The Climate Change Committee (CCC) commissioned the Centre for Climate Change and Social Transformations (CAST) to review the role of behavioural science, defined as the study of how humans think and behave, in designing effective climate policies.
The first report reviews existing research about the effectiveness of different interventions to promote low-carbon behaviours in eight key areas. The second report draws upon this research to make recommendations for climate policies. Several important evidence gaps are highlighted, and suggestions for future research are made.
The eight key areas reviewed are:
- Diet change – reducing high-carbon foods in people’s diets (e.g. meat and dairy).
- Reducing end-user consumption – encouraging people to reuse and repair goods, recycle, and reduce food waste.
- Aviation demand – reducing how much people fly.
- Adaptation – adapting to a changing climate (e.g. extreme heat or flooding).
- Net Zero skills and careers – helping people develop Net Zero skills and enter Net Zero careers.
- Business leaders and the transition to sustainability – encouraging businesses to be more sustainable.
- Land use and farming – increasing tree-planting on farmland.
- Policy acceptability – increasing the public acceptability of climate policies.
Several areas were omitted where evidence is being collated as part of separate projects or has been collated elsewhere, such as surface transport, energy, and buildings.
In total, 336 academic papers and 62 non-academic reports (e.g. from government or charities) were reviewed. The review prioritised UK-based evidence but drew on international literature where UK evidence was lacking.
2. Key messages
In the eight areas reviewed, low-carbon and climate-resilient behaviours were primarily driven by:
- An individual’s knowledge about a behaviour, their values, and emotions.
- Social factors (e.g. what individuals perceive others do or expect of them, and which social groups individuals most identify with).
- Practical factors (e.g. how difficult or expensive it is to carry out certain behaviours).
Most research explored how effective it is to provide people with information (e.g. about the impacts of certain diets). These information-based interventions tend to be less effective at changing behaviour compared to measures that make green choices and behaviours the default or shift social expectations (e.g. by the government or businesses demonstrating leadership or introducing new policies).
The focus in the evidence base on informational approaches has limited our understanding of whether some interventions are more effective than others, how varying social groups might respond differently to interventions, and how large-scale behaviour change can be achieved.
Overall, the report notes a need for clearer communication of climate policies and more public involvement in policy design. This may be achieved with the introduction of a dedicated public engagement strategy. There is also a need for policies that make low-carbon behaviours easier, cheaper, and more attractive, alongside regulations and incentives to shift behaviour. Generally, interventions are more likely to be successful when introduced in ‘moments of change’, when habits are disrupted and behaviour is more malleable.
The key findings and implications for each of the eight key areas are summarised below.
- Reducing high-carbon foods in people’s diets (e.g. meat and dairy). Providing information about a food’s impact on one’s health, the environment, or animal welfare is not an effective way to change diets in isolation. Information-based interventions work best in combination with other approaches, such as making plant-based foods more available, convenient, attractive, and affordable. Policymakers may achieve this by making plant-based options more visible and the default in supermarkets and restaurants, alongside introducing financial incentives (e.g. reducing the price of plant-based foods).
- Encouraging people to reuse and repair goods, recycle, and reduce food waste. People are more likely to reuse and repair goods (rather than buying new ones) if they have strong environmental values or perceive others to reuse and repair. However, a lack of relevant skills and low availability of repair services are key barriers. There is some evidence that financial incentives might be effective at encouraging recycling (e.g. getting money back for recycling), but more studies are needed to understand if incentives might be effective at encouraging people to reuse and repair (e.g. policies to reduce VAT on repair services). There are minimal real-world trials studying how to encourage people to buy fewer material goods. Policymakers may opt for a combined approach – providing useful information (e.g. skills training for repairs) and providing financial incentives (e.g. making repairs cheaper).
- Reducing how much people fly. People are generally reluctant to reduce how much they fly, as flying is often linked to ideas about success, freedom, and identity. People who are more concerned about climate change are not more likely to reduce how much they fly, but giving information about a flight’s emissions could lead consumers to choose more efficient flights. The public broadly supports taxes that make flying more expensive for frequent fliers (Frequent Flyer Levies), but such measures need to be accompanied by changes to legislation, and government leadership. It is important that policies aiming to reduce how much people fly are perceived as fair for all, and that the need to fly less is communicated consistently. Generally, research about the effectiveness of aviation policies is very limited.
- Adapting to a changing climate. Most people know very little about how they can prepare for changes such as extreme heat, droughts, or flooding, making it important for policymakers to clearly communicate what types of behaviours are most effective in preparing for a changing climate. More research is needed to investigate if regulations can be effective in creating more climate-resilient buildings (e.g. regulations for planners), and helping people make changes to their homes (e.g. interest-free loans for homeowners). There is also a need for more research comparing the effectiveness of interventions for different types of risks (e.g. flooding compared to heatwaves), and further evidence about how to encourage people to change their behaviour in situations like heatwaves or droughts. Policymakers should therefore focus on delivering clear advice tailored to the type of risk, alongside other measures like financial incentives for homeowners. UK-based evidence in this area was limited, meaning more global evidence was used.
- Helping people develop Net Zero skills and enter Net Zero careers. People know little about the type of skills that are needed to achieve Net Zero in the UK, making providing young people with information about Net Zero skills and careers an important first step in encouraging them to choose a green career. To achieve this, policymakers would need to give a clearer definition of what green skills and careers are alongside opportunities to develop these skills. Schools and businesses could play an important role in educating about Net Zero careers, but more evidence must test this.
- Encouraging businesses to be more sustainable. Businesses are more likely to adopt sustainable business practices when managers are aware of climate change and its impacts. Policymakers may therefore seek to educate managers about sustainable business models. Alongside this, businesses often shift to more sustainable practices when consumers demand more eco-friendly products, and their competitors adopt sustainable practices. Market-based policies could be as successful as regulations, but more UK-based evidence in larger companies is needed to determine this.
- Increasing tree-planting on farmland. Providing farmers with financial aid might encourage increased tree-planting. However, grants are often overly complex to apply for, limiting how effective they can be. Simplifying the grant application process could be a low-cost way of increasing grant uptake. The loss of control over land that comes with using grant money is also a concern for farmers. Policies that focus on providing examples of woodland creation by other farmers, and information campaigns and training about woodland creation are likely to be effective, especially when focusing on the profitability of creating new woodland, and engaging the wider farming community.
- Increasing the public acceptability of climate policies. The public generally favour policies that provide grants or subsidies (known as pull measures) over bans and regulations (push measures). However, there are factors that tend to increase support across a variety of policies. People are more supportive of policies that they perceive as effective and fair for all. It is also important that the policy decision-making process is viewed as transparent, and that policies are implemented by trusted leaders. Policies should be designed in line with these principles. Providing information about other benefits (e.g. for people’s health) and involving the public in designing policies can also increase support. Grouping policies in ‘bundles’ may also bolster support, but further research is needed to test this.