St. Petersburg Times: A decade ago environmental attorney Marco Monroy approached food giant Nestle with a novel proposal. If the company converted boilers at its ice cream factory in Chile from coal to natural gas, it could cut emissions of carbon dioxide by up to 50 percent. It wasn’t an easy sell. The conversion would cost $100,000, and on top of that natural gas was more expensive. But Monroy had a surprising pitch. He explained that the reduced carbon emissions could be sold on the world market …