Behavioural Science to mitigate the planetary crisis

Introduction

Climate change represents one of the most daunting challenges of our time, with far-reaching impacts on global ecosystems, human societies, and particularly, the wellbeing of children. Addressing this human-caused existential threat requires a profound understanding of human behaviours and how to change them.  
The purpose of this document is to highlight the research from behavioural science to first understand how people feel and think about climate change, and then to identify opportunities and strategies to encourage behaviours that contribute to reducing its impact. Climate change adaptation will not be a focus here as it is covered in this section.

Limitations

• Many of the studies referenced used participants from a Western, Educated, Industrialised, Rich, and Democratic (WEIRD) context and so the findings may not always be generalisable to other contexts.
• Many interventions discussed in the literature, while effective, may not be practical especially when considering programmatic limitations. For example, an intervention that requires writing a letter to a future self is not very scalable, but conceptually, may inspire other novel types of interventions.
• A large portion of studies in this field use self-reported measures (e.g. willingness to engage in mitigation behaviour) and therefore may obscure the effects of actual behaviour.  
• Mitigation or pro-environmental behaviours encompasses many different types of behaviours occurring in different contexts. Many of the insights from the studies here may not be easily generalisable or may not even constitute as truly representative of pro-environmental behaviour.
• The example of interventions here should only act as inspiration for development of programmes.

Why focus on individual behaviours?

Climate change is a large-scale issue that may seem to only be solvable with high level policy and regulatory changes, and that individual changes may not be effective at best or may undermine substantive climate policies at worse (e.g. reducing usage of plastic straws vs ending reliance on fossil fuels).

1. Significant Impact of Cumulative Behaviours: The collective impact of individual behaviours is substantial. Research indicates that demand-side strategies, such as changes in lifestyle and social norms in sectors like buildings, land transport, and food, have the potential to reduce emissions by 40–70% globally by 2050. Social movements and lifestyle changes can significantly accelerate climate change mitigation.
    
2. Individuals as Drivers of Systemic Change: People's choices and actions influence larger systems and policies. When individuals collectively demand sustainable options and policies, it can lead to significant systemic changes. This may occur through collective action of social movements or through market signalling of important values.
    
3. The Role of Responsibility and Motivation: Although the concept of the carbon footprint may have originated from oil companies to shift responsibility to individuals, this has paradoxically increased public awareness and motivation to address climate change. People’s growing sense of responsibility is now fuelling a collective movement towards sustainable practices and the eventual reduction of fossil fuel reliance.

While engaging individuals is important, targeting businesses is critical to achieving significant change, and should always be considered when conceptualising country programmes. Many of the concepts discussed here will be useful in convincing business, but also in helping businesses understand how they can make meaningful impact through their engagement with consumers.  

Why should we include low-income countries in climate change mitigation?

The average person in high-income countries emits more than 30 times as much as those in low-income countries. People in the global top 1% of income cause twice as much consumption-based CO2 emissions as those in the bottom 50%. This data suggests that climate mitigation should only be targeted towards high income countries. However:
 

• It's also about individual income: Rich individuals in low- and middle-income countries can still have significant impact on the environment. It is therefore important that their actions are not neglected. Furthermore, a growing middle class typically leads to mirroring the consumption patterns of individuals in rich countries. Implementing mitigation strategies now can prevent this future increase in emissions.
   
• Immediate benefits: Many climate change mitigating activities can have immediate benefits that can still be enjoyed by those with the lowest emissions. For example, several climate mitigation actions can have immediate impact on air pollution, reducing many illnesses and premature deaths.  
   
• Leapfrogging polluting practice: By implementing sustainable practices early, low-income countries can avoid environmentally harmful practices that many developed countries experienced. For example, by leapfrogging past fossil fuel-based technologies, low-income countries can gain energy independence while adopting more sustainable methods of energy generation.  
   

High income individuals, in richer or poorer countries, often have significant influence as consumers, investors and role models within their communities. As such, they should be targeted not just for their personal environmental impact, but also on how they can shift the behaviours of the general public through their influence.  

Climate Cognition: How people think about climate action

Before exploring ways in which behavioural science interventions can be applied to specific areas of climate mitigation, it is important to understand how people think about climate change as well as their general attitudes and motivation towards mitigation. While climate scepticism is generally on the decline, the threats to inaction come from a lack of prioritising climate change as an existential risk.  

Motivated reasoning

Have you ever argued yourself into a decision that you actually wanted but was conflicted on?

Motivated reasoning is a cognitive bias that leads individuals to process information in a way that aligns with their pre-existing desires and beliefs, rather than based on objective evidence. People often interpret or scrutinise climate data and research findings through a lens shaped by their political ideologies, economic interests, or personal values. For example, a meta-analysis of the predictors of climate scepticism suggests that education, scientific literacy, and personal experiences of extreme weather do not actually strongly correlate with acceptance of climate change being man made, suggesting that even when people know it as a fact, they may still either reject the existence of climate change or are not sufficiently motivated to take meaningful action.  

