地球的力量 第3集 冰川(9)触发全球降温
可见其中的奇怪之处
it seems this warm current is what tipped theplanet into an ice age.
海洋暖流是地球进入冰河世纪的提示
Its warm waters brought more moisture to the coldnorthern regions of the planet
如果暖水带来更多的蒸汽 给地球寒冷的北部地区
so more snow fell, and ice began to build up.
这样会下更多雪
Slowly the Northern Hemisphere iced over,
北半球将会缓慢的被冰雪覆盖
triggering a global cooling.
触发全球降温
In the last million years,
在过去一百万年间
the ice has advanced and retreated 10 times in a cycle,
冰进攻和撤退，超过十次循环
aided by small changes in the Earth's orbit.
由地球轨道的细微变化导致
Although a few million years is just the blink of an eye in the planet's life,
对于地球生命来说数百万年不过是弹指一挥
this recent ice age has had an extraordinary influence on our world, and on us.
最近这次冰河世纪对于我们的世界，对于我们的确有特别的影响
It changed the climate across the planet.
我们发现，它改变了地球的气候
In doing so, it helped drive human evolution.
它的所作所为，推动了人类进化
Most obviously, it physically carved much of the world we know today.
雕刻了我们今天熟知的许多标志性景观
