Cities' Strategies To Combat Air Pollution

Air pollution is a pressing issue that affects cities worldwide, with over 90% of people worldwide breathing in air that the World Health Organization (WHO) considers potentially harmful. The main sources of air pollution in urban areas are vehicles, power plants, and crop burning. To combat this, cities are implementing a range of initiatives to reduce traffic pollution and improve air quality. This includes encouraging the use of public transportation, electric vehicles, and bicycles, as well as promoting urban gardening initiatives and the adoption of green roofs and renewable energy sources. Some cities are also experimenting with car-free days and banning diesel cars from city centres. These initiatives aim to not only improve air quality but also make cities more sustainable, liveable, and healthier for their residents.

Stricter testing and controls on vehicle emissions

Vehicle emissions are a major contributor to air pollution in cities. To improve air quality, cities can implement stricter testing and controls on vehicle emissions. This can include:

Regular Emissions Testing

Cities can mandate regular emissions testing for all vehicles, ensuring that they meet certain standards for pollutants such as hydrocarbons, carbon monoxide, and nitrogen oxides. This can be done through a statewide enhanced inspection and maintenance program.

Strict Emission Standards

Cities can implement strict emission standards for vehicles, setting limits on the amount of pollutants they are allowed to emit. These standards should apply to all types of vehicles, including passenger cars, heavy-duty trucks, buses, and construction equipment.

Incentivizing the Use of Electric and Hybrid Vehicles

Cities can offer incentives for residents to switch to electric or hybrid vehicles, which produce fewer emissions than traditional petrol or diesel cars. This can include tax incentives, reduced parking fees, or access to high-occupancy vehicle lanes.

Encouraging Regular Vehicle Maintenance

Cities can educate vehicle owners about the importance of regular maintenance to ensure optimal performance and reduced emissions. This can include tasks such as tune-ups, oil changes, and keeping tires properly inflated.

Implementing Congestion Charges

Cities can introduce congestion charges for drivers, especially in busy areas such as city centres. This discourages people from driving and reduces the number of vehicles on the road, leading to lower emissions.

Promoting Alternative Modes of Transportation

In addition to incentivizing electric vehicles, cities can promote alternative modes of transportation such as public transportation, cycling, and walking. This can include investing in public transportation infrastructure, creating more bike lanes, and making pedestrian-friendly zones.

Vehicle bans in city centres

Madrid, the Spanish capital, is a prime example of a city that has prioritised cyclists and pedestrians over motorists. The city introduced new driving restrictions in its centre, aimed at reducing air pollution by up to 40%. The oldest and most polluting vehicles are banned from the city centre, with drivers facing fines if they breach the rules. This move is expected to reduce noise and encourage more cycling in the city, improving air quality and creating a cleaner environment.

Paris has also taken a stand against air pollution by banning cars in many historic central districts during weekends and imposing odd-even bans on vehicles. Additionally, Paris has made public transport free during major pollution events and encouraged car- and bike-sharing programmes. The city has reclaimed road space from vehicles, transforming it into areas for trees, pedestrians, and cyclists. These efforts have led to a significant drop in nitrogen dioxide, particulate matter, and carbon dioxide levels.

Oslo, the Norwegian capital, is another city making strides towards removing cars from its central streets. Oslo has closed off certain streets in the centre to cars and removed parking spots, replacing them with cycling lanes, benches, and miniature parks. Data shows a marked decline in air pollution and a decrease in trips made by car, with an increase in walking, cycling, and public transport use. Oslo's efforts towards a car-free city centre aim to improve air quality and enhance social interaction.

Delhi has also implemented vehicle bans to tackle air pollution. The city has banned all new large diesel cars, taxis, and SUVs, and experimented with alternating bans on odd and even number plates. These measures have been taken to reduce traffic pollution and improve the health of Delhi's residents.

These cities provide successful examples of how vehicle bans in city centres can effectively reduce air pollution and create healthier, more sustainable urban environments. By prioritising pedestrians, cyclists, and public transport, cities can make significant strides towards improving air quality and the well-being of their residents.

Promote e-mobility and public transport

Electric vehicles and public transportation are key to reducing air pollution in cities. Electric vehicles have seen significant technological advancements in the past two decades, making them more affordable, environmentally friendly, and efficient than traditional petrol or diesel cars. They produce zero emissions, are quieter, and can be conveniently charged at home.

To promote the use of electric vehicles, cities can introduce fiscal and regulatory policies that encourage their adoption. For example, providing incentives such as tax breaks, offering discounted parking or toll rates for electric vehicles, and investing in infrastructure like charging stations. Additionally, cities can lead by example by transitioning their public fleets, such as buses and taxis, to electric alternatives.

Public transportation is another powerful tool in the fight against air pollution. It helps cut congestion and reduces vehicle emissions. Buses, trams, subways, and trains are more affordable than private cars and often provide discounts for specific groups, such as children, students, and seniors. Making public transportation more accessible and efficient can encourage people to leave their cars at home. Cities can achieve this by increasing the number of routes and stops, improving connectivity, and offering integrated ticketing options, such as e-tickets through mobile apps.

