>Because if all that comes from renewables on Earth, there'd be no sunlight left for the biosphere. If it comes from nuclear or offworld sources, then per therm

>Because if all that comes from renewables on Earth, there'd be no sunlight left for the biosphere. If it comes from nuclear or offworld sources, then per thermodynamics all that energy becomes waste heat and you have a second sun worth of heat to deal with. Suck enough greenhouse gasses out of the air and you'll need that waste heat