Book excerpt: Acclaimed Caldecott Artist Molly Bang teams up with award-winning M.I.T. professor Penny Chisholm to present the fascinating, timely story of fossil fuels. What are fossil fuels, and how did they come to exist? This engaging, stunning book explains how coal, oil, and gas are really "buried sunlight," trapped beneath the surface of our planet for millions and millions of years.Now, in a very short time, we are digging them up and burning them, changing the carbon balance of our planet's air and water. What does this mean, and what should we do about it?