Harnessing the Earth, the atom and the leaf
With the world’s energy needs growing rapidly, can zero-carbon energy options be scaled up enough to make a significant difference? How much of a dent can these alternatives make in the world’s total energy usage over the next half-century? As the MIT Energy Initiative approaches its fifth anniversary next month, this five-part series takes a broad overview of the likely scalable energy candidates.Beyond wind and solar power, a variety of carbon-free sources of energy — notably biofuels, geothermal energy and advanced nuclear power — are seen as possible ways of meeting rising global demand. But many of these may be difficult to scale up enough to make a major contribution, at least within the next couple of decades. And a full accounting of costs may show that some of these technologies are not realistic contributors toward reducing emissions — at least, not without new technological breakthroughs.Biofuels have been an especially...