China has had a record-breaking year and has installed more solar and wind power in the last 12 months than the rest of the world combined. The speed of this so-called renewable revolution is unprecedented. The country is still the world’s biggest polluter, but for the first time President Xi Jinping has pledged that his country will reduce greenhouse gas emissions. Analysts believe that the country’s emissions are already beginning to flatline and may be close to peaking. The BBC's China