ABSTRACT
This chapter looks backward, to the end of the nineteenth century and the beginning of the twentieth century. It examines the research others have conducted to identify the historical trends in resource availability during this period, research that begins with the 1870s and then runs through the intervening years to the present. Ultimately, we are concerned about the future, not the past, and past trends, of course, may not continue into the future. Nevertheless, an understanding of the past will prove useful when we turn our attention toward the future in Chapter 5.
