I'm not actually sure what the solution you're proposing is?
Even if you completely eliminated air travel (with no replacement - which is not realistic), you'd just reduce emissions by a mere 2%. Not a trivial number given the scale, but it's far from a "solution to our climate problem". (For comparison, the larger transportation sector including cars is is 16% of emissions. Cars alone are 12%.) [1]
It also turns out to be a very hard problem to solve. We don't have the tech to build an electric airliner yet, and given how hard it's been just to get a single high-speed rail line from SF to LA I'm not betting trains are going to be in a place to practically replace aviation in the US anytime in the next few decades.
Pretty much just proposing giving people some options. Right now they have few.
Right now in North America on an enormous amount of routes there's pretty much no real alternative to driving or flying and on many others where a train does exist it's so poor in quality that few use it.
If rail was a real option then more people would use it, and that would be transferring people from a relatively much higher CO2 emission form of transport to a lower emission one. That's a win.
Every where I look I see data that shows that the CO2 emissions per user are dramatically lower for train than air travel.
Now clearly on some big routes flying is a must and train would be so incredibly lengthly that it would be a misery, but there's tons and tons of shorter routes where train would work really well, competing well against car/bus and air travel.
If one wanted to get aggressive about it, once the infrastructure as in place, one could do what France has done and to ban short haul flights.
Even if you completely eliminated air travel (with no replacement - which is not realistic), you'd just reduce emissions by a mere 2%. Not a trivial number given the scale, but it's far from a "solution to our climate problem". (For comparison, the larger transportation sector including cars is is 16% of emissions. Cars alone are 12%.) [1]
It also turns out to be a very hard problem to solve. We don't have the tech to build an electric airliner yet, and given how hard it's been just to get a single high-speed rail line from SF to LA I'm not betting trains are going to be in a place to practically replace aviation in the US anytime in the next few decades.
[1]: https://ourworldindata.org/ghg-emissions-by-sector