In the early 1970’s, the flush of technological optimism was over, the Vietnam War was a disaster, societies were in turmoil, and economies were stagnating. Rachel Carson’s 1962 book Silent Spring had raised fears about pollution and launched the modern environmental movement;
20世纪70年代初，技术乐观情绪不再，越南战争成为一场灾难，社会纷纷陷入动荡，经济则停滞不前。蕾切尔·卡森（Rachel Carson）1962年的著作《寂静的春天》点燃了人们对污染的恐慌，也点燃了现代环保主义运动；保罗·埃尔利希（Paul Ehrlich）1968年的标题《人口炸弹》说明了一切。在1970年的第一个地球日，人们一片悲观。