Aviation biofuel is mostly a distraction. Any serious effort to decarbonize the transportation industry would focus on a scalable system, presumably high-speed rail.
(And whoever is thinking about being a smartass, don’t you dare come at me with bullshit about trans-ocean flights, they obviously can’t be take by train, but biofuel is still utterly incapable of supplying even only ocean flights. It’s not ever going to be a viable product. We’d be better off trying to scale up carbon capture than try to use all our arable land to grow crops for fuel.)
I see Mint as the more reasonable option that keeps 98% of the advantages of Ubuntu, with less of the crazy. I was a xubuntu user a decade ago, but have been very happy with Mint xfce since I switched.