Climate-warming emissions from burning fossil fuels have remained flat for a third year in a row in a development that suggests a shift to a greener global economy is happening faster than previously thought. A striking drop in carbon pollution in the US, where emissions fell back to what they were in 1992, helped to keep global CO2 levels in 2016 virtually unchanged from the two previous years, the International Energy Agency said. “This is a very welcome development,” said Fatih Birol, IEA executive director. “It appears we now have the first signs of an established trend of flat emissions as a result of natural gas replacing coal in major markets and renewables becoming more and more affordable.” Mr Birol said it was especially significant that emissions stayed flat during a period of sustained global economic growth, currently about 3 per cent per annum.