mental conservation and economic activities are substantially intertwined; and that without global collaboration a healthy, sustainable biosphere is not possible.
Looking back on the historical development of the environmental movement during the twentieth century, it is apparent that the world has partially shifted itself in a new direction. That is not to say that a Chernobyl-like accident could never reoccur, that people will never be exposed to a cancercausing substance, that no species of wildlife will ever become extinct, that any natural environment will never be exploited, or that global climate change will not occur. There is a great deal of work yet to be done on these and many other environmental concerns. As the needs and goals of the global community change in the twenty-first century, new environmental issues no doubt will emerge to be reckoned with, and new environmentalists and organizations will arise to meet those challenges.