这个纪录片探讨人类活动(human activity)对自然界造成的影响，呼吁我们要控制全球变暖(global warming)，减少温室气体的排放(emissions of greenhouse gases)，英文解说用词相对简单，句子构造可以拿来借鉴一下，学英文的同时也要提高环保意识(environmental awareness)哦。废话少说，开始上图！
Our Planet
我们的星球
Since then, the human population has more than doubled.
从那以后，人口已经增长超过两倍。
For generations, this stable Eden nurtured our growing civilizations.
经过多少代，这个安定的伊甸园滋养着我们的文明成长。
In the past 50 years,
wildlife populations have, on average, declined by 60 percent.
过去五十年以来，野生动物的数量，平均来说，已经减少了60%。
Never has it been more important to understand how the natural world works,
and how to help it.
了解自然界如何运作和如何拯救自然从未像现在这样如此重要。
All in this immense assembly are here
because a powerful oceanic current, the Humboldt,
sweeps up from the Antarctic,
bringing with it rich nutrients from the ocean's depths.
它们都出现在这庞大的饕餮盛宴中，这是因为一股强大的洋流，洪堡洋流，横扫南极，从海洋深处带来丰富的营养物质。
Water evaporating from the surface of the sea
condenses to form great clouds.
从大海表面蒸发出来的水分冷凝成大大的云。
They build mounds of mud that raise up their eggs
and so keep them just marginally cooler than they would be at ground level.
为了孵蛋，它们筑起淤泥土堆，这样能保持鸟蛋稍微比地面凉快些。
Playing strengthens its legs for the long journey that lies ahead.
玩耍锻炼它腿部力量，为前面的长途跋涉做好准备。
The dogs have incredible stamina...
The mother blocks the dogs, shielding her calf.
这些狗有着惊人的耐力。
这个妈妈为了保护小牛，挡住了那些狗。
The relationships between them all are multitudinous and complex.
Plants often depend on animals to pollinate their flowers.
Male orchid bees need a rich perfume with which to impress their females,
and the orchids provide it.
所有它们（热带森林里的动植物）之间的关系形形色色，也很复杂。
植物经常需要动物帮忙给花朵授粉。
雄性兰花蜜蜂需要一个强烈的香味以此来吸引雌性蜜蜂，兰花能提供这个香味。
The most complex routine is that developed by the blue manakin.
The dance has to be perfectly synchronized.
The lead male performs the final move.
Have they done enough?
最复杂的舞蹈动作是由蓝色侏儒鸟跳出来的。
这个舞蹈必须保持完美同步(三个鸟一起跳舞)。
领头的雄鸟完成最后的动作。
它们跳地到位吗？
The forests are a crucial refuge
for the relatively few species that are able to survive here.
The forests will give some protection from the worst of the weather.
森林对于那些相对稀少的物种来说是个重要的庇护所，这儿能让它们生存下来。
森林会在天气最恶劣的情况下提供保护。
And in the winter, they specialize in hunting caribou.
They move fast by avoiding the deep snow,
sticking to the hard-packed trails made by the caribou.
冬天它们专注于猎食驯鹿。
它们快速移动，避免陷入深雪中，紧贴在被驯鹿踩实的小道上
They will travel 600 kilometers, crossing mountains to reach the tundra,
where the spring grass will be sprouting again
and they can give birth.
它们将会行走600公里，穿过山川，到达冻原，在那儿，春天草地将会再次冒出新芽，它们将在那里生育。
Though they may seem remote to many of us,
the stability of these icy wastes is crucial to all life on the planet.
But in just 70 years, things have changed at a frightening pace.
虽然它们（南极和北极）似乎离我们很遥远，这些冰原的稳定性对地球所有的生命起到至关重要的作用。
但是在过去70年里，情况在以骇人的速度变化着。
The polar regions are warming faster than any other part of the planet.
The Arctic in the north is a frozen ocean,
and the sea ice on which all life here depends,
is disappearing.
极地地区变暖的速度超过地球任何其它部分。
位于北部的北极是个冰冻的海洋，所有生命赖以生存的海冰正在消失。
This glacial ice, together with the sea ice,
protects our planet by reflecting solar radiation away from the surface
and so preventing the Earth from overheating.
这个冰川上的冰和海冰一起保护我们的地球，它们能从表面反射太阳辐射，防止地球变得过热。
Glaciers have always released ice into the ocean,
but now this is happening nearly twice as fast
as it did ten years ago.
冰川一直都在往海洋里释放冰块，但现在释放的速度接近于十年前的两倍。
Around the world, ice is now feeding vast amounts of fresh water into the sea,
raising sea levels, changing salinity and disrupting ocean currents.
全世界范围内，这些冰往海里注入了大量淡水，提升海平面，改变海水盐度，还扰乱洋流。
What we do in the next 20 years
will determine the future for all life on Earth.
我们在接下来20年所做的事，将会决定地球所有生命的未来。
看到这里，有没有碰到喜欢的句子呢，直接记在笔记本上吧！
