Introduction

In this post, I argue that the scale of farmed animal suffering far exceeds the expected mortality risk from engineered pandemics—by a factor of at least 100. I haven’t seen this explicit comparison made elsewhere, yet it strongly affects my personal cause prioritization.

However, it’s important not to update solely on scale: the tractability and neglectedness of pandemic preparedness may still justify prioritizing it, despite its seemingly smaller scale. I would be excited to see more detailed work in this area—for example, comparing the Disability-Adjusted Life Years (DALYs) lost to farming versus pandemics more rigorously than I do here.

Scale of biorisk

In The Precipice (2020), Toby Ord estimates a 1/30 risk of human extinction from engineered pandemics^[1] this century. Spreading this risk over 80 years—from 2020 to 2100—gives an approximate 1/2,360 chance of extinction per year (on average).

The average global population in the 21st century may be around 9 billion people. Multiplying this by the annual extinction probability implies an expected human death toll of roughly 3.8 million per year (i.e., 9 billion × 1/2,360).

Of course, DALYs lost to pandemics would be higher than just deaths, since pandemic survivors can suffer severe morbidity and long-term health consequences. Further, this calculation is a simplification in that it treats the extinction risk as evenly distributed each year, which is not necessarily accurate. The true distribution of risks might be heavily skewed toward certain time periods. ^[1]

Scale of industrial farming

Number of Animals

According to Our World in Data, 83 billion land animals and 128 billion farmed fish were slaughtered globally in 2022 for meat alone. While this number has been rising, I will assume for simplicity that it remains constant for the rest of the century (on average). 

Converting to human-equivalents

Rethink Priorities (RP) estimates that all land animals we farm have a welfare range bigger than 0.1, and all fish higher than 0.01. Using these figures, we might approximate each land animal as 0.1 of a “human-equivalent” in terms of potential suffering, and each fish as 0.01 of a human-equivalent. Multiplying:

• 83 billion land animals × 0.1 = 8.3 billion human-equivalents
• 128 billion fish × 0.01 = 1.28 billion human-equivalents

Summing these gives ~9.58 billion human-equivalents in suffering per year as a lower bound, compared to RP's numbers. Note that this calculation assumes that the “badness”/disutility of an animal dying is proportional to its welfare range - a stance that RP doesn't explicitly endorse. Here, I simply use the welfare range values as a rought proxy.

Caveats and Uncertainties

• These welfare range estimates are inherently subjective and vary between researchers. My personal guess is somewhat lower than RP’s, but not by more than an order of magnitude. If your range estimates differ by more, we might get different conclusions.
• The duration of suffering versus the duration of a human life is not directly accounted for here.
• DALYs lost likely exceed these simple “human-equivalent” calculations, since many animals endure intensely negative conditions for most or all of their lives.
• RP’s weights aren’t meant to compare lives in this fashion. Here, I use them more as a proxy than anything, which is part of why I round down significantly. 

Why I might be wrong

Apples to Oranges

The figure from Toby Ord focuses on extinction-level pandemics. Large, non-extinction pandemics could happen more frequently, increasing expected annual human deaths beyond the 3.8 million estimate without increasing extinction risk. If such mid-level pandemics become common, total pandemic-related mortality might be much larger than implied here.

Population Ethics

Under a totalist view , a catastrophic pandemic that kills a fraction of humanity (without total extinction) might still massively reduce our long-term population, shrinking the number of future lives. The classic case for existential risk work often looks beyond literal extinction to consider any permanent curtailment of civilization’s potential. 

I personally subscribe more to a person-affecting view, which means I place less weight on future people not getting the chance to exist compared to people already existing being negatively affected. If you're not a longtermist, this point will also be less relevant. 

Civilizational Collapse and Value Lock-In

A sufficiently severe pandemic might cause societal collapse, after which a new civilization can emerge with entrenched institutions that “lock in” certain values or systems. This lock-in could manifest as:

• An authoritarian system that oppresses humans.
• A continuation or scaling up of current factory-farming practices, resulting in the same or even greater animal suffering.

(Credit to Isaac Dunn for this idea.)

Animal Suffering from Pandemics

During the last pandemic, Denmark had to put down roughly 17 million minks over concerns of viral mutations. For bigger pandemics, we can expect similar or even more extreme measures affecting animals—especially if civilizational collapse occurs and less regulated “emergency” actions become commonplace. This possibility suggests that impacts on non-human animals from pandemics could be significant enough to warrant more biorisk research than the above comparison alone might indicate. 

(Credit to Sam Smith for this idea.)

1. ^{^}

   At the extreme, the risk could be 0 every year except for one year when it is 1/30. This would give an expected death toll of 333 million that year, which is equivalent to 4.17 million per year - only slightly bigger.