of the sky.
从天而降的纯净水
But actually it's carrying dissolved carbon dioxide from the atmosphere
但事实上 雨水携带着来自大气的溶解二氧化碳
and this makes it acidic enough to dissolve rocks.
雨水变成酸性物质 溶解岩石
Ultimately this water, silt and locked-up carbon dioxide
最终 这些水 泥沙 和封存的二氧化碳
will all get washed into the planet's rivers.
一同汇入地球的河流
This process goes on right under our noses every day
这个过程每天都会悄然发生
but sometimes it can make itself visible in a truly spectacular fashion.
但有时它会以壮观的形式引起我们的注意
中国
小浪底
总工程师
肖♥强♥
These people get to take a small peek at the way
这些人得以一瞥
our world keeps itself cool
我们的地球如何保持凉爽
and, wow, is it impressive.
场面令人叹为观止
Hidden in all that water is carbon pulled from the sky.
藏在水里的是从天而降的碳
This great river is forcing it into the ocean.
这条大河正迫使它流向海洋
Seen from above its raging majesty is laid out for the stars to see.
鸟瞰此景 仿佛是在向星空展示其愤怒雄壮
Looking at rivers from space
从太空鸟瞰河流
you really get a sense of the movement of huge amounts of material.
你能确切感觉到大量的物质流动
It's unforgettable.
难以忘怀的场景
You can see the brown color which goes way,
你能看到奔流的棕色河流
way out into the ocean.
一路奔向海洋
As rivers spit out huge quantities of sediment and locked-up CO2,
当河流带走大量的沉积物和封存的二氧化碳
carbon that was once in our atmosphere
曾存在大气里的碳
gets buried at the bottom of the ocean
被深埋在海底
and that helps cool down our planet.
这个过程有助于冷却地球
Over millions of years the cycle of rain, rivers and volcanoes
数百万年间 雨水 河流和火山之间的循环
has helped balance the CO2 in our atmosphere,
帮助平衡大气层内的二氧化碳量
keeping us warm in the coldness of space
令我们在太空的严寒里得以温暖
while preventing us from being boiled alive by the sun.
也使我们免遭太阳的炙烤
I had studied earth science,
我学过地球科学
but when you actually go into space,
但当你真正飞上太空
you feel it on a visceral level.
你会由衷地感叹
You realize it's the living Earth.
你会意识到这是活着的地球
All of these systems on the planet whether it's,
这颗星球上各种生态系统
you know, volcanoes, whether it's currents in the ocean...
火山 哪怕其存在于海洋身处