"The lives of 3½ billion astronauts on board Spaceship Earth are just about as much in peril today as were the men aboard Apollo 13 in 1970. However, the pervasive irony of this analogy is that we... have nowhere else to go... We must begin to treat our spaceship within this context. ...Proper and moderate use of our mineral resources is necessary. Maintaining the correct atmospheric mixture of oxygen, carbon dioxide, and nitrogen is critical. Renewable resources such as minerals, gases, and water must be returned to their cycles in a reusable form. Solid wastes on board... must be efficiently disposed of... in a form that can be degraded by decomposer organisms so that such materials will not accumulate. ...In short, the environment of the spacecraft must be kept orderly, balanced, and efficient. ...[P]otentially, overpopulation is more dangerous than a malfunctioning of... life-support systems... We can restore the craft's environment only if we fully understand not only its processes, causes, and effects, but also all the ramifications of our attempts at restoration... [and] the physical inner-workings of the entire system. ...[T]he current environmental crisis can ultimately be alleviated only by a massive shift in our individual and corporate lifestyles. ...Drastic changes in our economic, sociological, political, moral, ecological, and religious practices and beliefs must occur ...to live in relative harmony... to change our style of living... to that of a spaceman... being, acting, thinking, living, and responding like an astronaut on board Spaceship Earth."