Approaching the Task
Human history could usefully be written by tracing the growth of the impacts people have on the world around them. In the beginning, humans were a negligible factor. Their number was small, and they had precious few bits of knowledge and capital with which to alter their surroundings. If they had disappeared from the earth at that stage in history, few traces of their presence would have remained after a few years. Today, the consequences of human actions stretch over vast areas of space and time. The most obvious and dramatic example is the power to send sufficient destructive power from one side of the globe to the other to destroy regional, if not global, ecological balances for centuries to come. But this is a potential impact; the majority of examples have to do with long-term, pervasive influences that occur on a daily basis: the accumulation of capital and knowledge along with that of carbon dioxide and carcinogens; the dedication of land on a more or less permanent basis to such uses as dams, cities, power plants, and nuclear storage sites; the increasing density of population per unit of land; and the depletion of lowcost energy and mineral deposits. All such results of human activities, for better and for worse, are part of the increasingly important bequest we leave to future generations.
Although these impacts have undoubtedly grown over time, the ability to take them into account in making decisions has not grown apace. Some would explain this growing gap by the human's tendency toward shortsightedness and indifference to events of less than immediate concern. Others would emphasize the inability to control the collective actions of the species. But the principal problem must be ignorance, the sheer inability to assess the longer run impacts of a given action in any realistic way. Without such knowledge, meaningful concern and effective efforts at control are not possible.