Wow, why, as someone who voted ecologist last election, couldn't think of that earlier
I would love to see this victory, since it's a global challenge in the real world.
How to implement it genuinely is of course the trickier part
I think the real problem would be how to implement that as a Victory... ie something that one civ accomplishes.
Environmental victory seems more like a series of "International Projects" (where the actions of other civs increase the costs)
I'm personally hoping for:
1-Time will still be in as a default
2-Military Domination
3-Scientific(+cultural*) superachievement
4-[Cultural super achievement (ie like a Utopia... If cultural is not part of the spaceship win)]
5-DiploReligious(+cultural**) Domination (maybe with a vote for/against.... you can't vote against someone you have a DoF with with..although you could abstain)
6-[Cultural domination..like in BNW...unless cultural is part of the Diplo religious win]
*hopefully there are a number of civics required for a Spaceship win.. seems like you would have to reorganize society to persuade them to support a massive that wouldn't even get there for decades.
**high culture over someone forcing them to vote for you
Given only one is cut and one is new... I'd guess there isn't a Utopia victory...
science hopefully is redesigned to be science+culture superachievement (civics, buildings and policies opened by them required as well as techs and things opened by them)
religion is new (and incorporates parts of the old diplo I'm hoping)
Military and Tourism victory are basically the same