[jokteur]

I'm sorry, but rail is the lowest form carbon footprint you can find, if you exclude biking and walking.

Also, boarding a train is so much more comfortable and convenient than boarding a plane (no security check, at least in Europe, wide seats, no emergency tutorial, ...). Also the train drops me right in the city center.

I would argue that up to 500 km of distance, high speed train is the best option, then it becomes debatable.

[xnx]

Trains on existing tracks are very efficient at moving weight.

When the tracks don't exist (i.e. in the US) there are billions of dollars of carbon cost (moving earth, concrete, steel) to building new track.

[jokteur]

This study [1] cites a 80 to 280 tCO2 per km of new high speed track laid (it includes bridges, tunnels, ...). Lets lay 700km of new high speed tracks (Orlando to Atlanta). So 700km of high speed track is 56'000 tCO2 to 196'000 tCO2.

Orlando to Atlanta will have sold more than airplane 310'000 seats in December 2023. At 250g per km per passenger, we get to 54'250 tCO2 emitted on this route alone in December. You can see that laying 700km of high-speed tracks that will last more than 30 years before renovation will emit as much as one to four months of flight emissions on the busiest US airplane route.

You can argue about the specifics of this back of the envelope calculation, but flying emit orders of magnitude more tCO2 than any form of transport (on short haul) that even building a whole new high-speed rail route is worth it after a few years of exploitation. Obviously you are not going to convert 100% of passengers to rail, especially in the beginning with spotty transport coverage, but focusing on busy airplane routes (< 1000km) and building high-speed rail is worth it in the medium-long term.

[1] https://uic.org/IMG/pdf/carbon_footprint_of_railway_infrastr...