Article Summary

  • Around 74 billion land animals are killed by humans for food each year, and another 1 to 3 trillion fish are killed each year. In total, we could say there are somewhere around 1 trillion animals killed by humans each year for food.
  • Although that’s a big number, the majority of all animals ever killed by humans could exist in the future, especially if our current trends continue. If we assume that humans continue their current animal consumption for another 1,000 years, then almost all of the animals who will ever be killed by humans haven’t been born yet.
  • Since we care about all animals, we need to make sure our impact helps animals in the future—either by ensuring that they don’t exist (vegan world), that they’re born into a life free of exploitation (sanctuaries), or at the very least that their suffering is as minimal as possible (high welfare).
  • To impact animals in the future, we need to:
    • Keep the far future in mind;
    • Make our impact global;
    • Make our impact structural; and,
    • Make our impact resilient to societal disruption.

If we care about animals, then we need to take the big picture into account.

In this article, we’re going to be thinking about our impact over all time—in other words, how our work affects animals who might exist in the future.

Animals Killed Each Year

First, let’s get some numbers for how many animals are killed each year. There are around 56 billion land animals killed each year for food globally, and the majority of them are chickens. There are also 1 to 3 trillion fish killed each year for food by humans each year (including bycatch, feeder fish, etc.). Over half of all animals killed for food are killed in China.

These numbers aren’t perfectly precise, but they give us a sense of the scale.

Looking Into The Future—But First, Math

But now let’s factor in the role of time: how many animals are killed each year, for all years, past and future.

(Before we start, I want to say that I know these numbers are going to be very rough estimates and guesses. But, I hope the general scale and logic of these estimates still conveys the point, even if they aren’t accurate.)

Animals Killed in the Past

To get the number of animals that humans have killed in the past, let’s assume that the number of animals killed has grown at the same rate as the human population. This model, while not being completely accurate, will at least give us a reasonable estimate for animals killed in the past.

If we use this model and go back to the year 5000 BCE, then our model estimates that humans killed around 150 trillion animals in the past. Just for context: a million seconds is about 11 days; a billion seconds is about 31 years; and a trillion seconds is around 31,700 years, or nearly 32 millennia.

150 trillion animals killed is a completely astronomical number.

Animals Killed in the Future

Now, let’s look at how many animals might be killed by humans in the future.

Because the future hasn’t happened yet, there isn’t a “correct” answer to this question—there are only guesses that we can make based on different hypothetical scenarios. I’ll walk us through a few of those scenarios so that we can get a sense of what different versions of the future might look like.

Many of them, though, show that most of the animals who have existed or will exist could exist in the future, meaning they haven’t even been born yet. (Even though the number of animals already killed by humans over the course of history is so large.)

Scenario #1: Current Consumption, Eventual Societal Collapse

In this first scenario, we’ll use a very simple model of the future: Humanity stays the exact same as it is right now, and lasts another 1000 years before society completely collapses and humans go extinct.

Since humans currently kill somewhere around 1 trillion land animals and fish each year, this scenario implies that humans would kill (1 trillion animals per year) * (1000 years) = 1000 trillion (or 1 quadrillion) more animals in the future.

In this case, 87% of all animals who humans will ever kill live in the future. (1000/(1000+150))

Scenario #2: Cyclical Society Collapse and Rebuild

Humans are pretty scrappy and can learn to live almost anywhere on the planet. If global human society were to collapse in a significant way, I think there’s a good possibility that some communities would find a way to continue surviving.

So in this scenario, let’s assume that society collapses sometime this year and brings us back to the point of ancient civilizations, somewhere around 3000 BCE. Let’s also assume that this pattern of growth and collapse will occur again in exactly the same manner as before, and that it will occur some number of times…maybe five more times before humans go extinct.

In this case, we can take the total number of animals that humans have killed for food in the past (150 trillion) and assume that humans will kill this number again in each successive cycle. This means the total number of animals killed by humans for food in the future is (150 trillion per cycle) * (5 more cycles) = 750 trillion animals, which would mean that 83% of all animals killed by humans will live in the future.

Scenario #3: Long-Term Human Civilization

With the meteoric rise of industrialization and advanced technologies like computers, it’s not hard to imagine that humans might continue developing and growing into the far future, even to the point of colonizing other planets and star systems. (It’s also not hard to imagine us using that industrialization and technology to destroy society.)

