Nowadays, when people think of "air pollution," they tend to imagine highly developing countries such as Delhi and Beijing. However, urban areas on the other side of the world are facing the same problems as well, just like Paris.

Paris is currently experiencing what is called an "exceptionally serious" crisis as a massive spike in pollution has become the most prolonged event in the city for a decade.

According to Business Insider, this prompted the city to announce that all public transport will be free for the second day running, and afterward, the Velib bike share and Autolib electric cars were also free to use.

Every Tuesday, the city implemented a system where only half of all its cars are allowed to enter the city center.

On Tuesday, only cars with even-numbered plates could drive in the capital region, while on Wednesday it will be the turn of odd-numbered plate cars. 

Anyone violating this rule will be fined, with 1,700 fines handed out on the first day alone.

The temporary ban placed on half of all vehicles came days after the mayor of Paris pledged, alongside three others, to ban all diesel cars by 2026 in a long-term bid to cut the dangerously high level of air pollution in the capital.

According to IFL Science, the plan is to promote alternative vehicles, walking and cycling. According to Phys.org, the ban is simply temporary and is a way to say that Paris is "no longer tolerating" air pollution and the health problems it was causing.

The current situation has not been helped by the windless conditions across the city, meaning the smog along the capital is not as dispersed as it usually has been.

Air pollution is thought to kill at least three million people globally, with majority of these in cities. More urban centers are forced into action as the public health implications of pumping dangerous gasses and particles into the streets are becoming more common.