"I suppose that the US could do away with a lot of its domestic flight
too.
There are a lot of short hop flights between some of the east coast
cities
that are only a few hours drive apart. Washington DC, Baltimore,
Boston,
NYC are all within an area smaller than Belgium or Holland but are all
well
connected by air. "

I agree with that, and also California and the Midwest should have
high-speed rail systems. The problem is that our Republican government
doesn't care about global warming or oil conservation, and won't fund
intercity rail or practical mass transit within cities, so almost all
Americans need a car to get anywhere. The average American uses far
more resources than the average Western European or Japanese, and
transport is the main reason.