Humanity's Grand Challenge is transforming the world's largest industry from about 80 % fossil to almost 100 % renewable, CO2-emission-free energy sources, as quickly as we prudently and profitably can. This President's Day lecture at Wartburg College, Waverly, Iowa, 22 October 09, explores the imperatives for, and impediments to, doing so. We humans are not good at very-long-term thinking and planning. And we see ourselves as "exceptional", apparently the most clever and powerful species on the planet, therefore "Gott mit Uns" -- "God with Us", or "God is on our side" -- becomes an excuse for denial and delay, as our sacred Earth is transformed in our lifetimes by global warming, ocean acidification, sea level rise, species extinctions, and violent human conflicts. Is "Running the World on Renewables" a necessary and urgent commitment, on our pathway to Earth stewardship ? How may college students engage with these questions ?