It's nice that the studio is going to all this effort to straighten out their shit. Undeleting Batman, replacing or at-least minimizing Amber, downplaying politics to some degree. But even if these things are true and not just wishful rumors, nothing will help if the movie itself is boring.

And it will be boring if it focuses on this topic. There is little in cinema more predictable and less engaging than Captain Planet antics in an adventure film. It's frankly too simple of a plot device that strays FAR into morality prescription like the old Sci Fi copouts in the 50s and 60s. "Man was the true monster," and "the true Villain was misunderstanding" are tired and unstimulating as story devices because they are so expected.

Let's give this a shot:

Atlantis is mad cause ocean dirty. Manta is mad cause Atlantis not mad enough for his liking, so he takes the war to humans through terroristic attacks on beach vacationers. But he's a man of black color fighting for the environment so we have to love and understand him anyway. Those randos he killed were all littering, they deserve worse than the vaporization granted them.

When I hear "will tackle climate change" I envision this kind of stuff, and it doesn't make me interested. Movies as self-important educators of the filthy dumb audience are anti-entertainment. No number of three-point landings from a mach-2 approach that shatters the concrete in the foreground will make me happy to be yelled at for 2 hours by a narrative I saw before you lifted it from a 30-year-old Saturday morning cartoon.