Interesting idea. Just one comment about Adani. I don't know much about his potentially positive impact in India or elsewhere, but I do know about his connection to coal (in particular in Australia), which I would bet has overall a significantly negative impact. It's unclear to me if anyone else would have counterfactually made a similarly huge investment in Australian coal industry at this point.

Whether and to what extent the survivors could catch up with the counterfactual universe strongly depends on the boundary conditions. Universe A could have expanded to other planets by the time B fully recovers. We are comparing the potential of a full, and fully developed humanity with a small post-apocalyptic fraction of humanity. I agree with you that planet boundaries (and other physical constraints) could reduce the potential of a random 1% in A with respect to B. But I suppose it can also go the other way: The survivors in B could produce less humans than any 1% of A, and keep this trend for many (even all) future generations. My intuition here is very limited.

The survivors in B would eventually catch up with the living population of the world today, yes. However, the survivors in B would never catch up with the cumulative population of the universe where there was no catastrophe. While the survivors in B were recovering, the counterfactual universe has been creating more humans (as well as new pieces of art, scientific discoveries, etc.). It is impossible for B to catch up, regardless of how much you wait. All the human potential of the 99% who died in the catastrophe is lost forever.

Hi Phil. I'm also not an authority on the topic, but I think your summary of longtermism is not accurate. You seem to be worried about the effects of the knowledge explosion, which means that you also care about the future. Maybe you disagree with strong longtermism (as I do, for the reasons above) or think that we should worry about the not-so-distant future. I would say that is still to some extent (a fraction of) longtermism. So even if you don't buy the whole package, you may still agree with a part of longtermism.

The number of humans who will ever live is similar in scenarios A and B. But keep in mind that in scenario A we have randomly picked only 1% of all existing humans. The catastrophe that takes place in scenario B removes 99% of all humans alive, which in turn removes around 99% of all humans that could have lived at the end of time. That is an enormous difference in the long term. And that is the main point of that section: Saving lives now has an enormous impact in the long term.

Hi Stephen. I think I should have made this part clearer (I guess a chart would help). Consider the following scenarios:

A)  In Universe A nothing catastrophic happens today. You can pick any 1% of the world and trace the cumulative number of humans they produce between today and the end of time.

B)  In Universe B, a catastrophe happens today, leaving only 1% alive. You can trace the cumulative number of humans they produce between today and the end of time.

My intuition is that the cumulative number of humans that will ever exist at the end of time is similar in A and B. This applies to any random 1% of humans from Universe A. With this in mind, losing 99% of humanity today is approximately 99% worse than losing any 1% (including the last).

This article seems to have good SEO for keywords involving "effective altruism" and "veganism", which I find unfortunate. I appreciate the author's effort to quantify such a complex topic, and I think it's a very important conversation to have. There are already very good arguments against the article's conclusions in the comments, purely based on ethical grounds. But I'll add an important argument that seems to be missing in the conversation: the author's conclusions are short-termist.

The author's main point is that there is a cost in the transition to veganism, and that cost should be better spent on saving human lives now. My counter-argument is: transitioning to veganism now saves more human lives in the long term (as well as animal lives, of course).

The cost of animal products neglects their massive environmental and health impact. If animal products reflected their true cost, becoming vegan would actually save money, that could therefore be spent in donations to charity. Unfortunately, we don't live in a world where the cost of goods and services reflects their positive or negative impact. Yet, precisely, by transitioning to a vegan life (or as vegan as possible), we are collectively shifting the market in that direction.

The author could apply a similar argument against transitioning to green energy: Instead of investing in clean energy today, humankind could spare that money and sacrifice, and spend it on saving human lives. But clearly, in the long term, we save more lives by moving to clean energy now than in the future, when it may be too late.

I know that the author wanted to talk solely about the ethical aspects of veganism, and not necessarily the health and environmental ones. But, given that his conclusions are economical, it is naive to neglect those other aspects in the conversation. Deciding to go vegan today (and helping spread the message) may have an individual cost today, but it has a positive long-term impact that justifies that initial cost.

Finally, I also wanted to add that, for some people, becoming vegan may not be affordable. But those people in economic hardship will not donate significantly to charities anyway. Instead, for a large (and increasing) population, a vegan life is perfectly affordable, and also enjoyable. That is my case, living in a modern European city, and I know that it's also the case in many other cities in the US, UK, Australia, and elsewhere. So becoming vegan is neither more expensive, nor a big personal sacrifice.