Related to cloud cover: one of the biggest uncertainties in climate models is how to cater for the albedo effect also known as cloud feedback. It goes something like this:

1) The most potent greenhouse gas is water vapor (not CO2) 2) Increased temperatures result in more water vapor (simple evaporation) 3) Water vapor forms clouds 4) Clouds are white and reflect incoming solar radiation

A lot of models have to make big assumptions about the strength of this negative feedback loop, and the assumptions have a big impact on the output of the models.

https://en.wikipedia.org/wiki/Cloud_feedback

Conversely, further increased evaporation > even more water vapor > increased precipitation > fewer clouds.

Also, clouds reflect sunlight > less warming, but clouds reflect IR > less cooling.

It’s a really complex interaction that doesn’t have a clear global maximum as each region has a slightly different impact and they all interact. Atmosphere dust is one of the biggest drivers here and dust alone involves a lot of non linear feedback loops.

"further increased evaporation > even more water vapor > increased precipitation > fewer clouds." No. You can't get fewer clouds from more water vapor, that's not how equilibria work.

Clouds are dependent upon the particulate matter in the air, which is reduced by precipitation. You still get cloud formation without that, but the air ends up very supersaturated.

https://en.wikipedia.org/wiki/Cloud_condensation_nuclei

Thanks for the clarification. Always seemed a bit too quick and neat a causation.

But as you say the bigger picture is still worrying - and i am not sure that disregarding cloud formation there isn't still certain aerosols hanging around changing things for the worse after heavy air traffic - it's hard to gauge from the Abstracts of papers i just skimmed, but something seems to be happening : https://link.springer.com/article/10.1023/A:1006600107117 https://www.researchgate.net/publication/279155481_Impact_of...