Reducing existential risks or wild animal suffering?

This article argues why reducing wild animal suffering may be more important than reducing existential risks. The argument is largely based on my newly developped population ethical theory of variable critical level utilitarianism.

What are the most important focus areas if you want to do the most good in the world? Focus on the current generation or the far future? Focus on human welfare or animal welfare? These are the fundamental cause prioritization questions of effective altruism. Look for the biggest problems that are the most neglected and are the easiest to solve. If we do this exercise, two focus areas become immensely important: reducing existential risks and reducing wild animal suffering. But which of those two deserves our top priority?


An existential risk (X-risk) is a catastrophic disaster from nature (e.g. an asteroid impact, a supervirus pandemic or a supervolcano eruption), technologies (e.g. artificial superintelligence, synthetic biology, nanotechnology or nuclear weapons) or human activities (e.g. runaway global warming or environmental degradation), that can end all of civilization or intelligent life on earth.

If we manage to avoid existential risks, there can be flourishing human or intelligent life for many generations in the future, able to colonize other planets and multiply by the billions. The number of sentient beings with long happy flourishing lives in the far future can be immense: a hundred thousand billion billion billion (1032) humans, including a million billion (1016) humans on Earth, according to some estimates. In a world where an existential risk occurs, all those potentially happy people will never be born.


Wild animal suffering (WAS) is the problem created by starvation, predation, competition, injuries, diseases and parasites that we see in nature. There are a lot of wild animals alive today: e.g. 1013 – 1015 fish, 1017 – 1019 insects, according to some estimates. It is possible that many of those animals have lives not worth living, that those animals have more or stronger negative than positive experiences and hence overall a negative well-being. Most animals follow an r-selection reproductive strategy: they have a lot of offspring (the population has a high rate of reproduction, hence the name ‘r-selection’), and only a few of them survive long enough to reproduce themselves. Most lives of those animals are very short and therefore probably miserable. We are not likely to see most of those animals, because they will die and be eaten quickly. When we see a happy bird singing, ten of its siblings died within a few days after hatching. When the vast majority of newborns die, we can say that nature is a failed state, not able to take care of the well-being of its inhabitants.

Due to the numbers (billions of billions), the suffering of wild animals may be a bigger problem than all human suffering from violence, accidents and diseases (a few billion humans per year), and all human caused suffering of domesticated animals (a few hundred billion per year).

Population ethics

What is worse: all the suffering, today and in the future, of wild animals who have miserable lives? Or the non-existence of a huge number of people in the far future who could have had beautiful lives? To solve this question, we need to answer one of the most fundamental question in ethics: what is the best population ethical theory? Population ethics is the branch of moral philosophy that deals with choices that influence who will exist and how many individuals will exist.

A promising population ethical theory is the variable critical level utilitarianism. Each sentient being has a utility function that measures how strongly that individual prefers a situation. That utility can be a function of happiness and all other things valued by that individual. If your utility is positive in a certain situation, you have a positive preference for that situation. The more you prefer a situation, the higher your utility in that situation. If a person does not exist, that person has a zero utility level.

The simplest population ethical theory is total utilitarianism, which says that we should choose the situation that has the highest total sum of everyone’s utilities. However, this theory has a very counter-intuitive implication, called a sadistic repugnant conclusion (a combination of the sadistic conclusion and the repugnant conclusion in population ethics). Suppose you can choose between two situations. In the first situation, a million people exist and have maximally happy lives, with maximum utilities. In the second situation, those million people have very miserable lives, with extremely negative levels of utility. But in that situation, there also exist new people with utilities slightly above zero, i.e. lives barely worth living. If we take the sum of everyone’s utilities in that second situation, and if the number of those extra people is high enough, the total sum becomes bigger than the total of utilities in the first situation. According to total utilitarianism, the second situation is better, even if the already existing people have maximally miserable lives and the new people have lives barely worth living, whereas in the first situation everyone is maximally satisfied, and no-one is miserable.

To avoid this conclusion, we can change the utilitarian theory, for example by using a reference utility level as a critical level. Instead of adding utilities, we add relative utilities, where a relative utility of a person is his or her utility minus the critical level. The critical level of a non-existing person is zero. This population ethical theory is the critical level utilitarianism, and it can avoid the sadistic repugnant conclusion: if the critical level is higher than the small positive utilities of the new people in the second situation, the relative utilities of those extra people are all negative. The sum of all those relative utilities never becomes positive, which means the total relative utility of the first situation is always higher than the second situation, and so the first situation is preferred.

If all critical levels of all persons in all situations are the same, we have a constant or rigid critical level utilitarianism, but this theory still faces some problems. We can make the theory more flexible by allowing variable critical levels: not only can everyone determine his or her own utility in a specific situation, everyone can also choose his or her critical level. The preferred critical level can vary from person to person and from situation to situation.

