cars and pollution

There is a lot of pollution in the world but I will talk about that of cars. I find that there are far too many cars and traffic therefore a lot of pollution. The city of Lyon has set up a system to control the cars. they have different numbers 1, 2, 3 and 4 depending on their pollution levels. the 1 pullut less than the 2 and so on, one day these the only 1 which have the right to roll another than the 2 ect. but already thanks to the confinement there is a lot less pollution and the nature resumes it is right we could steal dolphins in the lagoons of Venice.