Innovative Strategies For Reducing Pollution In Urban Environments

Cities are major contributors to pollution, with over 80% of urban residents exposed to poor air quality. To reduce pollution, cities are adopting sustainable mobility practices, such as encouraging the use of public transportation, walking, and cycling, as well as implementing low-emission zones and intelligent traffic management systems. Urban gardening and green spaces are also being utilized to absorb pollutants and improve air quality. In addition, cities are transitioning to clean energy sources and promoting the use of electric vehicles to reduce emissions and combat climate change. These combined efforts are crucial in improving the health and well-being of residents and protecting the environment.

Encouraging the use of public transport, walking and cycling

Encouraging the use of public transport, walking, and cycling is an effective way to reduce pollution in cities. Active travel is considered the most sustainable form of personal transport, and it has been proven to improve public health and quality of life in urban areas.

Walking and cycling can help reduce physical inactivity, which causes one million deaths per year in the European Region. Active transport can also help to reduce air pollution, which claims more than half a million lives annually. According to the World Health Organization (WHO), a 30-minute walk or 20-minute cycle on most days reduces the mortality risk by at least 10%. Active commuting is associated with about a 10% decrease in the risk of cardiovascular disease and a 30% decrease in type 2 diabetes risk.

Cities can facilitate the use of public transport by creating attractive urban spaces that are well connected to transport infrastructure. Making walking and cycling to and from hubs and stops easier and more pleasant will also encourage people to use public transport. Digitalization and mobility apps can also make urban mobility systems more efficient, but they cannot compensate for underdeveloped public transport.

To further encourage walking and cycling, cities should focus on redesigning urban spaces to meet daily needs, such as accessing jobs, education, and healthcare, within distances that can be safely covered by active mobility means and public transport. The implementation of infrastructure for safe walking and cycling is crucial, as well as trip-end facilities like changing rooms at workplaces and secure parking for bikes.

Green spaces, parks, and trails also play a vital role in promoting walking and cycling. Schools should be made safely reachable by walking and biking, and children should be educated about the importance of regular exercise and the environmental impacts of traffic. Additionally, reducing car dependency through better land use, efficient public transport, and disincentivizing driving can lead to a significant increase in walking and cycling.

Using zero-emission vehicles for public transport

Zero-emission vehicles (ZEVs) are an essential component of city strategies to reduce pollution and improve air quality. Light-duty cars and trucks produce 40% of transportation CO2, so transitioning to zero-emission alternatives is crucial to combat climate change.

California's Approach

The California Air Resources Board (CARB) has implemented the Zero-Emission Vehicle (ZEV) program as part of its Advanced Clean Cars package. This program aims to control smog-causing pollutants and greenhouse gas emissions from passenger vehicles in California. The state aims to meet its health-based air quality standards and emission reduction goals by encouraging the use of zero-emission cars and fuels.

Queensland's Strategy

Queensland's Zero Emission Vehicle Strategy 2022-2032 sets targets to increase the adoption of zero-emission vehicles. By 2030, 50% of new passenger vehicle sales are targeted to be zero-emission, with a shift to 100% by 2036. Additionally, all eligible government fleet passenger vehicles are planned to be zero-emission by 2026. Furthermore, starting in 2025, every new TransLink-funded bus added to the fleet in South East Queensland will be a zero-emission bus, with the same initiative being implemented across regional Queensland from 2025 to 2030.

Benefits of Zero-Emission Vehicles

Transitioning from internal combustion engine vehicles to zero-emission vehicles brings multiple benefits. It helps reduce greenhouse gas emissions, improve urban air quality, and enhance public health. Additionally, it supports the creation of more sustainable jobs in growing sectors, such as the renewables industry. Zero-emission vehicles also contribute to quieter neighbourhoods and streets, improving the overall quality of life for residents.

Financial Support

Queensland's Zero Emission Vehicle Rebate Scheme offered financial assistance to households earning up to $180,000 per year. The scheme provided rebates of $3,000, later increased to $6,000, to eligible households to reduce the upfront costs of purchasing zero-emission vehicles. This initiative successfully boosted EV uptake, with a fivefold increase in registered EV cars in Queensland as of July 2024 compared to the start of the scheme.

Creating green spaces and urban gardens

Urban green spaces and gardens are an effective way to reduce pollution in cities. This method, known as "urban greening", involves integrating vegetation and plant-based infrastructure into urban environments. Urban greening has gained popularity as a potential mitigation method for air pollution. Plants improve the balance of carbon dioxide and oxygen in the air, and they are capable of removing and dispersing airborne pollutants.

There are various elements to urban greening, including parks, green roofs, living walls, parklets, sustainable drainage systems (SuDS), and custom planters. These green interventions play a crucial role in reducing air pollution and creating healthier cities.

Plants have the ability to absorb airborne pollutants and release oxygen, improving the balance of gases in the atmosphere. Trees, in particular, act as natural filters, removing pollutants and particulate matter from the air. Living walls and green roofs can also help reduce pollution by capturing and filtering pollutants before they enter the air.

