Nice article, and nice analysis of the carbon costs of each mode of transportation.
I agree that high-speed rail would have to be rolled out in a way that makes sense. I use Amtrak whenever I can. Being in the Northeast Corridor, I prefer Amtrak to air travel if I'm going from NJ to Boston or NJ to DC. There have to be other point-to-point options that would make sense for high speed rail.
But I think air travel is here to stay. Not sure how to address the environmental impact of that fact, really, unless someone comes up with some way to keep planes in the air with renewable resources. Not sure about who here has given up air travel, but I've read that environmentalist/actor Ed Begley Jr refuses to travel in planes.
I do feel guilty about the amount of air travel I've done. I've flown 1M+ miles over the past 20 years. These days I'm not flying as much, but if someone asks me to go to the West Coast for research before I'm ready to retire, I will fly, no doubt.
In terms of the New Green Deal, I think developing better rail infrastructure is a good idea, but I don't think it will ever remotely negate the need for air travel.