1. A method of managing vehicle emissions, comprising: receiving at least one measurement relating to a vehicle, including a thermal measurement indicative of emissions from the vehicle; detecting an identity of the vehicle and from the identity, determining one or more operating modes available to the vehicle, each operating mode being defined by a specific combination of power or fuel sources; inferring, from the thermal measurement, an operating mode in use by the vehicle; and calculating an emission charge for the vehicle, based on the operating mode.