From the 1st April 2017 a windscreen sticker is required to drive in Paris, Grenoble and Lyon to reduce levels of pollution. There are six stickers of different colours that identify the levels of emissions produced by your car. You can be refused entry depending on the certification of your car on days where the cities are reaching high levels of emissions. The sticker costs €4.80 for vehicles registered outside of France, but within the EU.
The clean air certificates apply to all cars, motorbikes and lorries. You can be fined upwards of £60 for not complying. Get your certificate here .