A person’s critical level always lies within a range, between his or her lowest preferred and highest preferred levels. The lowest preferred critical level is zero: if a person would choose a negative critical level, that person would accept a situation where he or she can have a negative utility, such as a life not worth living. Accepting a situation that one would not prefer, is basically a contradiction. The highest preferred critical level varies from person to person. Suppose we can decide to bring more people into existence. If they choose a very high critical level, their utilities fall below this critical level, and hence their relative utilities become negative. In other words: it is better that they do not exist. So if everyone would choose a very high critical level, it is better that no-one exists, even if people can have positive utilities (but negative relative utilities). This theory is a kind of naive negative utilitarianism, because everyone’s relative utility becomes a negative number and we have to choose the situation that maximizes the total of those relative utilities. It is a naive version of negative utilitarianism, because the maximum will be at the situation where no-one exists (i.e. where all relative utilities are zero instead of negative). If people do not want that situation, they have chosen a critical level that is too high. If everyone chose their highest preferred critical level, we end up with a better kind of negative utilitarianism, which avoids the conclusion that non-existence is always best. It is a quasi-negative utilitarianism, because the relative utilities are no-longer always negative. They can sometimes be (slightly) positive, in order to allow the existence of extra persons.

X-risks versus WAS

Now we come to the crucial question: if variable critical level utilitarianism is the best population ethical theory, what does it say about our two problems of existential risks and wild animal suffering?

If everyone chose their lowest preferred critical level, we end up with total utilitarianism, and according to that theory, the potential existence of many happy people in the far future becomes dominant. Even if the probability of an existential risk is very small (say one in a million the next century), reducing that probability is of highest importance if so many future lives are at stake. However, we have seen that total utilitarianism contains a sadistic repugnant conclusion that will not be accepted by many people. This means those people decrease their credence in this theory.

If people want to move safely away from the sadistic repugnant conclusion and other problems of rigid critical level utilitarianism, they should choose a critical level infinitesimally close to (but still below) their highest preferred levels. If everyone does so, we end up with a quasi-negative utilitarianism. According to this theory, adding new people (or guaranteeing the existence of future people by eliminating existential risks) becomes only marginally important. The prime focus of this theory is avoiding the existence of people with negative levels of utility: adding people with positive utilities becomes barely important because their relative utilities are small. But adding people with negative utilities is always bad, because the critical levels of those people are always positive and hence their relative utilities are always negative and often big in size.

However, we should not avoid the existence of people with negative utilities at all costs. Simply decreasing the number of future people (avoiding their existence), in order to decrease the number of potential people with miserable lives, is not a valid solution according to quasi-negative utilitarianism. Suppose there will be one sentient being in the future who will have a negative utility, i.e. a life not worth living, and the only alternative option to avoid that negative utility, is that no-one in the future exists. However, the other potential future people strongly prefer their own existence: they all have very positive utilities. In order to allow for their existence, they could lower their critical levels such that a future with all those happy future beings and the one miserable individual is still preferred. This means that according to quasi-negative utilitarianism, the potential existence of one miserable person in the future does not imply that we should prefer a world where no-one will live in the future. However, what if a lot of future individuals (say a majority) have lives not worth living? The few happy potential people will have to decrease their own critical levels below zero in order to allow their existence. In other words: if the number of future miserable lives is too high, a future without any sentient being would be preferred according to quasi-negative utilitarianism.

If everyone chooses a high critical level such that we end up with a quasi-negative utilitarianism, we should give more priority to eliminating wild animal suffering than eliminating existential risks, because lives with negative utilities are probably most common in wild animals and adding lives with positive well-being is only minimally important. In an extreme case where most future lives would be unavoidably very miserable (i.e. if the only way to avoid this misery is to avoid the existence of those future people), avoiding an existential risk could even be bad, because it would guarantee the continued existence of this huge misery. Estimating the distribution of utilities in future human and animal generations becomes crucial. But even if with current technologies most future lives would be miserable, it can still be possible to avoid that future misery by using new technologies. Hence, developing new methods to avoid wild animal suffering becomes a priority.

Expected value calculations

If total utilitarianism is true (i.e. if everyone chooses a critical level equal to zero), and if existential risks are eliminated, the resulting increase in total relative utility (of all current and far-future people) is very big, because the number of future people is so large. If quasi-negative utilitarianism is true (i.e. if everyone chooses their maximum preferred critical level), and if wild animal suffering is eliminated, the resulting increase in total relative utility of all current and near-future[1] wild animals is big, but perhaps smaller than the increase in total relative utility by eliminating existential risks according to total utilitarianism, because the number of current and near-future wild animals is smaller than the number of potential far-future people with happy lives. This implies that eliminating existential risks is more valuable, given the truth of total utilitarianism, than eliminating wild animal suffering, given the truth of quasi-negative utilitarianism.

