I.

I’ve previously argued that meat-eaters concerned about animal welfare should try to eat beef, not chicken. The logic goes: the average cow is very big and makes 405,000 calories of beef. The average chicken is very small and makes 3000 calories of chicken. If you eat the US average of 250,000 calories of meat per year, you can either eat 0.5 cows, or 80 chickens. If each animal raised for meat experiences some suffering, eating chicken exposes 160x more animals to that suffering than eating beef.

Might cows be “more conscious” in a way that makes their suffering matter more than chickens? Hard to tell. But if we expect this to scale with neuron number, we find cows have 6x as many cortical neurons as chickens, and most people think of them as about 10x more morally valuable. If we massively round up and think of a cow as morally equivalent to 20 chickens, switching from an all-chicken diet to an all-beef diet saves 60 chicken-equivalents per year.

But some people have argued that we also need to consider global warming. Cows produce methane, which is a powerful greenhouse gas. Chickens don’t. How does this affect the calculations?

According to Eshal et al 2014, chickens produce about 2 kg CO2 equivalent per 1000 calories of meat, and cows about 10 kg (here “CO2 equivalent” means a collection of greenhouse gases, especially methane, that produce as much global warming as that many kg CO2). Going back to the average person who eats 250,000 calories of meat per year, the person who eats all beef is producing 2500 kg CO2 per year; the person who eats all chicken is producing 500 kg.

How much does this change things? The average US citizen produces 17.5 tons of CO2 per year. Suppose this average person was originally eating half beef and half chicken, in which case they would get 1250 kg CO2 from beef + 250 kg from chicken = 1.4 tons from beef + 0.3 tons from chicken. That leaves 15.8 tons coming from other things like cars and plane flights.

So if this average person switched to eating only chicken, their yearly CO2 production would drop from 17.5 tons to 16.4 tons. If they switched to eating only beef, their yearly CO2 production would rise from 17.5 tons to 18.6 tons. So the CO2 difference between an all-beef and an all-chicken diet is 16.4 tons of CO2 yearly vs. 18.6 tons yearly, or about 10%.

So switching from all-chicken to all-beef saves about 60 chickens per year, at the cost of 2.2 tons extra CO2, a 10% increase in your yearly production.

Nobody agrees on exactly how much it costs to offset a ton of carbon. This site says “anywhere from $0.10 per tonne to $44.80 per tonne”, but eventualy settles on $3.30. QZ says “between $4 and 13 per metric ton”. Terrapass sells offsets for $10 a ton; let’s stick with that for now, while admitting it’s at best an order-of-magnitude estimate.

Offsetting the carbon cost of going from an all-chicken diet to an all-beef diet would cost $22 per year, or about 5 cents per beef-based meal. Since you would be saving 60 chickens, this is three chickens saved per dollar, or one chicken per thirty cents. A factory farmed chicken lives about thirty days, usually in extreme suffering. So if you value preventing one day of suffering by one chicken at one cent, this is a good deal.

II.

This is the simple version of this argument for public consumption. Everything below is optional and makes things much worse and more complicated without an obvious change in the conclusion.

It’s unfair to compare direct action on animal suffering (in the form of eating beef rather than chicken) to offsets on global warming. What if we were to make the opposite comparison - direct action on global warming vs. offsets on animal suffering? IE you eat chicken because it’s better for the planet than beef, then offset the costs with donations to effective animal charities.

How much does it cost to offset animal suffering by saving more animals from more suffering? Many charities have made claims about this, some more hyperbolic than others. I am not an expert in animal charity evaluation, and the people who are refuse to give numbers for this because they know that dumb people like me would interpret their wild guesses as gospel truth. But some good effective altruist organizations did some research that loosely suggests a cost of $6 to save one chicken.

So if you wanted to go from an all-beef diet to an all-chicken diet to prevent global warming, you could offset the 60 extra chickens by paying $360.

