Where exactly is the line drawn for how much and what type of human intervention is required? When I cook food, human intervention is causing chemical reactions that change the composition of the food. I doubt many people consider grill marks to be unnatural or synthetic.

I think the line is typically drawn at any human intervention. I doubt many humans consider steaks to be a naturally occurring phenomenon.

Now, there is a secondary fuzzy notion of "artificial" typically used in relation to "chemicals". I don't think that definition stands up to most serious scrutiny, and is at any rate unrelated to this article.

That's exactly what's being—albeit atypically—advocated for here: That even steaks are a naturally occurring byproduct of humans and cows because humans and cows naturally exist.

Sure, but then of course absolutely everything is "naturally occurring". Plastic is a naturally occurring substance, computers are naturally occurring objects, C++ is a natural language. Perhaps then only miracles from God (for those who believe in such things) are unnatural?

In your example, I’d opt for supernatural over unnatural, and I get your meaning.

Now you're getting it.

I am, but this is just not what those words mean, to anyone.

Plenty of people do not believe the conceptualization of a natural/synthetic divide does any good. There are entire subsets of philosophy, feminism, cyborg theory, etc. which talk about this.

It may be heterodox, but it’s what it means to me, and I’m sure I’m not completely alone in feeling so.

In which case coral reefs are also synthetic :)

Most coral reefs predate human intervention by a few hundred million years.