I have four children. I expect to have at least that many grandchildren one day. I anticipate the world they inherit to be one filled with technical wonders, as mine has been, and also filled with the richness of life and human history. I fully expect their lives to include consumption of energy at a rate an order of magnitude or greater than mine has been; they will travel the world, and perhaps beyond this planet, with a comfort I never knew. They will build and create in both the virtual and physical worlds, they will have freedoms and capabilities beyond our current imaginations. And I know, without a doubt, that fossil fuels cannot sustain this world I envision for my grandchildren - both because the climate and other pollution implications of that level of fossil consumption would be fatal to that future world, and simply because fossil carbon represents a finite resource whose day has been wondrous, but is passing.