There might be no solution... But what I think personally, in a guess, as it is probably impossible for any single person to figure this out alone, that there is probably no one solution fits all.So,,, what is the solution to all of this mayhem? Haven't you said all this once before?
I think population decrease is a must. But go figure how to do that with billions believing in a myriad of divinities. And I think change of life is a must too, because the average one person in the EU or USA is definitely not counting in terms of pollution as the average person in the Amazon or some regions in Africa.
Ideally, we humans would accept we are only one kind (no races) so nobody would care about the stereotypical caucasian disappearing (if global warming continues current trend the fair skin ones better hide underground). Ideally all flags and passports go to the garbage and we accept migration is part of our past and future and we don't own the earth, we are part of the belongings of the earth.
But in reality, 20% of population might be too selfish for any changes, 70% follows whatever is told, rest is not enough...
Not too positive. Except we might not need to do anything if a big enough asteorid comes again our path. It can be next year.