Numbers Don't Lie: 71 Stories to Help Us Understand the Modern World

by Vaclav Smil

With little less than 100 gigajoules per vehicle, the 75 million vehicles sold in 2020 embody about 7 exajoules of energy (slightly more than Italy’s annual energy use) and weigh about 100 million tons. New cars thus weigh more than 180 times as much as all portable electronics, but require only seven times as much energy to make. And as surprising as that may be, we can make an even more startling comparison. Portable electronics don’t last long—on average, just two years—and so the world’s annual production of these devices embodies about 0.5 exajoules per year of use. Because passenger cars typically last for at least a decade, the world’s annual production embodies about 0.7 exajoules per year of use—which is only 40 percent more than portable electronic devices! I hasten to add that these are, necessarily,