Walkers easily travel three miles by foot. Drivers get in their cars to get from one side of the parking lot to the other. Neither quite understand why the other is so crazy, when it's so easy to do things their way.
Unfortunately for the existing mature systems in nature, the rapid expansion of the human bubble is destroying them. Unfortunately for us, we can't exist without them any more than a living person can exist without oxygen or a body can exist without a head. In this sense, it is actually a conceptual error to define the environment as the rest of the biosphere save humans, and think of ourselves as apart from it, since we can't exist without it.