Almost every human activity requires external sources of energy. Affluent societies are increasingly dependent upon energy to maintain their lifestyles while developing countries require more energy to improve their standards of living. As both population and GDP have grown across the globe, so has energy use: at present people use about ten times as much energy as in the early 1900s, and this amount is projected to double by 2050 and at least triple by 2100. Most of our energy today — about 85 percent globally — comes from fossil fuels. These fossil fuels pose a danger to our society for two primary reasons: there is increasing evidence that their greenhouse gas emissions are closely linked to serious climate changes, and the sources for this energy pose a dangerous threat to our national security. In the face of increasing energy demand, can we face the daunting task of reducing fossil fuel consumption through alternative fuels and conservation?