Heads in the Clouds

The latest climate change models are a good deal more pessimistic than the earlier versions (https://www.theguardian.com/environment/2020/jun/13/climate-worst-case-scenarios-clouds-scientists-global-heating). And it's all down to clouds. Clouds can sometimes cool the atmosphere but ,at other times, they keep the heat in, intensifying the 'greenhouse effect'. For this reason, in earlier models, the effects of clouds were assumed to be neutral. New evidence now suggests that clouds will generally intensify global warming. A number of reliable agencies are now predicting that, if atmospheric carbon dioxide levels double those of pre-industrial times (and they are well on their way!), average world temperatures will increase by 5 degrees Celsius. This is more than double the somewhat arbitrary 2 degrees that experts have suggested might be 'safe'. If they are right, it will  result in runaway changes in the planet's climate, that we would have no hope of mitigating. Things are looking considerably more urgent.