All the ores, crude oil, and other feedstocks are found in nature. How much processing is needed to lose the “natural” aspect? Where is the threshold?
Any invasive species can roll over a local ecosystem with ease. And it doesn’t require humans to bring some in. Even the native ones can become too numerous if something happens to the predators, e.g. a disease; some big cats, some beasts-of-prey, I don’t remember which ones, carry in their genome a marker of massive viral infection that, if I remember correctly, almost wiped the whole species.
And then there are the blue-green algae which ate enough CO2 and farted enough O2 to change the climate in global scale…
