(WARNING: Spoilers ahead, obviously.)
In Avengers: Infinity War, Thanos shifts from the Mad Titan of the comics who wants to impress Death, who is a literal character you can talk to (and be serenaded by, if you’re Deadpool) in the comic books. In the movie, he’s collecting the Infinity Stones because he thinks intelligent species inevitably overpopulate their planets, putting an impossible strain on resources, leading to famine, war, disease, and other social ills. Even better, Thanos thinks, to just make the deaths happen all at once and let the lucky half move on with their lives. And, while nobody in real life is arguing to kill off half the planet right now, Thanos touches on a real-world problem — a lot of people believe we need to limit the number of humans in the future, and worryingly, they might be right.
We already do this, of course, just not to people. Deer, for example, are often hunted in a way to reduce overall populations when there’s strain on their food supplies. When invasive species show up, scientists are forced to admit that taking a “kill ’em all” approach works, which is why New Zealand has a bunny hunt every Easter, and there’s an ongoing “Eat The Enemy” campaign declaring open season on unwanted, invasive species. Not many people are terribly enthused about this, no matter how delicious the species may be, but from the perspective of, say, a lionfish, we’re Thanos.
But, bar any Soylent Green-esque scenario, we’re not snacking on the neighbors, so how does this apply to humans? Much of the philosophy around this is about avoiding ever asking that question. This is why Bill Gates shelled out six figures for a better condom, and why he and his wife Melinda are promoting family planning initiatives in the developing world. Family planning tools have a lot of benefits for the developing world, including allowing families with limited resources to better support their kids. Other people take this just a wee bit further, in the sense that they refuse to have children at all, in what’s called the “Voluntary Extinction” movement. Others are focused on creating a fairer resource system. With the right distribution of resources, the Earth can support the current human population. It’s just our distribution networks are inefficient. Fix them, or use new technologies to make it easier to grow food, and it’d solve a lot of problems.
That said, human population growth shows no signs of stopping, even if we are, as a species, popping out fewer kids overall. Humans are at the top of the food chain, we’re relentlessly outsmarting the diseases that used to wipe out massive numbers of people (and thus living longer), which leads us to the awkward point that the only thing keeping humanity in check is, uh, us. So if there’s just too many people, then what?
Nobody is proposing a Thanos-esque solution, but it’s also a question with no real answer, and there’s no appetite to find one. Right now, it’s a race: Can we keep coming up with enough social, technological, and medical innovations to keep enough resources in front of enough people to prevent human misery? Or will climate change and geopolitical strain catch up with us?
This is a race we might win, for the record. This is a bit grim to say, but part of the issue is a post-World War II population bump, a bump so big that by 2050 17% of the world’s population will be over 65. So once that generation passes on, not that we’re rooting for your grandma to die, that’s going to free up some breathing room, at least for a while. Similarly, as medical technology advances, family planning will become easier, cheaper, and more effective, so the overall human fertility rate might drop faster than we expect.
Still, the key word here is “might.” Nobody is ever going to seriously propose what Thanos does with the Infinity Stones. But he is right in one way; the only force that decides whether we overpopulate our world or achieve balance with our planet is us, and we need to start making those decisions before political pressures and scarce resources make it for us.