The planetary zero-impact carrying capacity for humanity is somewhere between 500 million and 2 billion, depending if we want (respectively) a first-world meat-inclusive diet or a fully vegan diet.

Carbon emissions aside, we are indeed a plague upon the planet. Thanks to high tech, we have massively blown past our carrying capacity, and risk lowering the non-high-tech-enabled carrying capacity down into the mere tens of millions or even less. Which bodes very badly if we experience a severe civilizational collapse in the next 10-30 years (as is becoming increasingly likely) that makes building and maintaining high tech impossible.

Edit: this meme is also very problematic. A “collapsing environment” has CO2 production as only a very tiny contribution. It also involves soil degradation, overfarming, overfishing, overharvesting of forests, animals driven to extinction, and all sorts of effects that are DIRECTLY ATTRIBUTABLE to our insanely high population and has almost no extra effect from “the wealthy”.