Most of our energy comes from fossil fuels, but eventually we will run out. We will not, however, run out of sunshine or wind or waves. The center of the Earth will always be extremely hot, and fuels like switchgrass and algae can easily be regrown. These types of renewable energy--solar, wind, water, geothermal, and biomass--have the potential to power a cleaner future. The countries of North America have always had plentiful natural resources. But...