China has become the world’s biggest polluter, taking over from America, according to a new report. It’s thought the amount of greenhouse gas being produced by China hadn’t been estimated properly — and it’s making much more than thought.

University of California experts warn that unless something is done, China’s increasing pollution will stamp out the good work in other countries. They think China probably became the world’s worst polluter in 2006-2007. Until now it has been generally believed that the USA was the country with the worst pollution.