Global warming could be far worse than we initially thought after a dramatic rethinking of the role that clouds play.
Researchers, writing in the journal Science, say a doubling of carbon dioxide in the Earth’s atmosphere could see global temperature rise by up to 5.3C – far warmer than the 4.6C older models predict.
The researchers, led by Yale University, analysed satellite data and found that clouds have much more liquid in them than ice – which has been assumed until now.
Clouds with ice crystals reflect solar light stopping it reaching and heating the Earth’s surface, liquid cannot do the same job.
Increased carbon dioxide will also stop clouds from changing to a heat reflecting state in the future, researchers say. If so it will be far harder for countries to keep to their promise of keeping global warming below 2C as agreed at the Paris climate summit last year.