Considering how much land, resources, and wildlife the human race has exploited and taken advantage of for our own selfishness and greed, giving up some tracts of land we no longer need or use and giving it back to nature is the least we can in the name of environmental restoration.
Considering how much mankind has occupied and exploited the lands, resources, and wildlife of this planet, giving some land that humans no longer need or use is the least we can do to restore some of the destruction we have caused to this planet. I will always be for restoration.
An area where the population is decreasing should be wiped clean and allowed to foster growth of the natural land. It does not make sense to leave vacant buildings which are really places for rats to foster and nothing else. It is more pleasant to look at natural scenery. It is also better to rebuild these natural resources.
This really isn't a question about what should or should not happen. The fact is that depopulated areas -- truly depopulated areas -- automatically go back to their natural state when nature reasserts itself. Proof that this is automatic? Just look what happens if you don't weed your grass or mow your yard for a few weeks. Look what happens to buildings that are left uncared for. Look what happened to the Mayan temples taken over by tropical rain forest. Should we clear out North Dakota and give it back to the bison? Fat chance. How many guns are there in North Dakota. Even areas that are not becoming depopulated are going back to their "natural state." Look at the increasing population of white tail deer and coyote in the eastern half of the United States. Look at the resurgence of wild animals around Chernobyl.
On all accounts for the modern age which is based solely on energy needs, should more land area of the planet revert back to its natural state, for example: forests or dense woodland on near shorelines provide cover during tsunamis and storms.. .. .. .. .. .. .. .. ..