Wall Street Journal: America’s garbage dumps are reaping a windfall from the fight against global warming. But their payday might not be doing much to reduce greenhouse-gas emissions. For more than a decade, the landfill here has made extra profit simply by collecting methane given off by rotting trash, and selling it as fuel. Last year, the landfill learned that doing this also qualified it to earn hundreds of thousands of dollars via a new program that pays companies to cut their greenhouse-gas …