A raging fire in the Borneo rainforest sends dense smoke into the sky. Set to clear land for farming, the fire ignited dried out peat, which can smolder underground long after the flames are gone. Besides destroying habitat for birds, reptiles, and other wildlife, such fires yield vast amounts of CO2 into the atmosphere. As a result, Indonesia now ranks third among nations, after the U.S. and China, as a source of greenhouse gases.