Let’s assume that the human population continues existing into the future at the current population, and continues eating animals at the current rate. We know that the human population will actually continue growing (at least for some time), and the number of animals killed for food will also probably continue growing (at least for some time), but it simplifies the calculations to assume that things remain the same—and the conclusion is still just as profound.

Humans have to go extinct at some point, even if that point is billions of years in the future (unless it turns out we can find a way to decrease entropy in the universe), so we still need to estimate a length of time that humans will exist. Let’s try two different numbers: 10,000 years, and 10,000,000 years.

If humans survive another 10,000 years killing animals for food at our current rate, then 98.5% of all those animals will exist in the future, which is already the vast majority.

But if humans survive another 10,000,000 years, then 99.999% of the animals exist in the future.

Scenario #4: Vegan World Next Year

Just because this is the world we’re all going for, let’s assume that killing animals for food becomes illegal next year and stays illegal for the rest of the history of humanity, and that we have a big old happy vegan world.

Animals will still be killed this year, but after this year zero more animals will be killed by humans for food, which means 100% of animals killed for food would be in the past. In this scenario, we’re good! Mission accomplished.

Complications—Mission Accomplished?

There are at least two primary complicating factors here that we haven’t considered:

  1. We haven’t been considering well-being, only lives. I think we could all agree that it’s better for individuals to have happy, healthy lives than miserable, sick ones. It makes a big difference whether there are 100 trillion animals who all live mostly happy and healthy lives, or whether there are 100 trillion animals whose every moment is full of suffering and torment.
  2. Our scope has remained limited to just animals killed by humans for food, which doesn’t include the very large problem of wild animal suffering, and it also doesn’t include the problem of animals killed and controlled by humans for other reasons.

Both of these issues are very important, and they both add a layer of complexity to our thinking. For now though, we’re going to leave in-depth discussions of these topics for a later date. (For a crash course on the problem of wild animal suffering, see here, here, and here.)

The Future—Recap

As you can see from the models above, it doesn’t take much before the majority of the animals actually exist in the future—and in some scenarios, practically 100% of them do.

This all gets a little bit abstract when we’re talking about the future, so what does it actually mean?

It means that we need to figure out how to make our impact last into the future so that all of those trillions (and quadrillions) of animals aren’t born into this world just to suffer and be killed by humans. If we figure it out, then we can prevent a truly astronomical amount of suffering from ever happening.

The last thing we want is for humans to go on a universe-colonizing spree and bring their animal exploiting tendencies with them to countless other planets.

Practical Takeaways (…sort of)

All of this high-minded talk about the “far future” may be interesting, but what can animal advocates practically take away from this discussion? Is this topic too far off into the hypothetical to have any real, practical advice?

I think there are several actionable takeaways here already, although I would love to see more research done in this area.

Takeaway #1—Go by the Numbers

The first implication is that we need to really look at the numbers of animals harmed and killed by humans, and look at where those numbers might increase most in the future and what kinds of animals will be affected.

As a very practical example, it could be partially the case that the demonization of red meat over the last few decades has helped give rise to the enormous numbers of chickens killed and eaten every year. Similarly, fish are already the most killed animals for food globally, by far—if we ignore them in our advocacy, we might see yet another massive increase in the numbers of fish being born, killed, and eaten. Since chickens and fish receive much less empathy from humans than pigs and cows (and fish are much harder to relate to in nearly every way), this issue can fall off the radar. In fact, getting the animal advocacy movement to talk about the huge number of chickens took quite a few years, and we’re now in the process of slowly starting to advocate more specifically for fish.

Knowing the numbers matters.

Takeaway #2—Macro Trends

A second implication of focusing on the future is that we should become students of macro-societal trends and evolutions in order to understand (a) which big, lasting shifts occur in societies, and (b) how those shifts occurred.

We can look to other social movements to see how victories were achieved, like the civil rights movement or the marriage equality movement. We can study the rise of intensive animal farming, or the history of animal agriculture from the beginning of humanity until now. And we can also ask, “Which ideas have lasted the longest?”, and then deconstruct which practices or features of those ideas helped them to survive. For example, we could look to ideas from old religions and civilizations that have lasted through long stretches of time and influenced modern society, and hypothesize what made them different from other ideas that didn’t have as much of an influence.

