地球的力量 第3集 冰川(9)觸發(fā)全球降溫
可見其中的奇怪之處
it seems this warm current is what tipped theplanet into an ice age.
海洋暖流是地球進(jìn)入冰河世紀(jì)的提示
Its warm waters brought more moisture to the coldnorthern regions of the planet
如果暖水帶來更多的蒸汽 給地球寒冷的北部地區(qū)
so more snow fell, and ice began to build up.
這樣會下更多雪
Slowly the Northern Hemisphere iced over,
北半球?qū)徛谋槐└采w
triggering a global cooling.
觸發(fā)全球降溫
In the last million years,
在過去一百萬年間
the ice has advanced and retreated 10 times in a cycle,
冰進(jìn)攻和撤退，超過十次循環(huán)
aided by small changes in the Earth's orbit.
由地球軌道的細(xì)微變化導(dǎo)致
Although a few million years is just the blink of an eye in the planet's life,
對于地球生命來說數(shù)百萬年不過是彈指一揮
this recent ice age has had an extraordinary influence on our world, and on us.
最近這次冰河世紀(jì)對于我們的世界，對于我們的確有特別的影響
It changed the climate across the planet.
我們發(fā)現(xiàn)，它改變了地球的氣候
In doing so, it helped drive human evolution.
它的所作所為，推動了人類進(jìn)化
Most obviously, it physically carved much of the world we know today.
雕刻了我們今天熟知的許多標(biāo)志性景觀