So imagine our standard American, eating half beef and half chicken. He might offset the cost of the chicken he eats with $180 to effective animal suffering charities, and offset the cost of the beef that he eats with $11 to effective carbon offset charities. If he wanted to switch to all-beef, he would owe an extra $11; all-chicken, an extra $180.

If you are actually doing the offsets, you should eat whatever you find most delicious, since it’s morally neutral anyway. But what if you’re not going to? Should you eat more beef, on the grounds that the market has priced its moral cost at lower than chicken’s moral cost?

Imagine a world where Yog Sothoth was constantly devouring galaxies full of intelligent life forms, an atrocity beyond your ability to imagine. But there was a charity that could stop him at a cost of $1 per galaxy. But in practice, not very many people donated to this charity - or maybe lots of people donated to it, but Yog Sothoth is vast and devours far more galaxies than mere mortals have dollars, so many galaxies are getting devoured despite this very effective prevention strategy.

And imagine that every time you ate chicken for dinner, Yog Sothoth would devour an extra galaxy. We calculate it out and find that eating chicken only causes the equivalent of $1 in damage (since Yog Sothoth eats only one extra galaxy, and we can save one galaxy for a dollar). The implied moral is “Go ahead and eat chicken, it only does $1 worth of damage and that’s not much”. But actually, it causes an entire galaxy full of intelligent beings to die.

Now imagine that beef still causes global warming, and that you can offset the global warming caused by one beef dinner at $2 (real world prices are lower, but grant it for the sake of argument).

Someone thinks “I could eat chicken and offset it with $1, or I could eat beef and offset it with $2, I’m not actually going to do the offsetting, but the market has said chicken is less morally costly than beef”. Then that person eats chicken and destroys a galaxy, when they could have eaten beef and produced a few extra pounds of carbon.

The moral of the story is: if there’s some kind of weird market failure that causes galaxies to be priced at $1, normal reasoning stops working; things that do incalculable damage can be fairly described as “only doing $1 worth of damage”, and you will do them even if less damaging options are available.

(it’s still totally fair to eat chicken and donate $1 to the Stop Yog Sothoth Fund, it’s just catastrophic if you abstract away the step where you donate the dollar)

Either carbon offsets, animal suffering offsets, or both could be market failures like this. In fact, if you believe that we’re currently not doing enough to fight climate change or animal suffering, I think you almost have to believe there are market failures in offsets.

So all statements like “eating beef only causes 30 cents worth of damage” and “eating beef is cheaper to offset than eating chicken” have to be adjusted based on how bad a failure there is for beef and chicken offsets. Since we don’t know these numbers, we should be wary of thinking the prices of either offset tell us very much.

But I would argue the balance is still in favor of eating beef over chicken. First, the offset cost of $10 per ton of carbon is pretty well-studied and probably order-of-magnitude right. The $6 per chicken cost is almost completely made up. While some would say this gives it an advantage (because it could be much better than this) I think the usual rule is that the more made-up a number is, the more likely it is to be skewed in favor of looking good. This should bias us against a strategy that relies on chicken offsets.

Second, most likely anything you personally do to prevent global warming won’t matter at all; either very large-scale actors like states and corporations will fail and there will be various disasters, or the large-scale actors will succeed and we will escape most problems. Meanwhile, if you don’t eat some chickens, those particular chickens don’t get eaten. While I don’t like thinking in these terms too much because it prohibits superrational coordination, I think it’s fair to take them into account as a tiebreaker.

In conclusion, eating beef causes more climate change than eating chicken, but eating chicken causes more animal suffering than eating beef. Offsetting the climate change effects of beef would only cost $22 per year, which seems really good. Offsetting the animal suffering effects of chicken might only cost $360 per year, but this is a very tentative estimate and maybe shouldn’t be taken seriously. Also, these only work if you’re actually doing the offsetting. If not, you should probably default to eating beef over chicken, but I can’t prove it.