Delhi take note: Four world cities to remove diesel vehicles by 2025. [Representational image]Creative Commons

Four cities across the world -- three in Europe and one in North America -- will phase out diesel vehicles by 2025 in order to improve air quality there. Delhi has been trying to implement a similar step, and diesel vehicles over 15 years old are already banned on the streets of the city, which recently suffered from air pollution so bad that schools had to stay closed for several days.

The four cities that will phase out diesel vehicles are Paris, Mexico City, Madrid and Athens, whose mayors on Friday signed an Air Quality Declaration at the C40 Mayors Summit in Mexico City. December 2 happened to be National Pollution Control Day in India.

"These pioneering cities also pledged to incentivise alternative vehicles and promote walking and cycling infrastructure," a statement from the meet said.

"Worldwide, three million deaths each year are linked to exposure to outdoor air pollution according to WHO, with the vast majority of these deaths occurring in cities," it added.

Paris Mayor Anne Hidalgo, the new chairperson of the C40 Cities Climate Leadership Group, was quoted by the statement as saying on the occasion: "Mayors have already stood up to say that the climate change is one of the greatest challenges we face. Today, we also stand up to say we no longer tolerate air pollution and the health problems and deaths it causes – particularly for our most vulnerable citizens. Big problems like air pollution require bold action, and we call on car and bus manufacturers to join us."

Global petition to end diesel vehicles

There is currently a global petition on social activism platform Change.org that urges car manufacturers to phase out manufacturing of diesel vehicles. It says: "The choices that all of us, citizens, consumers and manufacturers, make today will decide what type of air our children will breathe. We call on the motor vehicle industry to help us deliver that air quality transformation."