The law on CO2 emissions in Switzerland aims to reduce the CO2 emissions from all imported cars and delivery trucks. Cars that exceed the fixed target values of CO2 emissions will be taxed and sometimes quite heavily. This tax, called sanction on CO2 emissions, aims to orientate importers to more ecological cars.
The law differenciates small importers from big importers (more than 50 vehicles a year for cars and more than 6 vehicles for delivery trucks = big importer). As a big importer you can mix the values of the fleet and you pay for the total amount of deviation, the small importer pays for each car.
The law was introcuded in 2012 for passenger cars and in 2020 for delivery trucks. The target values decreased and will further decrease over the years so the co2 emmissions can be reduced.
The law forsees, that the CO2-emission from a specific car from a specific importer can be transfered to a(nother) big importer. This is how the CO2 Emission trading becomes possible.