[gruez]

>Unless you're doing deep carbon extraction, nature is pretty well carbon neutral. A forest of some given density, over time, will remain carbon neutral. If it gets thicker, the carbon captured is more, but it's also more prone to fires (which obviously then release that carbon).

No, you can get it to sequester carbon if you plant trees (or other plant matter), harvest it, convert it to charcoal, then spread that around. Apparently in that form (biochar) it stays sequestered for a few thousand years: https://en.wikipedia.org/wiki/Biochar

[Syonyk]

Yes, but that's neither geological scale times, nor something nature does. I can make a forest sequester carbon if I dig big holes and bury trees in them, but that's not a particularly natural process either.

Left alone, nature's cycles are mostly carbon neutral.