[00:00:01]The poles are permanently capped with ice.

冰天雪地是两极永恒的主题

[00:08:21]Nowhere is colder,

对于生命

[00:10:55]windier or more hostile to life.

那里的酷寒 狂风是最严苛的挑战

[00:17:55]I'm standing at the North Pole -

我的脚下就是北极点

[00:20:44]the very top of the Earth.

世界之巅

[00:23:43]Up here, it's easy to see

为何极地地区如此寒冷

[00:26:15]why the polar regions are so cold.

身临其境时 体会更加深刻

[00:29:22]The sun never rises high enough in the sky to warm my back

太阳的直射角度很小 鲜有阳光照射下来

[00:35:11]and those rays that do strike the surface

而即使光线到达了地表

[00:38:33]are mostly reflected back from this great whiteness.

大部分也会被这白茫茫的冰雪反射回去

[00:43:42]But the fundamental problem is that there's no sun here at all

但最重要的问题是 这里有半年的时间

[00:49:14]for half the year.

完全没有阳光照射

[00:52:08]The polar winter is unrivalled in its harshness.

极地冬季的严酷 无与伦比

[00:56:07]A night that lasts for months.

一个夜晚可持续数月之久

[01:00:06]Only the toughest stay, as temperatures plunge

随着温度骤降到零下70摄氏度

[01:03:22]to minus 70 degrees centigrade.

只有最顽强的生命才能存活下来

[01:06:00]And yet, the greatest challenge to life here is not the cold,

然而对于生命来说 最大的挑战并非寒冷

[01:10:49]but the extreme swings between the seasons.

而是剧烈的四季更迭

[01:15:58]When the sun finally returns,

当太阳再次升起时

[01:18:43]an extraordinary transformation begins.

一次翻天覆地的转变开始了

[01:21:08]This frozen world begins to melt away.

这个冰冻的世界开始融化