The "circularity gap," as de Wit and his colleagues dubbed it when they presented their report at the World Economic Forum in Davos in 2018, is relatively new in human history. It dates to our industrial use of fossil fuels in the 18th century. Until then, most of what humans did was done with muscle power, whether human or animal. Growing things, making things, shipping things took hard labor, which made them valuable. Our limited physical energy also restricted how big a dent we could put in the planet. It kept most of us very poor, however.

Cheap fossil energy, concentrated by geologic time and pressure in seams of coal or pools of oil, changed all that. It made it easier to extract raw materials anywhere, ship them to factories, and send the merchandise everywhere. Fossil fuels exploded our possibilities -- and the process keeps intensifying. In the past half century, while the world's population has more than doubled, the amount of material flowing through the economy has more than tripled.