One thing is certain: we need to wean ourselves of fossil fuels. Why? Many reasons. Among the leading ones, 1) fossil fuels are a limited resource (we'll run out of them some day); 2) China, India, Brazil, and other burgeoning economies will need fossil fuels; 3) for the time being we'll continue to need fossil fuels to power our modes of transportation; and 4) we depend on plastics but as yet th…