Yes, we do. For all practical purposes, earth's gravity well serves as a boundary for material resources at scale. More importantly, the input of polluting ma

Yes, we do. For all practical purposes, earth's gravity well serves as a boundary for material resources at scale. More importantly, the input of polluting material into earth's obviously very limited ecological system is limited. You simply cannot pollute as much as you want, so getting more stuff from the asteroid belt or whatever doesn't help.