is heating our planet faster than at any time in the last 500 million years. 正在以五亿年来从未有过的速度 令地球升温
The buildup of ice in the north affected the climate across the planet. 北方冰冻影响全球气候
While ice never completely engulfed the planet, 尽管冰雪从未覆盖整个地球
led to an abrupt cooling of the planet. 导致地球温度骤降
What had been a slow cooling of the planet 过去缓慢的地球降温
Such is the role of chance in the history of life on our planet. 这就是机遇在地球生命历史中 所扮演的角色