Vaclav Smil has calculated that fertilizer from the Haber-Bosch process was responsible for “the prevailing diets of nearly 45% of the world’s population.” Roughly speaking, this is equivalent to feeding about 3.25 billion people. More than 3 billion men, women, and children—an incomprehensibly vast cloud of dreams, fears, and explorations—owe their existence to two early-twentieth-century German chemists.