Some cities are already taking innovative approaches to promote e-mobility and public transportation. For instance, Freiburg, Germany, has a comprehensive network of bike routes and an efficient and affordable public transport system. One suburb, Vauban, discourages car usage by restricting parking near homes and offering cheaper housing and free public transportation to residents who choose a car-free lifestyle. Copenhagen, Denmark, has prioritized bicycles over cars, resulting in more cycles than people in the city. Large areas of the Danish capital have been vehicle-free for decades, and the city plans to become carbon neutral by 2025.

By implementing policies and initiatives that promote e-mobility and public transportation, cities can significantly reduce air pollution, improve health outcomes, and create more sustainable urban environments for their residents.

Greener cities with more urban gardening

Air Quality Improvement

Plants act as natural air purifiers, absorbing gaseous pollutants through their leaves and drawing in heavy metals through their roots. Some plants, like the silver birch, yew, and elder, are particularly effective at capturing ultrafine particles, including those from traffic emissions. Urban gardens can also serve as indicators of air quality, with plants acting as bioindicators of pollution levels. For example, a study in Copenhagen used kale and rapeseed plants to monitor air pollution associated with heavy metals and metalloids, finding higher levels of traffic-related elements near busy roads.

Community Development and Education

Urban gardens provide spaces for community interaction and environmental education. They promote healthy eating, raise awareness about air pollution, and encourage sustainable practices. The process of growing and cultivating plants can foster intergenerational connections and enhance mental and physical health.

Sustainable Food Production

Urban agriculture reduces the distance food needs to travel, thereby decreasing transport emissions. It also ensures local production and access to fresh produce. However, it is crucial to address the risks associated with soil contamination in urban areas. Heavy metals, such as lead, zinc, and copper, as well as petroleum products and pesticides, can be present in the soil near industrial areas and busy roads. Conducting soil analysis, using elevated structures with clean soil, and incorporating compost are essential measures to ensure the safety of urban-grown food.

Green Infrastructure

In addition to urban gardens, cities can incorporate more green infrastructure, such as green walls, screens, and roofs. These vertical gardens help capture ultra-fine and fine particles of pollutants, reduce nitrogen dioxide concentrations, and lower air temperature spikes.

Policy Support

Cities can play a pivotal role in promoting and supporting urban gardening initiatives. This includes providing resources, offering guidance on plant species selection, and ensuring access to clean soil and irrigation water. Additionally, policies that encourage the development of community gardens, green spaces, and agricultural projects can contribute to the overall greening of urban areas.

By embracing urban gardening and adopting strategies to mitigate the risks associated with air and soil pollution, cities can create healthier, more sustainable environments for their residents while also contributing to the global fight against climate change.

Incentivise citizens to use electric vehicles

Electric vehicles are a crucial component of the transition to sustainable mobility. To incentivise citizens to use them, governments can implement a range of policies, including:

• Purchase subsidies: Direct financial support for citizens to purchase electric vehicles can be an effective way to encourage their adoption. This can take the form of tax credits, rebates, or grants. For example, the Chinese government has offered subsidies of up to CN¥ 60,000 (~US$9,281) for private purchases of new battery-electric vehicles.
• Tax exemptions: Removing or reducing taxes on electric vehicles can make them more affordable for citizens. This can include exemptions from registration taxes, road taxes, or value-added taxes (VAT). In some cases, these exemptions may be temporary, phasing out over time as electric vehicles become more prevalent.
• Access perks: Governments can also provide perks for electric vehicle owners, such as access to bus lanes, free or discounted parking, and waivers on charging or toll fees. These perks can make electric vehicles more attractive and convenient for citizens.
• Differentiated taxation: Implementing differentiated taxation on vehicles and fuels based on their environmental performance can encourage citizens to choose electric vehicles over more polluting options. This can be done through higher taxes on conventional vehicles and fuels, or providing tax breaks for electric vehicle owners.
• Charging infrastructure support: Investing in charging infrastructure is crucial for encouraging electric vehicle adoption. This can include direct investment in publicly accessible chargers or providing incentives for citizens to install charging points at home. Ensuring convenient and affordable charging options can help address range anxiety and make electric vehicles more appealing to citizens.
• Regulatory instruments: Governments can implement regulations and standards to encourage the adoption of electric vehicles. This can include fuel economy and tailpipe emission standards, zero-emission vehicle (ZEV) mandates, or low-emission zones that restrict the entry of polluting vehicles into certain areas.
• Incentives for manufacturers: Incentives can also be provided to vehicle manufacturers to encourage the production and sale of electric vehicles. This can include tax breaks, grants, or other financial incentives to support research, development, and manufacturing in the electric vehicle industry.

Frequently asked questions