In the '60s already, through the green revolution of fixing nitrogen from the atmosphere -- you know, human's today take out more nitrogen from the atmosphere than the whole biosphere does naturally as a whole.
60年代通过绿色革命 和固定大气中的氮 的哈柏法-- 你知道，人类今天从大气中提取氮的含量 远远大于整个生物圈在自然情况下所提取的。