I think a SimClimate could become a hit. Maybe the dynamics could be gamified for kids, but I bet there are lots of adults who'd also want to just "spend months crossing the steppes" following the seasons pretty much.
There are games for nuclear war and pandemics that are fun and educational about the globe-spanning dynamics of those catastrophes. There are also games like Universal Paperclips that provide an intuition for the exponential dynamics of complex systems.
Seems like there should be a way to fuse these concepts around climate change.