The asteroids and the Outer Solar System are completely uninhabitable by human beings. However, with sufficient energy and knowledge, it will be possible to create colorful, spacious and wealthy habitats even beyond the orbit of Pluto. The System is full of sources of energy. Humanity is capable of accumulating unlimited knowledge.
Poul Anderson shows us these processes in two future histories: Tales Of The Flying Mountains and the Harvest of Stars Tetralogy. These are his most hopeful works. Mankind can put aside its present conflicts and reach not initially for the stars but certainly for everything within a two light years radius of the Sun. We stand at the threshold.