The placement of plants is important to maximise their air-purifying capabilities. For example, trees placed strategically near roads and in areas with high pollution levels can help disperse pollutants and reduce their concentration.

In addition to reducing air pollution, urban greening has a range of other benefits. It can help to regulate temperature, reduce energy consumption, enhance aesthetics, and provide habitats for wildlife. Urban greening also has positive effects on mental health and well-being, creating a connection with nature and reducing stress.

While urban greening is a powerful tool, it should be noted that it is not a standalone solution. It needs to be applied in conjunction with efforts to reduce the sources of pollution, such as the implementation of low-emission zones and the reduction of vehicle emissions.

Implementing smart traffic management schemes

Smart traffic management schemes are an essential part of a city's strategy to reduce pollution. These schemes use advanced technologies, such as the Internet of Things (IoT) and artificial intelligence, to improve traffic flow, reduce congestion, and enhance road safety. Here are some ways in which cities are implementing smart traffic management to reduce pollution:

• Optimising traffic signal systems: Cities like Taipei, Taiwan, have implemented intelligent adaptive traffic signal systems that use software to optimise traffic lights and improve traffic flow, reducing vehicle delays and idling, which are major contributors to air pollution.
• Reducing stop-and-go traffic: Strasbourg, France, has successfully reduced emissions and improved air quality by implementing initiatives to minimise stop-and-go traffic. This type of traffic is a significant source of pollution, as vehicles constantly accelerate and decelerate.
• Traffic monitoring and data analytics: Cities such as Charlotte, North Carolina, are investing in traffic monitoring systems that go beyond managing congestion. By using advanced data analytics, Charlotte aims to identify different types of vehicles and make informed decisions about traffic control to reduce pollution.
• Promoting eco-friendly mobility options: Municipalities play a crucial role in encouraging eco-friendly transportation options. This includes optimising electric vehicle (EV) charging networks, reallocating street space for cycling and walking, and gradually transitioning to electric buses.
• Integrating smart infrastructure: London, for example, aims to introduce newer generations of smart street infrastructure to enhance data gathering capabilities. This includes the use of smart sensors and artificial intelligence to identify vehicles and drivers, improving traffic management and reducing environmental impacts.
• Autonomous vehicles and connected corridors: San Francisco is investing in infrastructure to support autonomous vehicles, which can help improve fuel efficiency and reduce congestion. Additionally, the city's Connected Corridor pilot program uses data from traffic sensors to prioritise public transit and pedestrian mobility, further reducing environmental impacts.

Using renewable energy sources

Renewable energy sources emit little to no greenhouse gases and pollutants into the air. They are also readily available and, in most cases, more affordable than fossil fuels. According to the United Nations, about 29% of electricity currently comes from renewable sources, such as wind and solar power. This percentage is expected to increase, with the International Renewable Energy Agency (IRENA) estimating that 90% of the world's electricity can and should come from renewable sources by 2050.

To achieve the goals of the Paris Climate Agreement and become climate-neutral by 2050, cities need to drastically reduce greenhouse gas emissions by investing in renewable energy sources. This requires a strong energy infrastructure that can reliably supply large quantities of renewable energy. One way to achieve this is by revolutionizing energy systems to generate only sustainable and renewable energy.

Photovoltaics (PV) and Solar Panels

Photovoltaics (PV) and solar panels are two types of conversion technologies that generate energy from sunlight. PV systems generate electricity, while solar panels produce heat energy. PV systems are typically installed on roofs or building facades, allowing for proximity to the consumer and avoiding transport fees and energy losses. However, the implementation of PV systems may be restricted by limited available land or high land costs in cities.

Wind Energy

Wind energy has evolved in recent years but has not yet been widely adopted in urban areas. Some of the challenges include the size of wind turbines, the inability to detect turbulent flows and low wind speeds, noise concerns, and aesthetic controversies. Additionally, there is a need for improved understanding of the aerodynamics of wind and enhanced performance of urban wind turbines.

Bioenergy and Waste-to-Energy

Bioenergy utilizes locally available raw materials, such as agricultural and forestry waste, as well as urban waste streams, to produce energy. This approach offers a constant and reliable energy supply while also providing an attractive solution for waste management in cities. However, the sustainable supply of raw materials may be inconsistent, and there may be concerns about the potential impact of waste incineration plants on air quality and public health.

Geothermal Energy

Geothermal energy is an important source of energy for intelligent energy systems, providing cold, heat, and electricity. It is particularly useful for space heating, room cooling, and hot water in cities. Geothermal heat water pumps are used for individual and tertiary buildings, offering water heating, low-temperature cooling, and heating. Borehole Thermal Energy Storage (BTES) and Aquifer Thermal Energy Storage (ATES) are used for the seasonal recovery and storage of thermal energy.

Smart Grids

Smart grids combine generation, storage, and consumption of energy, using information and communication technology (ICT) to enable real-time communication between utilities and consumers. This results in a more dynamic and sustainable power supply. Benefits of smart grids include more efficient electricity transmission, quicker restoration after power disturbances, reduced costs for utilities and consumers, and increased integration of large-scale renewable energy systems.

Frequently asked questions