"The energy scientist Vaclav Smil [has calculated](https://www.google.com/books/edition/Enriching_the_Earth/G9FljcEASycC?hl=en&gbpv=0) that fertilizer from the Haber–Bosch process is responsible for about 40 percent of the world’s dietary protein. Roughly speaking, this is equivalent to feeding 40 percent of the world: about 3.2 billion people. More than three billion men, women, and children — an incomprehensibly vast cloud of dreams, hopes, and fears — owe their existence to two obscure early-twentieth-century German chemists and the fertilizer industry they spawned." (Charles C. Mann, Breakfast for Eight Billion)