ABSTRACT
Among the important human activities which have placed us on a collision course with the rest of the living world, the over-harvesting of natural resources is one of the most obvious. For hundreds of thousands of years, our ancestors’ tiny numbers and simple technologies posed little threat to the supply of most of the useful things that nature and the earth could provide. By around 50,000 years ago, however, following the development of language, advanced tool-making, and complex cooperative behavior, things seem to have changed. Starting with the over-hunting of large game animals, people began to gradually reduce or even completely exhaust many different natural resources: big game animals, high grade deposits of valuable minerals, quality timbers, different kinds of animals and plants, fresh water, and even clean air.1 The greatest drivers of these changes were our increasing numbers, our geographical expansion out of the Old World, and the ongoing march of technology. Population growth created demand for ever larger amounts of more and more varied goods; technological innovation led to ingenious new methods of capturing resources as well as to seemingly endless ways of incorporating them into economically valuable products. Throughout history, numerous natural resources were over-exploited in this way, and many scholars have documented the reduction or exhaustion of one valuable material or another.2
