I was referring to either this one: https://www.nber.org/papers/w26167 or some other with similar scale of estimates, using what I presume to be mainstream predictions of temperature growth.

Edit: Also, you can easily tell without looking that the idea billions would have to relocate is a complete joke. The reason is, let’s suppose global warming makes a region unfarmable. Well, even if it were farmable, automation in the 3rd world will move people out of farming anyway. So they’d have to be doing other work, trading for food, no matter what happens.