[dionhaefner]

Climate models are vastly complex, and you need to bring together many experts from many disciplines to write and maintain one, and analyze the output. This seems to lead to the simplest methods coming out on top. Perhaps it could be solved with better abstractions (a lot of very smart people are trying).

[ChrisRackauckas]

That's precisely what composability solves. We're seeing in CLIMA that using more general highly optimized solvers can greatly decrease the `f` cost count moreso than focusing on really low level optimizations. Especially in things like the land model where you can have many stability issues (such as large complex eigenvalues which happen to work very poorly with multistep methods, even BDF), the ability to split the develop of the time stepping to a huge community of 100's of developers without losing performance gives something where more optimal methods for a domain arise and are found. Yes, the standard is to use something simpler. No, it's not even close to optimal and that is something that is being made very clear.