Smil thinks that the prospects are uncertain but that human ingenuity could achieve that goal. He points out that modern technology allows us to create ever more value using less and less material. Today, for example, it takes only 20 percent of the energy it took in 1900 to produce a ton of steel. Similarly, it now takes 70 percent less energy to make a ton of aluminum or cement and 80 percent less to synthesize nitrogen fertilizer. Excluding construction materials, Smil calculates that in the U.S. it took about 10 ounces of materials back in 1920 to produce a dollar’s worth of value. That is now accomplished using only about 2.5 ounces, a 75 percent decline in material intensity.

While the ever more efficient use of energy and materials results in relative dematerialization—less stuff yielding more value—the overall trend has been to extract more and more materials from the earth and the biosphere. “There can be no doubt that relative dematerialization has been the key (and not infrequently the dominant) factor promoting often massive expansion of material consumption,” Smil writes. “Less has thus been an enabling agent of more.” For example, the 11 million cellphones in use in 1990 each bulked about 21 ounces for total overall mass of 7,000 tons. By 2011 cellphones averaged about 4 ounces, but the total weight of all 6 billion had increased a 100-fold to 700,000 tons. As increases in efficiency make goods cheaper, people demand more of them.