As politicians debate the dangers of a massive increase in oil carried by rail in North America, railroads and energy producers are considering the same for natural gas. Buoyed by the unexpected success of crude by rail, companies are beginning to consider transporting natural gas as remote drilling frontiers emerge beyond the reach of pipelines, executives said. Natural gas by rail is years away and likely to face strong public resistance after a series of explosive crude-by-rail accidents. But the potentially multibillion-dollar development could connect gas-rich regions like North Dakota with urban centers, presenting an opportunity for railroads, drillers and tank car makers already cashing in from hauling oil on trains. It could also be a cure for environmentally unfriendly flaring, a growing problem in far-flung areas where more than $1 billion of natural gas produced alongside oil is burned off […]