to radically reduce consumption, use nuclear power and buy additional renewable power from other, less densely populated, countries. The power per area of nuclear power facilities, by the way, is about 1,000 watts per square meter -- much higher than that of renewables. When it comes to the land area required, nuclear power stations and uranium mines are relatively small and unobtrusive. If the world is to move to a sustainable energy future, one that also limits the risk of global warming, each country will need to work out its own post-fossil-fuel energy plan. And the numbers will have to add up. Any such plan should anticipate the lifestyle aspired to and the energy consumption required. Today, the average European consumes 120 kilowatt-hours per day. That's more than double the world average, but lifestyle changes and determined switches to more efficient technologies for transport and heating might enable a modern European quality of life to be enjoyed for an energy cost close to the current world average, perhaps 60 kilowatt-hours per day a person. What sort of building project is required to deliver that much energy? For illustration, imagine getting one-third of that energy from wind, one-third from desert solar power and one-third from nuclear power. To obtain 20 kilowatt-hours per day from wind, one person would require roughly 330 square meters of wind farm -- or, to put it another way, would need to share a big 2-megawatt turbine with 600 friends. To get the same power from deserts