A great example of analyzing macro trends is the book The Better Angels of Our Nature by Steven Pinker, which looks at the global decline in violence over the course of human history. Similar studies can be found (or conducted) for other phenomena as well.

Takeaway #3—Global Focus

One very specific macro trend is the importance of looking globally.

I live in the United States, which directly accounts for about 2% of all animals killed for food by humans each year. China, on the other hand, accounts for about 50% of all animals killed for food each year. India accounts for another 10%, and Indonesia for yet another 8%. (source)

Let’s say we completely end animal farming in the United States. While this would be a great accomplishment by itself, it would only spare 2% of the animals killed for food. To have a significant impact, that accomplishment would need to influence countries like China, India, and Indonesia.

We have to keep our focus global. With two-thirds of all the world’s farmed animals living in China, India, and Indonesia, we have to remember that success for farmed animals in the US or UK or Australia doesn’t necessarily translate to global success.

Takeaway #4—Resilience to Societal Disruption

Human societies change—constantly.

Just for a little perspective…

  • Christianity came into existence about 1900 years ago.
  • The (Western) Roman Empire stopped existing around 1500 years ago.
  • Islam came into existence around 1400 years ago.
  • The American Revolution was 236 years ago.
  • The French Revolution was 220 years ago.
  • Slavery was abolished in the British Empire 186 years ago.
  • WWI was 101 years ago, and WWII was 74 years ago.
  • The first radio news program was broadcast 99 years ago.
  • The internet went public about 30 years ago.
  • The Soviet Union stopped existing 28 years ago.
  • 9/11 was 18 years ago.
  • The first iPhone came out 12 years ago.
  • Instagram came out 9 years ago.
  • The AI system Watson defeated the two reigning Jeopardy! champions 8 years ago.
  • A self-driving semi truck drove on public roads without a human inside for the first time 1 year ago.

Just a gentle reminder that we have very little idea what the future is going to look like. And because of this, we need our progress for animals to be global, and to be resilient to massive societal disruptions and overhauls and shifts in power.

What happens if we achieve total animal liberation in the United States, and then China goes on to become the major world power and ethical influence? What if there’s another global war? What if a quasi-apocalypse happens and much of human society is destroyed? How does the rise of artificial intelligence affect our ethical progress? How might our morals change when we send humans to other planets?

Our ethical progress must be able to survive these disruptions if we want to prevent the huge amount of suffering and death that could happen if animal exploitation continued existing into the far future.

Takeaway #5—Focus on Structural Changes

How does something last from one generation of humans to the next? Or from one millennia to the next?

It lasts because of something that carries it forward into the future. That “something” is often a structural entity of some sort: a religion, a culture, a government, a corporation, a university, a law.

If you change someone’s mind about something, and that person changes their behavior, and then that person dies (as we all do eventually), how do the changes they made continue into the future? They only last if they impact someone else who is still alive. This is why we can’t just rely on changing the attitudes and behavior of individual people—because we then depend on those people to propagate that change into the future on their own.

Maybe they will, maybe they won’t.

Influencing structures, on the other hand, increases the probability of the change being carried forward.

Takeaway #6—Focus on Moral Circle Expansion, Aided by Technological Progress

We can’t trick people into doing the right thing for the wrong reason, because at some point the wrong reason won’t be applicable and people will change again.

For example, as powerful and as useful as health and environmental arguments are for veganism (and they are useful!), we must at some point bring in the full weight of the ethical argument if we are to make lasting progress for animals.

This ethical progress is the process of expanding humanity’s moral circle.

Second, technological progress can greatly aid this process. As Malala Yousafzai‘s father discovered, people are much more open to girls’ education when they have clean water.” It’s hard to care about higher ethics when you feel like you’re having a hard time meeting basic needs—and to some people, completely switching their way of eating can feel like a need isn’t being met. Technology is another name for “creative use of resources to meet needs”. We should use it.


I hope this article has at least prompted some thought about the importance of making our impact last into the far future. This is a big topic—and very complex and uncertain—so we need all of us to be thinking about it in relation to our activism.

For more discussion of the moral value of beings in the far future, check out:

And maybe with all of us working on it, we’ll get this problem solved in the not-too-far-future.

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