Through the '60s, concern increased as the legacy of the unconstrained development made itself felt in urban smog, fouled waters and denuded lands throughout the industrial world. Behind the Iron Curtain, heedless pollution cursed generations of Russians and East Europeans with premature mortality. In the U.S. the late Robert Kennedy once looked at the stew of sewage and refuse floating by in the Hudson River and remarked, "My God, if you fall into that, you won't drown, you'll rot!" In June of 1969 the Cuyahoga River near Cleveland, Ohio, caught fire, and the absurd image of a burning river brought home to the American people that something was seriously wrong with business as usual.

The seemingly endless litany of environmental woes left both scientists and ordinary citizens worrying that the end was near. In 1968 Cornell ecologist Lamont Cole speculated that the ever-increasing combustion of fossil fuels would catastrophically lower oxygen levels in the atmosphere. Biologist Paul Ehrlich forecast that smog would kill tens of thousands in the U.S., that massive famines would sweep India and that by 1979 the oceans would succumb to the cumulative insults of toxic runoff and overfishing. A Time essay in 1968 warned: "At this hour, man's only choice is to live in harmony with nature, not conquer it."