by Casey terHorst

The Avengers: Infinity War is now playing in theaters. 

(no spoilers here beyond what’s in the movie trailer)

One of the cool things about recent Marvel movies is that the motivations of the “villains” are not purely selfish or evil, but rather they are focused on righting a wrong. For example, in Black Panther, Killmonger wants to end the oppression of Black people around the world by arming them with the most sophisticated weapons. What makes the movies compelling is that it’s easy to sympathize with the motives of the villain, even if we don’t agree with their drastic methods. It also makes us think about what we can do now to solve the problem at hand, before such drastic methods are necessary.

The same is true of The Avengers: Infinity War. I won’t reveal any spoilers here other than the motivation of the villain, but if you’ve seen the trailer, you already know that. And judging from the crowds at the movie theater the last couple weekends, if you haven’t already seen this movie, you’re in the minority.

Our villain in this movie understands ecology pretty well and I argue that we should consider his motivation as an ecologist, rather than as an act of evil. Thanos has appeared in a bunch of different Marvel comics and has been teased in Marvel films before. Unlike many villains who seek power only for themselves, Thanos has studied the Universe and recognizes that the population is close to exceeding the number of resources available to support that population. His solution: instantaneously reduce the population size by half. He proposes to do it randomly, so that no group of people will be favored more than others. His rationale is that the remaining people will lead better lives with more resources available to them.

The existence of a carrying capacity (K) is one of the fundamental principles we teach in undergraduate ecology courses. Populations are density-dependent. Fine, we can argue about how often natural populations are actually affected by the carrying capacity, but K exists at some level for every species. One question that always comes up in class is “how close are humans to K?”. There is evidence that humans are approaching K, though others suggest that better technology and innovation will keep pushing K higher and higher.

When students first start studying population dynamics, they learn that K is an equilibrium point towards which all populations are headed, which makes it seem like a super happy fun place. Equilibrium. That sounds great, right? Everything is balanced. It sounds peaceful. But I try to impart to my students that K is a REALLY bad place to be. It means every individual is just barely getting by. There are a lot of deaths and those individuals who live aren’t thriving. They’re constantly hungry and crowded. In short, we can debate whether humans are getting close to K or not, but the bottom line is that we don’t want to be anywhere near our carrying capacity.

Ecologists and conservationists have recognized a number of threats to humans and other species on our planet: climate change, deforestation, habitat fragmentation, food shortages, overfishing… and the list goes on. Overpopulation lies at the root of all of these problems. There are few problems in the world that wouldn’t be more easily solved if there were fewer people on the planet. So in that sense, Thanos has it right. As an objective ecologist, the quickest way to solve a huge number of problems would be to wipe out half the population.

Now obviously I don’t think ecologists should become advocates for mass murder. No person in their right mind is going to actually advocate killing people randomly (or non-randomly for that matter). But we should spend A LOT more time talking about how we can slow population growth. We should be talking about having fewer kids. It’s sound ecology.

Yes, I’ve heard the argument that you’re going to have kids that are good environmental stewards. But will their green lifestyle have less carbon footprint than their non-existent counterpart? NPR had a great story about the ethics around whether or not, as a conservationist, it makes sense to have kids. Consider this: if you stop driving, eat vegan, recycle, and fly less, you could save 5 metric tons of carbon per year. Note, that’s only if you’re a very good citizen…and most people aren’t. But let’s say you put in this huge effort and make it work, at a significant cost to your own happiness…then the world gets a huge payoff in carbon credits. If you choose to have one fewer child, you save 58.6 metric tons of carbon per year. That’s 10 times the benefit EVERY YEAR for doing nothing at all.¹

We don’t talk about these numbers nearly enough, because it’s taboo to tell people not to have kids. But I’m going to say it anyway—stop putting more people on this planet. We don’t have to stop having kids entirely; that would be impractical. But if every couple had one fewer child than the current average, population size would stabilize. So maybe have one kid instead of two? Two instead of five? Let’s avoid getting any closer to the carrying capacity and avoid getting to the point where we need to debate whether Thanos’ solution is ethical or not.

¹https://www.theguardian.com/environment/2017/jul/12/want-to-fight-climate-change-have-fewer-children

Author biography: Casey terHorst is an assistant professor at California State University, Northridge. He is a community ecologist and evolutionary biologist focused on what affects diversity, both in nature and in STEM fields. You can find him on Twitter (@ecoevolab).

Image credit: Image from Wikimedia Commons.