While ive got a handfull of videogames in my brain with environmental themes a lot of them tackle environmental problems in a sort of captain-planet esque way or in a vague way which doesn’t confront a specific large scale problem. Neither of which is what I feel your looking for.
Two tabletop RPGs come to mind, which would provide good frameworks for allowing people to explore this.
- Farewell to Fear: A Progressive Post-Fantasy RPG
- Blue Planet (Several editions)
I have played neither however. I know them mostly by reputation. Both are on my “too play” docket.