VIA Rail has a page that compares various aspects, including emissions, of the train vs. the car vs. the plane for some common central Canadian routes.

The fine print is interesting:

Train emissions calculator

The formula used to calculate train related data emissions is: (Litres of diesel fuel consumed X Emission Factor) / average of seats available on the selected route = Kg of CO2 equivalent per seat. The emission factor of 3.00715 Kg of CO2 equivalent per Liter of diesel No. 2 was used. The fuel consumption for each selected route was calculated using an average of real-time fuel consumption as measured by the Witronix technology over a 12-month period. The emission factor for diesel No. 2 is calculated by Environment Canada as part of its National Inventory Report (2011 submission) and takes into consideration the global warming potential of CO2, CH4 and N2O.

Flight emissions calculator

Number from Zerofootprint Flight emission calcultor for Air Canada used.

Car emissions calculator

For the calculations, a mid-size sedan with a combined fuel consumption rate of 10.0 Liters per 100 km was used, considering an average capacity of 4 passengers per vehicle. The distances are calculated in Kilometers using Google Maps. The formula used to calculate car related data emissions is: (Litres of gasoline consumed X Emission Factor) / average # of seats = Kg of CO2 equivalent per seat. The emission factor of 2.500 Kg of CO2 equivalent per Liter of gasoline (Tier 0) was used. The fuel consumption rate for a mid-size vehicle is an average calculated for mid-size type vehicles from the 2013 Fuel Consumption Guide developed by Natural Resources Canada. The emission factor for gasoline is calculated by Environment Canada as part of its National Inventory Report (2011 submission) and takes into consideration the global warming potential of CO2, CH4 and N2O.

I don’t know if these are the right calculations to be using, but kudos to VIA for including them.

It would be nice if VIA create a more general-purpose emissions calculator that worked for all of their routes.