Clouds study finds that low climate sensitivity is ‘extremely unlikely’
It is “very likely” that the way clouds change as the world warms will drive further temperature rise, a new study finds.
The response of clouds to a change in global temperature – known as the “cloud feedback” – plays a crucial role in how much the planet will warm. However, estimates of cloud feedback are uncertain. The new study, published in Proceedings of the National Academy of Sciences, uses global satellite observations to reduce this uncertainty.
Taking their findings into account, the authors produce a central estimate of equilibrium climate sensitivity (ECS) – the global temperature change resulting from a doubling of atmospheric CO2 – of 3.2C. They add that low ECS values below 2C are “extremely unlikely”.
Cooling effect of clouds ‘underestimated’ by climate models, says new study
Clouds could have a greater cooling effect on the planet than climate models currently suggest, according to new research.
The paper, published in Nature Climate Change, aims to correct a “long-standing” and “unaddressed” problem in climate modelling – namely, that existing models simulate too much rainfall from clouds and, therefore, underestimate their lifespan and cooling effect.
The authors have updated an existing climate model with a more realistic simulation of rainfall from “warm” clouds – those that contain water only, rather than a combination of water and ice. They find that this update makes the “cloud lifetime feedback” – a process in which warmer temperatures increase the lifespan of clouds – almost three times bigger.