The atmospheric changes I had in mind were the expansion of human population and burning of wood. I wrote about cultural factors in a sibling comment.

I am not expert in these areas, but the main reason my comment was so brief was that I was working on something else at the time and glanced at HN while waiting for computations to render.

I share the doubts with the OP.

Your comments are ad hominem. It doesn't matter whether OP has the "necessary knowledge" (read: pedigree and institutional background) to bring up clear confounders.

The mere naming of them is sufficient to make the link. The names of colors have evolved -- no word for Orange for a long time! Perhaps "Yellow" was used instead.

Further, without public access, there is no great way for the OP to respond directly.

Thus, the onus is on the paper's distribution. But you don't call that out. Why?

It is freely available on ArXiv.

https://arxiv.org/abs/2207.04702

Can you confirm this is the post-publication print, not a pre-publication? Not that the content is changed substantially -- but it could have.

Well, the paper was released on July 29th, and the last revision (v2) of the ArXiv document was July 27th, so without going through the whole thing twice I would strongly suspect they are the same.