The train feels abandoned by time—rattling, freezing, and dimly lit, with every compartment showing decades of neglect.

As more people reconsider how they travel on a warming planet, a small but growing contingent in Europe wants to switch from high-emission, short-haul planes to more climate-friendly sleeper trains.

I booked a shared sleeper cabin on an overnight train from Austria to Italy in October 2022. I thought a sleeper train would be the best way to maximize my days while exploring Europe. A few surprises ...