Cities and Climate Change: Air quality
Cities and Climate Change is a series of articles exploring how cities and urban areas are affected by climate change. Besides introducing the challenges cities are facing, our aim is also to discover how cities can be the drivers of change. Therefore, we will also introduce solutions and best practices of enhancing cities’ adaptive capacity and resilience.
This series’ first article gave an introduction to the effects of climate change in urban areas. Cities are concentrating people, consumption and economic activities. Hence, urban areas are also responsible for the vast majority of greenhouse-gas emissions. However, cities also have the potential to tackle these challenges through well-thought-out urban development plans, ideally considering all environmental, social and economic aspects. Cities aim to provide appropriate services and a decent level of quality of life to their citizens, but this endeavour is often disrupted by the adverse effects of climate change. This article is aiming to discover the interlinkages between climate change and urban air quality, and its impacts on urban dwellers’ everyday life.
Figure 1 - Urban air pollution - Source: Guardian - Gavin Rodgers / Alamy
Air pollution and climate change are a strong correlation with each other. Human-induced climate change is reducing air quality, while air pollution due to the emissions of anthropogenic activities, such as air combustion of fossil fuels in vehicles, power plants, industrial activities, transportation, agriculture and domestic activities are acting as drivers of climate change (Patella et al, 2018). Air pollution is causing serious health concerns, and damage to the environment and ecosystems while having economic impacts too, with a cost of over 330 billion euros - mainly due to healthcare costs (European Commission).
Poor air quality combined with extreme weather events, such as heatwaves and wildfires have severe effects on human health. Risks for premature mortality are increasing due to indoor air pollution, indoor pesticide use or exposure to volatile organic compounds (IPCC, 2022). As was already discussed in the previous articles, the urban population is especially affected by the adverse effects of climate change. According to an estimation carried out by the European Environment Agency, 96% of urban citizens were exposed to particulate and fine dust levels exceeding guideline levels set by the World Health Organization (Patella et al, 2018). The excess concentration of fine particulate matter is held responsible for 238.000 premature deaths in Europe (EEA, 2022). Particulate matter (PM) is a mixture of solid and liquid droplets, coming in different sizes – below 10 micrometres are able to enter our lungs and cause serious health problems (European Environmental Agency). Air pollution can also be associated with higher ground-level ozone and nitrogen-dioxide concentrations, and other air pollutants - such as the growth of moulds from flooded buildings and higher humidity levels. (Climate Adapt). Air pollution can potentially lead to health impacts such as cardiovascular, pulmonary and respiratory diseases, or lung cancer. The social and economic costs of climate change are expected to increase in the future. Even though the air quality is improving in Europe, levels of key air pollutants are still exceeding the guideline levels (Patella et al, 2018).
The interlinkages between climate change and air pollution also is providing an opportunity to address these issues jointly, especially in urban areas. Management of air quality in the European Union is aiming to meet the air quality guideline levels set by the WHO. EU’s air quality policy is targeting setting legal limits for the concentration of air pollutants while decreasing emissions through national emission reduction commitments and sector-specific sources, member states’ responsibility is clearly emphasised in the EU policy framework. The Ambient Air Quality Directive is aiming to maintain air quality and reduce health impacts through the development of national air quality plans for 12 key pollutants. These plans are aiming to keep concentrations of air pollutants below guideline levels. The National Emission Ceilings Directive sets reduction targets for 5 main air pollutants, requiring Member States to create air pollution control programmes. Standards and emission limits on sector-specific sources including industrial emissions, road and non-road vehicles, fuels and product design standards. (EEA, 2018). As part of the European Green Deal, the European Commission’s Zero Pollution Action Plan set the goal of reducing premature deaths caused by PM2.5 by 55% compared to 2005 (European Environmental Agency).
To tackle air-pollution-related issues, most of the European cities first identified the key emission resources, hence the main sources of air pollution were further understood. Main emissions are associated with road traffic, residential heating and industry, inland shipping and urban constructions. The measures taken to improve urban air quality often include the improvement of urban mobility, management of road traffic, limiting industrial and residential heating emissions and urban space management (Viana et al, 2020). The improvement of green infrastructure elements to tackle air pollution is debated and is dependent on factors like wind, location, vegetation size and structure. As studies have shown, even though vegetation could be effective in decreasing air pollution, it could increase air pollution in other locations due to reduced wind speed. Therefore, spatial plans have to take pollution dynamics into consideration when planning for the development of green spaces. (EEA, 2020).
Barcelona’s Superblock initiative was already mentioned among the best practices for tackling extreme urban temperatures. The district of Sant Antoni is also a great example of tackling urban air pollution – the traffic of cars, motorcycles and non-electric buses were restricted in the area, resulting in an 82% decrease in the traffic volume. The ban on polluting mobility resulted in a decline of NO2 concentrations by 33%, and a drop in noise pollution by 4,1 decibels, while boosting social life and bringing economic benefits, too.
Figure 2 - Superblock in Barcelona - Source: oneearth.org
Poland’s capital is aiming to tackle air pollution through the ‘Breathe Warsaw’ project. With the installation of the air quality sensor network, the city aims to better understand the emission sources. Furtherly, the program aims to provide technical assistance and policy research in the designing of low-emission zones, advancing cleaner heating systems, exchanging best practices and raising awareness through clean air campaigns. There are several examples of how European cities are fighting to reduce air pollution. To tackle pollution of residential heating, Dublin banned solid fuels for heating, and a ban on bituminous coal was also planned in national legislation. Madrid, for example, planned low-emission transportation zones with a ban on some diesel vehicles. Transport-related measures may include the promotion of public transport and cycling or imposing congestion charges as Milan did for reducing traffic in central areas. In the case of Berlin, emission targets were set for inland shipping with the requirement of retrofitting cruise ships with diesel particle filters (EEA, 2018).
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European Commission – Environment, Air
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EEA, 2022: European Environmental Agency – Web report: Air quality in Europe 2022 https://www.eea.europa.eu/publications/air-quality-in-europe-2022/air-quality-in-europe-2022
European Environmental Agency: What is particulate matter and what are its effects on human health? https://www.eea.europa.eu/help/faq/what-is-particulate-matter-and
Climate Adapt: Evidence on Climate and Health – Air pollution
EEA, 2018: Europe’s Urban air quality – re-assessing implementation and challenges in cities; EEA Report No 24/2018; https://www.eea.europa.eu/publications/europes-urban-air-quality
European Environmental Agency: Air pollution: how it affects our health
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