We don't often recognize the humble activity of cooking for the revolutionary cultural adaptation that it is. But when the hearth fires started burning in the Paleolithic, humankind broadened the exploitation of food and initiated an avalanche of change. And we don't often associate cooking with drilling for oil, but both are innovations that allow us to tap the sun energy accumulated in organic matter. Alfred W. Crosby, a founder of the field of global history, reveals how humanity's successes hinge directly on effective uses of sun energy. But dwindling natural resources, global warming, and environmental pollution all testify to the limits of our fossil-fuel civilization. Although we haven't yet adopted a feasible alternative--just look at the embarrassment of "cold fusion" or the 2003 blackout that humbled North America--our ingenuity and adaptability as a species give us hope.