Some wise men (or boys) once said they'd been to the year 3000, not much had changed but they lived under water.
Now if you ask me, that's quite a fucking bug change. How would everyone breath if they're underwater; would we suddenly grow gills? Would gills have to be applied surgically? if so, how would most people afford them? This underwater future is just going to be populated by rich folk isn't it, with the proles being left to drown.
Also if everything is underwater, shirley this means that the ice caps have melted. Again, this is quite a big deal and I don't think it's a problem that should be belittled by saying "not much has changed". Why would anyone take that stance unless they're being sponsored by large corporations who want to hide the fact that global warming is a bad thing.
And what would happen to all the other animals? shirley all the land and air dwelling animals will die, there's no way they can afford the surgery to get gills fixed.
FISH! what about the fish? They'll be everywhere if we're living underwater. It won't be like birds, they fly about way above our heads and don't really cause much of a problem to us. But fish will be all over the place, swimming down the street, and through your windows. Imagine causually walking down the street and suddenly getting twatted in the face by an army of catfish.
And it won't just be the fish. it'll be giant squids, octupus, killer sharks, nemo, THE KRAKEN!
If that's what the year 3000 will be about, then you can count me out yessiree bob!