Why promoting walking conserves human habitat and makes ecological sense

I'm a dedicated fitness walker; have been for four-plus decades. I was attracted to this article by the headline above (which I have repeated above). It's not just human habitat that's conserved, though. It's the habitat that's critical to the lives of our fellow brethren of Earth (the only planet we have). Sure, it's easier to get inside a car and isolate one's self from the world at large, but that's not what life is about. Walking burns calories, not a fossil fuel. Walking does not pollute the air; motoring about in an automobile does.