The greenest fuels are the ones that contain the most energy per pound of material that must be mined, trucked, pumped, piped, and burnt. [In contrast], extracting comparable amounts of energy from the surface would entail truly monstrous environmental disruption…. The greenest possible strategy is to mine and to bury, to fly and to tunnel, to search high and low, where the life mostly isn’t, and so to leave the edge, the space in the middle, living and green.