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Recent papers have emphasized two things about global climate models: They proved to be very poor at predicting future climate, and they don't even agree with each other in most of their outputs other than global temperatures, which they all got wrong.
Now, in a peer reviewed paper published in the journal Atmospheric Chemistry and Physics, modelers describe a big problem causing lack of accuracy in models; that is, assumptions in the models concerning clouds and aerosols have been off by as much as 100%. In short, they show there is no good way to model clouds and aerosols yet, and guesstimates of those factors are often way off.
Observations show that even when conditions are identical one day clouds will form and the next day they won't. They might form in one area and not in another. The source of this variation isn't well understood but may have a lot to do with the randomness of aerosols in the atmosphere.
There is relatively little real world data on the types and concentrations of aerosols and no way to predict these factors.
Hindcasting of models shows that clouds and aerosols are a big source of variability in the climate.
One theory about climate feedback is that clouds cool the surface. Clouds form from rising water vapor, which is increased with higher temperatures. Precipitation has a big effect on heat exchange in the atmosphere, too. So it may be that warming of the surface leads to more clouds and precipitation, which in turn cools the surface resulting in an overall neutral or negative feedback. This could have profound effects on the overall climate, but with no way to model clouds it's not predictable.
Now, in a peer reviewed paper published in the journal Atmospheric Chemistry and Physics, modelers describe a big problem causing lack of accuracy in models; that is, assumptions in the models concerning clouds and aerosols have been off by as much as 100%. In short, they show there is no good way to model clouds and aerosols yet, and guesstimates of those factors are often way off.
Observations show that even when conditions are identical one day clouds will form and the next day they won't. They might form in one area and not in another. The source of this variation isn't well understood but may have a lot to do with the randomness of aerosols in the atmosphere.
There is relatively little real world data on the types and concentrations of aerosols and no way to predict these factors.
Hindcasting of models shows that clouds and aerosols are a big source of variability in the climate.
One theory about climate feedback is that clouds cool the surface. Clouds form from rising water vapor, which is increased with higher temperatures. Precipitation has a big effect on heat exchange in the atmosphere, too. So it may be that warming of the surface leads to more clouds and precipitation, which in turn cools the surface resulting in an overall neutral or negative feedback. This could have profound effects on the overall climate, but with no way to model clouds it's not predictable.
