Kwame Anthony Appiah has a neat Slate piece looking at the curious grip of Malthusian thinking on the literary imagination that also delivers with the secret origins of Soylent Green:
Burgess’ satire came out when global fecundity was nearing its height. A few years later—with a newfound public awareness of pollution and resource depletion—novelists came around to Malthus’ side of the argument. The actuarial balance of terror had shifted. Harry Harrison’s Make Room! Make Room! (1966), a novel of ideas cum police procedural, is set in the year 1999, when New York City has a population of 35 million, and “trembled at the brink of disaster,” seething with food riots, water riots, looting. Animals being pretty much extinct, people make do with steaks made of a soybean-and-lentils concoction known as “soylent.” (The recipe was changed for the Hollywood version, a few years later. “Soylent Green is … legumes!” presumably didn’t test so well.)
It’s worth noting that one oddity here is the continued prevalence of bad math about population density in this genre. The very same book that posits 35 million people living in a super-crowded future New York City involves a global population of just 7 billion. Today we’ve got about 6.8 billion people, New York isn’t substantially more crowded than it was in the mid-sixties, the average American family has more living space than ever before, and Asians are wildly richer than they were 45 years ago. It’s true that the combination of population growth and economic growth are putting severe pressure on the planet’s ability to absorb greenhouse gas emissions, but this is not a problem that’s beyond our technical (as opposed to political) capacity to solve.
Of course this still leaves the philosophical issue: What if Malthus were right? Suppose we could snap our fingers and increase world population to 50 billion at the cost of a drastic reduction in average living standards. Does the aggregate increase in human life outweigh the decline in the average? Derek Parfit famously argued that it did, but it goes against a lot of people’s intuitions.