I dont think you can extrapolate from the US as to how global politics will respond to climate change. I'm in the UK, which is a climate-change denying hellscape compared to much of Europe, and we are tons better than the US.
Take a look at China's rollout of high speed rail, and its amazing progress on solar and wind. Actually wind energy in the UK is often the largest source of electricity here.
The USA is, sadly, an outlier for being determined to ignore climate change and hope it goes away...
But to get back to investment stuff, the US is not the majority of the world. Even if it continues to turn a blind eye to short haul flights, other countries will not, especially Europe and China. FSD is definitely going to have an impact there. France has already enacted a law that outlaws short haul flights were less damaging options exist. Others are bound to follow.
There are also people who, regardless of govt policy, will avoid flying. If I was to go to Scotland again, I'd never fly. I'd get a sleeper train, or preferably, let my Tesla do the drive.