Your statement about rail being inefficient if using diesel, what do you propose as an alternative?
It is more efficient than trucking which is its main competitors.
We are discussing passenger rail here. It is the VIA thread after all. Not freight. Yes, rail is more efficient to ship freight. It's not more efficient at shipping people. In no small part, because people people require a ton of support when going long distances. Airlines don't need to bring days worth of food and full kitchens to cook in, when flying from Toronto to Vancouver. Drivers don't do that either, unless they are RVing.
As for alternatives? We've had long discussions on how they can decarbonize. You can go through the thread and read those. No point rehashing and regurgitating. My only point here is that current climate policy is going to make diesel long haul more expensive over time. This will happen while electric vehicles are getting cheaper to acquire and more capable. Both on the road and in the air. If there's no change to policy or technology, long haul passenger rail will face some terrible economics and competitive disadvantages. Entirely possible, we see electric coach buses, for example, become very cost competitive on routes like Toronto-Winnipeg or Halifax-Montreal.