However, total utilitarianism seems a less plausible population ethical theory than quasi-negative utilitarianism because it faces the sadistic repugnant conclusion. This implausibility of total utilitarianism means it is less likely that everyone chooses a critical level of zero. Eliminating existential risks was most valuable when total utilitarianism was true, but its expected value becomes lower because the low probability of total utilitarianism being true. The expected value of eliminating wild animal suffering could become higher than the expected value of eliminating existential risks.

But still, even if the fraction of future people who choose zero critical levels is very low, the huge number of future people indicate that guaranteeing their existence (i.e. eliminating existential risks) remains very important.

The interconnectedness of X-risks and WAS

There is another reason why reducing wild animal suffering might gain importance over reducing existential risks. If we reduce existential risks, more future generations of wild animals will be born. This increases the likelihood that more animals with negative utilities will be born. For example: colonizing other planets could be a strategy to reduce existential risks (e.g. blowing up planet Earth would not kill all humans if we could survive on other planets). But colonization of planets could mean introducing ecosystems and hence introducing wild animals, which increases the number of wild animals and increases the risk of more future wild animal suffering. If decreasing existential risks means that the number of future wild animals increases, and if this number becomes bigger and bigger, the non-existence of animals with negative utilities (i.e. the elimination of wild animal suffering) becomes more and more important.

On the other hand, if an existential risk kills all humans, but the non-human animals survive, and if humans could have been the only hope for wild animals in the far future by inventing new technologies that eliminate wild animal suffering, an existential risk might make it worse for the animals in the far future. That means eliminating existential risks might become more important when eliminating wild animal suffering becomes more important.

So we have to make a distinction between existential risks that could kill all humans and animals, versus existential risks that would kill only those persons who could potentially help future wild animals. The second kind of existential risk is bad for wild animal suffering, so eliminating this second kind of risk is important to eliminate wild animal suffering in the far future.


The difference between total utilitarianism (prioritizing the elimination of existential risks) and quasi-negative utilitarianism (prioritizing the elimination of wild animal suffering), can also be understood in terms of victimhood. If due to an existential risk a potential happy person would not exist in the future, that non-existing person cannot be considered as a victim. That non-existing person cannot complain against his or her non-existence. He or she does not have any experiences and hence is not aware of being a victim. He or she does not have any preferences in this state of non-existence. On the other hand, if a wild animal has a negative utility (i.e. a miserable life), that animal can be considered as a victim.

Of course, existential risks create victims: the final generation of existing people would be harmed and would not like the extinction. But this number of people in the last generation will be relatively small compared to the many generations of many wild animals who can suffer. So if the status of victimhood is especially bad, wild animal suffering gets worse than existential risks, because the problem of wild animal suffering creates more victims.


Both existential risk reduction and wild animal suffering reduction are important focus areas of effective altruism, but reducing wild animal suffering seems to be more neglected. Only a few organizations work on reducing wild animal suffering: Wild-Animal Suffering Research, Animal Ethics, Utility Farm and the Foundational Research Institute. On the other hand, there are many organizations working on existential risks both generally (e.g. the Centre for the Study of Existential Risk, the Future of Humanity Institute, the Future of Life Institute, the Global Catastrophic Risk Institute and 80000 Hours) and specifically (working on AI-safety, nuclear weapons, global warming, global pandemics,…). As wild animal suffering is more neglected, it has a lot of room for more funding. Based on the importance-tractability-neglectedness framework, wild animal suffering deserves a higher priority.


In the population ethical theory of variable critical level utilitarianism, there are two extreme critical levels that correspond with two dominant population ethical theories. If everyone chooses the lowest preferred critical level (equal to zero), we end up with total utilitarianism. If everyone chooses the highest preferred critical level, we end up with quasi-negative utilitarianism. According to total utilitarianism, we should give top priority to avoiding existential risks such that the existence of many future happy people is guaranteed. According to quasi-negative utilitarianism, we should give top priority to avoiding wild animal suffering such that the non-existence of animals with miserable lives (negative utilities) is guaranteed (but not always simply by decreasing or eliminating wild animal populations and not necessarily at the cost of whipping out all life).

The value of eliminating existential risks when everyone chooses the lowest preferred critical level would probably be higher than the value of eliminating wild animal suffering when everyone chooses the highest preferred critical level. But total utilitarianism is less likely to be our preferred population ethical theory because it faces the sadistic repugnant conclusion. This means that the expected value of eliminating wild animal suffering could be bigger than the expected value of eliminating existential risks. These calculations become even more complex when we consider the interconnectedness of the problems of existential risks and wild animal suffering. For example, decreasing existential risks might increase the probability of the existence of more future wild animals with negative utilities. But eliminating some existential risks might also guarantee the existence of people who could help wild animals and potentially eliminate all future wild animal suffering with new technologies.

Finally, wild animal suffering deserves a higher priority because this focus area is more neglected than existential risks.

[1] We cannot simply add the relative utilities of far-future wild animals, because that would presume that existential risks are avoided.