The government has revealed that seven members of the Swiss delegation to the COP climate conference in Glasgow travelled by train.
The journey took 16 hours and stopped in Paris and London.
The move was designed to set an example. Under current rules, flying would have been allowed as the land trip did take more than 6 hours.
But members of the Federal Council did take a plane as they are not there for the whole conference.
The Environment Department says ministers do need to represent the country around the world, and so using a plane for them was justified.
The government says all the CO2 emissions will be offset.