I think you are all overlooking other factors. For instance when hydrogen fuel cells are perfected (whatever time that may be) and we have an essentially unlimited fuel supply. We American will start driving huge vehicles again. Except this time it will not stop at SUVs but we will be driving around in huge hydrogen powered monstrosities the size of a current RV.
All that fuel consumption, along with the water consumption of billions of extra people on the planet, will drain all the extra water out of the ocean.
Plus I like the filling up of the Grand Canyon idea. Those of you who say it will not fit just have to remember you can jump up and down on it alot and MAKE it fit!