For millions of years humans existed in harmony with nature. But the Industrial Revolution, and the exploration and development of energy to fuel that revolution, began a period of ever-growing fossil fuel combustion that resulted in greater water pollution, air pollution, deforestation, and growing atmospheric carbon dioxide concentrations. Nuclear energy, which was supposed to be the solution to these problems associated with fossil fuel production and combustion, turned out to present an equally great threat to the environment in terms of safety and waste disposal. Because almost no energy source is totally benign, and all the major energy sources have unwanted drawbacks, billions of dollars are being spent each year on scientific research to find ways to lessen the environmental impact of the sources in use, to make the more benign sources more cost-competitive, to improve the energy efficiency of...