We have a tendency to take any trend and extrapolate it far out in the future. This is done for both good and bad trends but bad trends tend to garner greater attention because they predict some kind of catastrophe.
One trend that is noteworthy is that of population growth. In my own lifetime I have seen fears about global populations reverse dramatically, from unchecked growth to problematic decline. In the 1970s, there were alarms that the runaway growth of population would result in a world where we would be crowded into a Soylent Green-like future with ever-smaller living spaces, where there was not enough food to feed everyone, leading to widespread violence and wars over access to scarce resources. One of the primary sources of these fears was the 1968 book The Population Bomb by Paul Erhlich, as recounted in an article by Gideon Lewis-Krauss.
In 1968, Paul Ehrlich, a lepidopterist, and his largely uncredited wife, Anne, published a best-seller called “The Population Bomb.” For centuries, economists had worried that the world’s food supply could not possibly be expected to keep pace with the growing mobs of people. Now there was no postponing our fate. “The battle to feed all of humanity is over,” Ehrlich wrote. “In the 1970s the world will undergo famines—hundreds of millions of people are going to starve to death.” This was the received wisdom of the era: a decade earlier, an only slightly flippant article in Science estimated that in November, 2026, the global population would approach infinity.