宇宙（2007）

The Universe S01E06

Part 5 April 22, 2021, 8:11 p.m.

逐渐融化消失
The Earth's North and South Polesare known as the cryospheres,
地球的南北极众所周知的
regions blanketedwith snow and ice.
拥有大量冰雪
They help regulate climate temperatureand water levels around the globe.
调节着地球气温与水平面
NASA Senior Scientist,Waleed Abdalati,
NASA 科学家 Waleed Abdalati
investigates the frozenparts of our world.
调查世界上的冰冻区
The feeling of being on the iceis amazing.
站在冰上感觉很奇妙
It's pristine...
非常荣幸的能够踏上这些地方
in places where probably my bootshave been to touch the ground there.
这就是我第一次站在冰面上的感受
It's very humbling...
会觉得自己很渺小
You stand there and it's so vastand impressive...
站在那儿,你感受到一种巨大,非常难忘
But in the last century,
但是最近一个世纪以来
scientists like Dr. Abdalati
科学家们,比如 Abdalati 博士
have personally witnessedEarth's ice shrinking.
证实了冰层的消失
The reason: ice and snoware white,
原因是白色的冰雪
they reflect sunlightand cool the planet.
反射阳光冷却地球
By contrast, the open oceansabsorb sunlight,
相对的,海洋吸收阳光
which heats the globe.
温暖地球
However, as ice melts,it creates more open water
然而,融化的冰产生了更多水
which sucks in more sunlightand increasingly warms the planet
吸收了更多阳光使地球更温暖
and melts more ice.
然后又融化更多的冰
It's unstable, we say,
我们说这是不稳定状态
because even the slightest change
即使一个小的改变
tends to amplify itself.
也会带来巨大变化
And it's essentiallya runaway effect.
很典型的恶性循环
Earth's polar ice capsare in peril.
地极现在很危险
Continually melting ofthese precious landscapes
这些持续融化的宝贵风景
may one day producecatastrophes across the planet.
也许会在某个时刻带来灾难
At the South Pole,the continent of Antarctica,
在南极
holds 70% of the world's fresh water.
那儿拥有世界70%的淡水
Ice shelves surrounding the continenthold back ice like the Hoover Dam.
这些大♥陆♥边缘的冰保护着内部的冰
就像胡佛大坝那样
But they are weakening.
但是现在很脆弱
After 12.000 years of solidity
已经存在了超过12000年的
the Larsen B Ice Shelf collapsedin just 5 weeks.
Larsen B 冰层仅仅在5周时间就坍塌消失了
At the North Pole,
在北极
some predict that the Arctic Oceanwill be ice-free during the summer
有人预言,北冰洋夏天将不再结冰
in the next 40 to 60 years.
也许仅仅只是40-60年之后
What's causingthe warm temperatures
这样的高温到底是如果产生的?
certainly there抯 an elementof natural variability,
一部分地,有自然自身的变化原因
but there is also a human contribution.
但是人的作用更不可忽视
We know that humans arecontributing to the warmer environment
我们知道,人类促使全球气温上升
and that we're subsequentlycontributing to diminish ice cover.
这加速了冰层的消失
In Greenland,the Jakobshavn Glacier,
在格陵兰岛, Jakoshavn冰川
one of the fastestflowing glaciers in the world,
世界上流动最快的冰川
is now moving likea runaway train.
就像运行着的一列火车
So it's now going about
现在,它快速运动着
5 ft/hour, which believe me,for a glacier is very fast.
每小时5英尺
The worst-case scenario would bethat all of these glaciers
最糟糕的情况就是所有冰川
start to speed up and just deliverhuge amounts of ice to the sea.
越来越来地流失,大量的冰流入海中
That would be a 3-footincrease worldwide.
这将提升海平面差不多3英尺
And 3 feet in coastal regions
在海岸临近区域,3英尺意味着
is plenty to displace millionsand millions of people.
冲击至少千万计的人类
Although humans may be ableto stabilize
虽然人类可以迁移到稳定地区
man-made pollutants,it might take decades.
但是人类制♥造♥的垃圾,最多几十年
At the same time,there are natural processes at work
这时,自然界的破坏就将起作用
that might determine mankind's fate.
决定人类的命运
The planet's goingthrough its own evolution.
地球会一直进行自身的发展进化
What we do to the planet affects us,it doesn't affect the planet.
我们对地球的所做,只会影响我们自己,而非地球
So we may mock upwith the atmosphere
我们可以建一个大气的模型
for a few thousand years ofglobal warming and so forth,
上千年的全球变暖之类
but this is actually just a blip.It's an important blip to us,
事实上这只对人类而言很重要
but it's not necessarily a blipin terms of planetary evolution.
对于行星自身发展不重要
Donald Brownlee and colleague Peter Ward
Donald Brownlee 和 Peter Ward
have measured our planet'svital signs,
测量了一些地球上生命赖以生存的信♥号♥♥
and its prognosis it's bleak.
预计结果令人担忧
Earth, as a place for animaland human life,
地球作为动物和人类的生存之地
is nearing old age.
开始进入老年时期
Why?
为什么?
Our Sun is getting brighterand hotter.
太阳将越来越亮,越热
The problem down the linefor advanced life on Earth
地球上高等生物面临的问题
is that as the Sun getsslightly brighter,
是因为太阳变得更亮了些
the expectation is
假设
that carbon dioxide will be almostcompletely removed from the atmosphere.
完全去除大气中的全部二氧化碳
There will be an endto the age of plants and animals.
这会导致地球动植物的灭亡
Humans could die out500 million years from now
人类也将在500万年内灭亡
due to the brighteningof the Sun.
因为越来越热的太阳
But in the grand schemeof things
但是,在一些完美计划下
Man may have had a good run.
人类或许能顺利发展
Before reaching extinction,
躲过灭亡的命运
perhaps humans will have livedlonger than any other complex species
人类将可以生存在更复杂的环境下
because of their ability to adaptto changing environmental conditions.
通过自身努力改变自然环境
From a human standpoint,
从人类视角来看
the Earth will remain been a Porscheplanet probably for another...
保时捷中的地球司机像其它行星将继续行驶
half a billion to a billion years.
5或10亿年时间
Which is a truly awesome timescale
这个时间单位
from a human standpoint.
对于人类实在太长了
As Spaceship Earth manoeuvresthrough uncharted waters,
通过利用地球上
来历不明的水
humankind can reflect on the planet'sawesome achievements
人类思考着地球诞生的奇异之处
and steadfast survival
地球自身,又坚毅地生存于
in the tough neighbourhood
荒凉的邻空
called THE UNIVERSE.
这就是宇宙