The pledge was among a slew of COP28 announcements on Saturday aimed at decarbonizing the energy sector - source of around three-quarters of global greenhouse gas emissions - that included expanding nuclear power, cutting methane emissions, and choking off private finance for coal power. Led by the European Union, United States and UAE, the pledge also said tripling renewable energy would help remove CO2-emitting fossil fuels from the world's energy system by 2050 at the latest.