These fertile but geographically limited river valleys changed the way people got enough to eat:

It becomes possible for a fifth of a society’s population to grow enough food to feed everyone.

the world consumes absolutely vast quantities of concrete: five tons per person, per year.

the more ordinary people are able to produce, the more powerful people can confiscate.

To create those conditions on a scale sufficient to produce 160 million tons of ammonia a year—the majority of which is used for fertilizer—the Haber-Bosch process today consumes more than 1 percent of all the world’s energy.5

they didn’t shape it by just producing more stuff, more cheaply. Each invention tugged on a complex web of economic connections.

many more people currently own a mobile phone than a flushing toilet.9

The moldboard plow cuts a long, thick ribbon of soil and turns it upside down.8 In dry ground, that’s a counterproductive exercise, squandering precious moisture. But in the fertile wet clays of Northern Europe, the moldboard plow was vastly superior, improving drainage and killing deep-rooted weeds, turning them from competition into compost.

skyscrapers. But here’s the problem: if cheaply made, it will rot from the inside as water gradually seeps in through tiny cracks in the concrete and rusts the steel. This process is currently destroying infrastructure across the United States;* in twenty or thirty years’ time, China will be next. China poured more concrete in the three years after