Of course, there's been a lot of suggestions along the lines of "Add climate zones". I'm responsible for one of them myself. After looking through the notes, I realize that they are, of course, planned.
What occurs to me, though, is that when we have the infrastructure for displaying climate information, there is also the opportunity to combine a lot of information and projections about future climate change in a very accessible way.
I for one think it would be very neat to use this opportunity. Besides possibly fitting with the theme of recolonizing earth in the future, it is also a fascinating way of allowing people to really get a sense for what the abstract changes predicted mean in a concrete sense.
I suppose that modifying the whole set of planet data to be half a meter closer to sea level might be difficult, and I'm not sure how you'd go about hosting this alternate data set. Presumably Futurearth would be distributed in the same way as mars, moon, and hypothetical planet data.