https://astralcodexten.substack.com/p/carbon-costs-quantified

This post tries to quantify how much carbon is produced by various activities, lifestyle changes, and actors.

can't stress enough how approximate and unreliable these numbers are. The reason I made this chart and other people didn't isn't because I'm smarter or harder-working than they are. It's because I'm less responsible, and more willing to use numbers that are kind of grounded in wild guesses, and technically shouldn't be compared to each other. My defense is they're probably mostly order-of-magnitude correct, and I believe having probably mostly order-of-magnitude correct estimates is better than having no estimates at all.

Explanations below: