Space for in-ground interment is a 'requirement' of some religions.  Just think, 8-billion people in the world and still counting.  Obviously, a growing population has created the same problems in other parts of the world.  Over-population has even led to wars, increasing the death rate, without much effect on human population growth.

Let's not forget that when we take up more and more space for whatever people want, we drive indigenous or native species (who evolved here and are already at risk) toward extirpation, if not outright extinction. It is unsustainable to continue altering the landscape to accommodate more and more humans. There are enough examples all around the world to show us that does NOT work. UNSUSTAINABLE.

Learn from Germany and Holland where gravesites are temporary sites -- life is temporary. If religious people believe their spirits go to live somewhere else, then they should not object to a temporary grave for their temporary remains.