CitarCO2 emissions per passenger...
Journey:    Out & back by plane...    Out & back by train...
London to Paris by Eurostar    3.5 hours, 244 Kg/CO2    2.75 hours, 22 Kg/CO2
London to Edinburgh            3.5 hours, 193 Kg/CO2    4.5 hours, 24 Kg/CO2
London to Nice                       4 hours, 250 Kg/CO2    8 hours by Eurostar+TGV, 36 Kg/CO2
London to Barcelona            4.5 hours, 277 Kg/CO2    Eurostar then overnight sleeper, 40 Kg/CO2
London to Tangier                       5 hours, 435 Kg/CO2    48 hours by Eurostar, sleeper trains & ferry, 63 Kg/CO2