Book interview: Green sky thinking

BEING ABLE TO commute vast distances around the planet in a matter of mere hours is a recent gift to humankind. Until the 20th century, we had depended on horses, trains and increasingly the internal combustion engine that propels the automobile. But as our thirst for getting from city to city, country to country, continent to continent multiplied, we came to rely on a self-propelled, heavier-than-air technology that only got off the ground in 1903 when Orville Wright piloted the gasoline-powered Flyer for 12 seconds over a distance of 120 feet.