New data shows that China’s emissions of carbon dioxide fell in 2025, the first full year to show such a decline. The drop, measured by the Carbon Brief website is only 0.3%, but climate campaigners say it could signify a milestone for the world's biggest emitter of greenhouse gases. The BBC's Climate Editor Justin Rowlatt explains why China has made a shift towards clean energy through decades of investment, and how its policies contrast with other big emitters such as the United States. New