I remember New York in the '80s as a place with vacant lots that would eventually give over to nature. Weeds would grow up, squirrels would move in. That entropy is gone now. It's too expensive to let a vacant lot go natural.
MobySit down, close your eyes, and think about dogs for ten minutes. On a very clear, physiological, and neurochemical level, your body is changed by these really positive thoughts.
Moby