BRUSSELS — The European Union is bowing to demands from the United States and the fossil fuel industry that it scale back its efforts to fight a planet-warming superpollutant. The EU in 2021 vowed to curb emissions of methane and drew up legislation that forces the oil and gas sector to limit emissions of the powerful greenhouse gas, which is responsible for around a third of the global rise in temperatures since the industrial era. Now, however, Brussels is poised to significantly weaken