for more than a fifth of the total footprint. (Fossil fuel use and food production are other major components.) And other research implicates materials even more heavily. When measured by weight, materials account for 44 percent of the United States resource use, 58 percent in the case of Japan, and as much as 68 percent in Germany (Gardner & Sampat, 1998; Wackernagel & Rees, 1996).