If world development is to continue, mid-century energy requirements are daunting. For world development, per capita energy use in the developing world must be brought up to levels in the already developed world. Restrictions on how much CO2 mankind can responsibly put into the atmosphere may complicate the task further. Studies show that by 2050 the world will require an additional 10–30 terawatts (TW) of carbon free power, at least as much additional, as the 10 TW generated today with fossil fuel. This paper suggests that the fusion hybrid is one of rather few possibilities for generating this power economically, in an environmentally acceptable way, and with little proliferation danger.