text: "Be afraid. Be very afraid." That is the overriding sentiment of a recent article titled "Global Warming's Terrifying New Chemistry," written by Bill McKibben, an environmental activist and founder of 350.org, an organization dedicated to stopping the use of all fossil fuels. McKibben portrays methane, the primary component of natural gas, as a greenhouse gas potentially more dangerous than carbon dioxide because methane is more effective at trapping heat in the atmosphere.