Complex systems tend to self-balance. Say you introduce an invasive predatory species to an island. That species would kill and fuck en masse as long as there's resource to do so. Once they've depleted it they will promptly dwindle in numbers and balance will be restored. Of course in such a scenario maybe the prey would go extinct but that's beyond the point.
So yeah, I find it very funny when I hear "we are killing the planet" - no we aren't. We are killing ourselves and quite frankly I couldn't care less for humanity as such. We probably deserve a "mass extinction" event just to sober up a little and cut some fat. It's too bad we'll take a lot of other unique lifeforms with us as well, but hey, maybe they don't "deserve" to be living either, if they are wiped out as easily by a bunch of crafty apes.
As for Greta Thunberg. Well, let's forget she's a well off little white girl that's being used as a puppet by some fag. The problem with her is that she's antagonizing the shit out of the world, pitting all kinds of people against climate change as a subject just because they feel attacked. She is throwing shit all over the place and this will never ever fucking work in proving an argument, let alone changing people's minds that it's time to act and making them join your efforts. "How dare you?"... How dare you shit on all the efforts scientists and hundreds of people made before you to establish a civil dialog about climate change. We are getting there, you have to be delusional to think it'll take just a couple of decades to completely ditch fossil fuels and become carbon emission free all of a sudden. Inter and Milan can't build a fucking stadium for over a decade and a half ffs...
At this point I think only Bill Gates knows what he's doing. Elon Musk is living in la la land with his 100% renewable romance. Greta here wants to sue countries (France and Germany of all, lol) and "punish" people for "stealing her childhood"... So Bill Gates, of all people, works on a new nuclear reactor design that works with spent fuel - the only actual working solution to the emissions problem. Dude is actually way smarter than many of the false prophets that take the spotlight lately.