Just because Isayama doesn't show any consequences, doesn't mean you can't infer they didn't happen. The world is already fucked with only 80% of it destroyed, and planting trees doesn't really change anything. This type of thinking is just pure objective permenance.
What we can infer is there's no significant effects, it changed nothing about their every day lives and nobody talks about it.
Both the manga and anime show that Paradis gets destroyed way after any of the relevant characters died, and it assumes that the Rumbling is the core reason, but its only semantics just as much as apparently me bringing up well established real world consequences of the Rumbling is.
The anime in particular attempted to put it further in the future to make Eren's actions seem to have a longer impact for Paradis, but the manga makes it seem as if the attack happened not terribly long in the future.
Honestly, that change is almost on par with the final ending theme's cope that Eren & Mikasa reunited that shippers cling to. The manga is canon, Eren seemed to only buy enough time for his friends to live in peace and then he never reunited with Mikasa at all. Half-assed anime-only attempts to appease fans who wanted Paradis to survive and for there to be a happy ending only serve to diminish the original story's impact, better to just take AoT for what it was, a black pill.
Not to mention, Paradis are not really innocent given with the deaths of Eren and Floch, the Yaegerists are still alive and kicking, explicitly shown to be running the island.
Details slip my mind after I watch shows, but I don't recall Yaegerists being in control, Historia was to my memory, which seems to be why the traitors were allowed back instead of killed.
Regardless, what's wrong with that anyway? Their goals were only to ensure Paradis' survival, sounds like they
should be in control if they're not, right?
Again I would not consider the environmental damages of the Rumbling if Isayama didn't have the titans be walking carbon dioxide generators.
It's not unfair to consider it, but to say with certainty they'd usher in the literal end of the world is too far considering how they already finished 80% of the job. The last bit--say Paradise is a low-ball 1% we can exclude--just 19% more, abd that's the difference between utter annihilation and no significant impact? I doubt it, but either way it just means Isayama is a bad writer, which we can all agree on for the most part.
Hell Isayama seems to be aware since he just later says that its okay because they're planting trees. So he acknowledges it, even if its flimsy at best.
Was that in the original manga? I don't remember it. But nobody suggested there was no damage, just the extent is being argued, a total collapse of the ecosystem was never hinted at, but destruction generally obviously is an effect.
Isayama falls into the trap of many stories that try to take the turn of disasters that would destroy the world, and don't even think about the realistic consequences that would happen.
It's a real problem in battle shonen especially. One Punch Man is especially egregious, I think, but it gets a pass for being comedic.
I am going to nitpick this analogy since if you wanted a good point, you should've had the roles reversed given how Israel has so many first world countries sucking their dick.
No analogy is perfect, it's not 1:1, but the fact remains that some enemies want you dead because of who you are, what you believe, or what your past is; they will
never seek true peace, ever, and you should not trust them to the extent that you are ever at their mercy.