Parisians are getting free public transport to combat the city’s dangerous smog

Paris is in the grip of its worst pollution crisis in a decade, and on Thursday, for the third consecutive day, the local government banned half of French drivers from using their cars in the city and made all public transport free. Paris is not the only major European city coping with high pollution levels this week. Lyon and other cities in France have experienced poor air conditions, with the pollution problem crossing the channel into London as well.

Here’s what you need to know.

What’s the problem?

The metropolis is coping with an extended bout of dangerous winter pollution and smog this week. Airparif, the French capital’s air pollution watchdog, said the pollution levels in the city are the worst in a decade.

According to Airparif, the problem has been exacerbated by cold weather and virtually no wind to push the clouds of pollution out of the city. Instead, exhaust fumes, smoke from wood fires, and other pollutants have been trapped in the city’s atmosphere.

What’s the solution?

The authorities have imposed an alternate ban on cars entering the city and 22 communes in the inner suburbs for the last three days, and have made all public transport free. The ban targets half the city’s license plate numbers on alternate days, with odd-numbered cars banned on Tuesday and Thursday and even-numbered cars banned on Wednesday.

The free public transport is costing the city an estimated 4 million euros a day.

It is the fourth time in 20 years that Paris has had to impose this sort of traffic ban in response to dangerous pollution levels.

What’s the long-term solution?

In January, France will introduce a new obligatory system where all vehicles will have to display a sticker showing its level of emissions. In the future, rather than a blanket ban on all vehicles, only those with specific sticker colors will be ordered to leave their cars at home during future pollution spikes.

Paris Mayor Anne Hidalgo recently announced her intention to ban all diesel cars from the City of Light by 2025. Her ambitious pledge was joined by the mayors of Mexico City, Madrid, and Athens. The city is also looking to phase out diesel engines on public buses throughout its quarters.