喻指一定规模的核战争产生的烟尘遮蔽地球表面而造成的气温骤降，生物大规模灭绝，犹如冬天的灾难性气候nuclear winter

• “核冬天”理论基本假说

  fundamental hypothesis of the "nuclear winter" theory

• 核战争之后的人类世界，进入了数百年周期的核冬天。

  After a nuclear war, the human world would enter a nuclear winter with a cycle of several hundred years.