I've been trying to figure out how much carbon is produced when a single person travels on Amtrak. Amtrak has some stats on their WhistleStop website which say a 300 mile weekly roundtrip produces 1152kg/CO2, which would be 1152/52/300 = 0.073kg/mile.
But the BBC says that UK rail travel costs between 80g and 165g per passenger kilometer. So that's 128g to 264g per mile, or 0.128kg to 0.264kg.
So something seems fishy.... Amtrak has an older fleet of (presumably) less efficient engines. How do they handily beat even the lowest figure from the UK's modern rail network?