I mean....yes. Yes, your carbon footprint is smaller by travelling slower. But you need to be in an extremely priviledged position to be able to afford travelling this way, both financially and time-wise. Cross-atlantic is obviously quite extreme, but even within Europe a train is not really a viable alternative for a lot of people, when I go to visit my family the choice is either a ~£100 Ryanair ticket for a 2 hour…
I agree with your main point! I want to state that upfront so that you don't think I'm arguing about the current situation, apart from addressing specifics. You will have to add some time to flying scenario. You have to arrive early to the airport to go through security (2 hours?), you have to wait for your luggage after landing (30 minutes?), and since airports are usually located outside of the city center you have…
https://news.ycombinator.com/item?id=19562152
The whole thread may be of interest to you, it is about Sweden wanting to re-surrect night trains: