Air quality: key behaviours report

Report commissioned to identify key public behaviours that have the most impact on improving air quality, and to support future public engagement work. The report focuses on the actions households and the general public can take to support improving outdoor air quality.

3 Overview of key behaviours impacting on Scotland's air quality

3.1 Overview of key behaviours for air quality in Scotland

Our rapid evidence review highlighted that, although there is a large body of evidence on air quality issues and interventions, very little of this literature frames such issues explicitly in behavioural terms. Cowie et al. (2015) noted that no reviews of the impacts of behaviour change on air pollution existed at that time, and likewise we found no review papers specifically tackling the subject. Rather than asking questions about the contribution of householder behaviours to air quality, it is more common for research to be framed in terms of sources of emissions (usually at sectoral level) and the effectiveness of specific policies and interventions (which may contain a behavioural component). Riley et al. (2021) in a review of air quality communication campaigns classifies behaviours relating to air quality in terms of avoidance behaviours (avoiding exposure to poor air quality, such as by staying indoors), contributing behaviours (behaviours that impact on air quality), and civic engagement behaviours (such as engaging in discussions about air quality with family/friends, writing to an MP etc). In common with Riley et al. (2021), we found that the majority of literature taking a behavioural perspective on air quality primarily focuses on avoidance behaviours, with much less on the contributing behaviours that form the focus of this review.

Looking at the literature that does focus on contributing behaviours, our review highlighted a number of challenges to quantifying and comparing the impacts of different behaviours, both in terms of a) emissions of pollutants and b) impacts on ambient concentrations of pollutants. In terms of emissions, we found limited evidence on the individual-level emissions associated with specific behaviours. Part of this may be down to the variability of impacts associated with a given behaviour. For example, the emissions saved by avoiding a car journey will depend on the length of the journey, type of fuel used by the car, driving speed/type of roads, condition of traffic flows etc. (Keyvanfar et al., 2018; Pandian et al., 2009). The emissions saved will also depend on what replaces that journey – for example, if working from home instead of commuting results in extra emissions from heating the home. Impacts of behaviour change on air quality are likely to be even more variable due to the range of different factors influencing air quality (including spatial distribution of emissions, climate and geographical factors, vegetation, regional transport of pollutants etc.) (Jacob & Winner, 2009; Zhan et al., 2018). Due to the complexity of these impacts, studies using modelling techniques to estimate the impact of behaviour change were particularly useful sources of information for the review (e.g., Jamriska & Morawska, 2001). Before-after evaluations of policies or interventions that include a behaviour change element also provide useful evidence, however isolating impacts of behaviours of the public (as opposed to commercial activities and agricultural/industrial production) and establishing causality remains a challenge.

Given these challenges, the review did not find sufficient data to enable ranking of behaviours in terms of their impact. However, it was possible to identify a set of behaviours that are supported by sufficient evidence to be considered 'key behaviours'. We consider these behaviours under four broad behavioural categories (see Table 2). In addition to the six key behaviours identified, we also highlight two additional behaviours to consider. These additional behaviours are those which the evidence suggests can impact on air quality but where the evidence base is less well developed or less persuasive in terms of the magnitude of impacts on air quality specifically.

Table 2: Key behaviours impacting on air quality

Six key behaviours for air quality improvement

Reducing car use

Walking, cycling or wheeling for short journeys

Using public transport instead of driving

Working flexibly or from home

Switching vehicle

Switching to an electric vehicle

Heating the home differently

Burning less at home

Ensuring good practice when burning fuel (including use of efficient appliances)

Additional behaviours to consider

Reducing car use

Using local shops and services

Driving differently

Using eco-driving techniques (including stopping engine when stationary)

When analysing the drivers and barriers to behaviours, it helps to be as specific as possible about what the behaviour is. In this sense, many of the key behaviours above could be broken down into a number of more specific behaviours. At the same time, when considering key behaviours as a focus for public engagement, is it important to distil clear and simple messages about what people can do to make an impact. Our categorisation of key behaviours in Table 2 attempts to balance these competing priorities. The eight key behaviours identified also map broadly onto several of the behaviours explored in a recent survey on public engagement with air quality in Scotland (BMG Research, 2023), which gives some baseline data on the uptake of the key behaviours and perceptions about their impact on air quality.

In the following sections, we outline evidence on the air quality impacts associated with each of the four broad behavioural categories – reducing car use, switching vehicle, driving differently and heating the home differently. For each category, we go on to summarise the evidence on drivers and barriers to uptake of each of the identified behaviours associated with that category, using the COM-B framework. In proposing the set of key behaviours above we recognise that not all of the behaviours are possible for everyone. For example, many people will not be able to work from home, and some people in rural areas may rely on solid fuels to adequately heat their homes in winter. The COM-B analysis reflects these constraints.

3.2 Risks of framing air quality issues in terms of behaviour

Before discussing the evidence relating to the key behaviours outlined above, it is worth highlighting some important points for policymakers to consider when adopting a behavioural lens on air quality issues. Framing environmental protection and sustainability issues in terms of behaviour change is a subject of ongoing debate in the academic literature (Batel et al., 2016; Nash et al., 2017; Somerwill & Wehn, 2022). Whilst there is an increasing recognition of the need for environmental policy to incorporate understanding of the complex social and psychological factors underpinning environmentally (un)sustainable behaviour, critics argue that a focus on behaviour change deflects responsibility away from powerful institutions and on to individuals (Kaufman et al., 2021; Shove, 2010). Riley et al. (2021) note the risk of this perception in relation to public engagement work on air quality. It is important that research and policy focusing on behaviour change avoids placing emphasis solely on voluntary actions of individuals and interventions that focus on education and persuasion. To avoid this, it is useful to view behaviour change from a systems perspective – focusing not on convincing people to do something differently but asking what elements of the current system could be changed to provide supportive conditions for behaviour change. The COM-B framework, and the wider Behaviour Change Wheel, have potential to help combat misperceptions around behaviour change as a political objective, since together they highlight the importance of the structural conditions (including infrastructure, regulation, service provision) that underpin individuals' opportunity to change their behaviour. The Behaviour Change Wheel and COM-B can also help policymakers to identify the intended agents of change from across society (e.g. government, institutions, workplaces, schools, third sector) with responsibility for delivering behaviour change (Rode et al., 2022).



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