How Major Cities Around the World are Fighting Air Pollution

Climate change is the organisational and systemic challenge of our times, but we can’t afford to take our eyes off the fight on other environmental fronts either. One of the more ubiquitous problems, and one that we can see affecting us right before eyes (and noses), is that of urban outdoor air pollution.

By Aaryaman Aashind

We have all seen those images of cities covered in smog and the multitude wearing face masks for fear of breathing in the outdoor air. It brings to mind dystopian imagery from 20th-century novels. Awareness about the dangers of air pollution is at an all-time high. We know that unseen particles can wreak havoc on our long-term health and cause problems such as heart disease, strokes, respiratory illnesses and cancer. In our capacity, using a face mask is a good bet against unseen particulate matter.

The problem is complicated because several factors contribute to unsuitable air quality such as automobiles, factories, cooling and heating appliance, burning solid waste, and burning coal or biomass for cooking and heating. According to the WHO, only twenty per cent of 4300 cities surveyed live in conditions that pass air quality guidelines. Leadership in cities are cognizant of the problem, and many major cities have started experimenting with potential solutions. Even though there can be no one-size-fits-all solution, there is reason to hope that we arrive at ad-hoc solutions soon.

Let’s take a look at some of the measures that major cities around the world have taken to combat outdoor air pollution.


Beijing’s long-standing fight against air pollution started in 1998. A UN-led team of international and Chinese experts have compiled a report that details the city’s evolving steps towards clean air.

By 2017, the level of concentration of particulate matter in Beijing’s air had fallen by 35%. This was a first; because no other city in the world has ever managed to reduce air pollution levels so drastically.

This result was thanks to a combination of measures and initiatives that confronted the problem from every angle. All this while, the city continued to grow its economy at a rate of 6.5%.

How was this sustainable development achieved?

Over twenty years, a comprehensive air quality management system has taken shape. This system includes legislative backing and proper enforcement, implementation of well-researched and strong local standards, regular monitoring at every level, and high levels of public awareness.

This system has been complemented by economic incentives to curb pollution and financial support to those who helped the cause.

For example, once it was realized that coal combustion was a major source of particulate matter, the Government incentivised households to switch from coal-based heating to electricity-based heating. They offered to subsidise the purchase of electrical heating equipment by taking on two-thirds of the cost. They also provided a maximum discount of seventy-eight per cent on the heating electricity bill to those who made the switch. Needless to say, many took the Government up on the offer.


In November 2019, the air pollution levels in Delhi were so dangerous that the city had to declare a public health emergency. These levels were twenty times worse than what the WHO considers being safe for human requirements. 

This was despite the city’s Graded Response Action Plan. The GRAP is an emergency response plan formulated by the Government by the direction of the Supreme Court of India. Unlike Beijing’s proactive control measures, the GRAP takes effect when pollution sees a spike.

This plan is responsible for measures such as banning the use of diesel generators, the closure of a thermal power plant near Delhi, banning the use of petroleum coke, and augmenting the use of BS-VI fuel- a fuel that may be the world’s cleanest petrol.

The GRAP operates under the auspices of the EPCA, a Government body that was constituted to ensure that the city’s buses and autorickshaws use CNG instead of diesel in 1998. By December 2002, there were no buses in the city that still burned diesel.

Even though preventing vehicular emissions went a long way, the most frustrating problem faced by the city is seasonal pollution in the winter months. Several crop fields surrounding Delhi are burnt in winter to make room for the new harvest. Compounded by slow wind speeds and dense cloud cover, the city’s atmosphere turns almost toxic.

To help restrain pollution levels in winter, Delhi implemented the odd-even policy from November 2 to November 14, 2019. Under this rule, only cars with license plate numbers that end in even numbers can ply the roads on even-numbered dates. The same goes for odd-numbered cars on odd-numbered dates. The odd-even policy works to improve air quality when Delhi needs it the most.

Los Angeles

Los Angeles suffers from one of the poorest qualities of air in the USA due to its geography. Thick perpetual smog has almost become characteristic of the city. The problem arises because Los Angeles lies between the inward-blowing wind from the Pacific Ocean and the high mountains to the east of the city. The polluted air has nowhere to go but stay where it is. 

Unlike other major cities, the main adversary in Los Angeles’ fight for clean air isn’t particulate matter but Ozone. High levels of Ozone can permanently damage human lungs, cause asthma attacks and increase the likelihood of early death. Authorities know that something has to be done to improve the city’s liveability.

Los Angeles’ fight started as long ago as 1947 when the city established its Air Pollution Control District. Their mandate was clear, help the city get rid of its smog. However, scientific research in the problem was still in its nascency. It took decades to realise that vehicular emissions were a major contributor to the city’s smog, and it wasn’t until the Clean Air Act, 1970 was passed that automobiles had to comply with anti-smog measures. Today, the city’s air is estimated to be approximately 60% cleaner than in the 1970s. 

The goalposts have shifted since then. Now, Los Angeles is looking at implementing zero-emissions technology by 2030. One of the key aspects of reaching this goal is controlling emissions from port activity. Towards this end, the Clean Air Action Plan was adopted with the specific mandate to reduce emissions from ships, trucks, trains, terminal equipment and harbour crafts that operate in and from the Los Angeles Port Area.

The Clean Air Action Plan involves wide-scale consultation with industry stakeholders and public outreach to formulate new standards and implement new technology. Thanks to the CAAP and various state-level regulations, NOx and SOx particles in the air have dropped by 56% and 97% respectively since 2005.

Going forward, the CAAP has set targets such as reducing the presence of greenhouse gases to 40% below 1990 levels and deploying more than 100,000 freight-carrying vehicles that can operate with zero-emissions by 2030.


Environmental problems do not recognise boundaries, and neither should the authorities in charge. With ever-increasing ease of global communication, cities can learn from each other and move towards a sustainable future together. The question should no longer be if the problem can be solved, but how fast can we solve it. Even though there is a lot to be done, we have come a long way, and maybe we won’t have to move to Mars after all.