Jesting aside, it’s a beautiful series. The landscape descriptions sometimes get tedious. But you find yourself missing the old land as the series progresses, an effect woven brilliantly.
Every atmosphere was whorly. The clouds on Vavatch—that’s when I looked it up. The air whale planet is the last one I remember reading it in respect of.
To be fair, I had to look up Vavatch. It's been a while since I read the last Banks book. And it really was the last :(
I find the KSR's descriptions of landscapes one of the best bits of all of his books.
There was a series of books that Terry Pratchett co-authored, called The Science of Discworld, where a bunch of wizards were creating a planet, and it went through a bunch of phases, punctuated by E.L.E. asteriod impacts. I think it was a fanciful chronicle of early Earth.
As well as the science ones there a Folklore of Discworld which could easily have been a throwaway novelty but was a great unsight into the real folklore that Pratchett references and lampoons.
The hard part is explain is how photosynthetic life survived. The Slushball Earth hypothesis holds that there was a band of thin ice near the equator. This has some severe problems though. For one, it isn't climatologically stable. The oceans in SE were covered by "sea glaciers," which were floating glaciers thicker near the poles, which flowed to the equator. These flowed due to the weak hydrologic cycle, with ice experience net sublimation near the equator. These would have overridden any areas of thin or nonexistent ice.
A hypothesis that is getting more traction is that narrow equatorial rift seas (like the Red Sea) would have prevented inflow of the sea glaciers enough for thin-ice refuges to exist. These kind of seas probably existed, because this was occurring as the supercontinent Rodinia was beginning to break up.
Wow, that makes imagining conditions on the Snowball Earth all the more fascinating, thank you.