Given the stuff he's collected, he appears to be traveling all over the world. You can't take a train across oceans. I don't know why Europeans seem to want to derail every discussion of anything into "why can't the world be more like Europe," but have you looked at an equal area map of the whole globe lately? (https://www.esri.com/about/newsroom/wp-content/uploads/2019/...). The overwhelming majority of the world is not Europe. Vitalik is Canadian. All of continental Europe seems to fit roughly east of the Hudson Bay when shoved into Canada. Some other person in this comment string is talking about how easy it is to get around all the major cities in Spain by train. That's great. Spain is 2/3 the size of Texas. Getting around North America isn't nearly the same. Presumably, Vitalik flies more than he uses trains because he has a finite lifespan and wants to devote more of his time living as a nomad to being where he is going rather than in the act of getting there.

As for carbon footprint, I'm not going to comment on the moral quality of his choices, but the dude founded a cryptocurrency. Once you've done that, I don't think much else you can do short of also founding an oil company is going to make your carbon footprint worse than it already is.