Stanford biologist Paul Ehrlich passed away in March at age 93. Fortunately, he lived long enough to see his most famous predictions proven wrong. In 1968, he and his wife, Anne, wrote the bestselling “The Population Bomb,” a book that opened with a startling claim: “The battle to feed all of humanity is over. In the 1970s, hundreds of millions of people will starve to death.” Ehrlich had to be happy to see this estimate prove at least 53 times larger than the real tragedy (3.76 million people did succumb to famine). Today, despite 4.76 billion more of us on the planet, the average person’s caloric intake is 30 percent greater than when “The Population Bomb” was published. Moreover, the feat required half as many farmers per person, and, beginning around 2000, a declining share of land dedicated to agriculture.…