Mankind has inhabited new areas when it made sense to do so. In fact, most of earth's land surface is _not_ inhabited, and large parts, such as the poles, have

Mankind has inhabited new areas when it made sense to do so. In fact, most of earth's land surface is _not_ inhabited, and large parts, such as the poles, have never been. We are not even close to covering everyones immediate needs in a sustainable way. 85% of the global energy production relies on fossil fuel.