Few things.
Both arable land and fresh water are functions of energy price; with the advent of chemical fertilizers and desalination you can farm pretty much anywhere, it's just a matter of cost which is unprofitable in current market conditions.
Moreover, this idea that everyone should have a house with a backyard is a western pipe dream rather than an actual restriction on human habitability. In New York conditions we could fit the entire population of the planet into Texas.
So yes, these are issues of distribution, refinement of resources, and the fact the current economic model doesn't really promote social goods that aren't profitable in of themselves.