On the latter point, while people may believe in climate change, they may downplay the urgency because the level of effort and lifestyle changes required may be too discomforting, leading to what is known as solution aversion. For example, limiting the pleasure of consumption or the inconvenience of having to use more public transport might lead a person to downplay the risk of climate change. Solution aversion can also occur when certain solutions to an issue have somehow been linked to certain social identities, e.g. wind farms being supported by liberals, leading conservatives to reject the solution. People are motivated to preserve their social identity and will therefore adopt, through motivated reasoning, beliefs that their ingroup already hold in an attempt to strengthen their connection with that social group.  
The impact of motivated reasoning on the minimisation or rejection of the risk of climate change is further exacerbated by dis/misinformation.  
When a person or social group are already motivated to minimise or reject the risk of climate change, misinformation (or more nefariously, disinformation) can further exacerbate the issue by providing ‘evidence’ in support of their pre-existing position. Here, people may even further use confirmation bias, and seek out the misinformation that most supports their position.  

Psychological Distance

Psychological distance refers to the perception that the threat of climate change is a remote issue, separated from the individual by time, space, or social distance. This means that people often view climate change as an issue that will affect future generations, happen in other geographical locations, impact other social groups, or is uncertain. This sense of distance can reduce the urgency and importance individuals attach to climate change, impacting their motivation to engage in mitigative or adaptive behaviours. This is further explained by construal level theory that suggests that people mentally represent distant events in abstract terms while they perceive near events in concrete terms. Therefore, a distant abstract threat may never be as threatening as one that is immediate and concrete.  

In a large-scale study testing 11 popular interventions across 63 countries, reducing psychological distance was found to be the most effective at promoting belief in climate change. The main components of the intervention were:

• Sharing examples of recent natural disasters caused by climate change.
• Asking people to list aspects of their lives impacted by climate change (e.g. food, economy, health, etc.), followed by feedback regarding their response.
• People were asked to write about how climate change will affect them and their community.

Insights for communicating the significance of climate change

• Frame climate change as an immediate and present danger that threatens all localities on an individual personal level.
• Use messaging that leverages social norms and is framed in line with different social identities.
• Emphasise the co-benefits (e.g. health) of addressing climate change.
• Highlight scientific consensus (e.g. 97% of scientists believe that climate change is largely caused by humans) and try to find messengers that are highly respected within social groups.
• Myth-busting or psychological inoculations on Climate are not effective.

It's difficult to know which behaviour is impactful

Extensive research has been done to understand which behaviours are the most effective for reducing carbon emissions, however it is often a challenge for most people to know which actions have meaningful impact without needing to do extensive research. For example, the impact of switching to a sustainable diet was often underestimated while the impact of switching to LED lightbulbs was overestimated. Additionally, people struggle to understand the relative amount of energy consumed by different appliances and thus, how to achieve meaningful savings.  

Climate change mitigation behaviours are highly complex and technical, and so these misestimations of impact are to be expected. This is where government regulation can be combined with behavioural insights to better inform and guide people to adopting the most impactful actions. For example, to address the issue of people underestimating the carbon impact of certain foods, carbon labelling using accessible reference frames (e.g. light bulb minutes) was found to help shift food choices to more sustainable options.

Capitalising on the growing demand for more environmentally friendly products, companies can further complicate purchase decisions through the greenwashing of their own products, by either misleading consumers into thinking a product is green or is greener than it actually is, or charging a premium for green products, leading to a reduction in demand. Again, strong regulation around the labelling of products and an understanding of how people process this information is critical.  

Behavioural interventions to encourage pro-environmental behaviours

Beyond understanding how people think about climate change, behavioural science also looks at identifying ways in which we can change people's behaviours to help them reduce their impact on the environment. Research in this area (e.g. by the IPCC) highlights three main lifestyle areas where behavioural science interventions can be applied to: Energy, Diets and Transport.

Before exploring the research on interventions within specific lifestyle areas, there are several insights that are generally applicable.

1. Social comparison, financial incentives and structural changes are generally the most effective types of interventions.
2. Education was found to be the least effective.
3. People with higher income are less willing to engage in pro-environmental behaviours.
4. The effect sizes of interventions are generally always smaller when implemented in the real world at scale.
5. Climate anxiety is associated with more climate change mitigating behaviours.
6. Matching the type of intervention with the relevant behavioural determinant is important.
7. Combining different types of interventions can improve their efficacy and longevity. 

Examples of intervention types 

Diet

Most people underestimate the emissions associated with different types of food. Providing labels showing the emissions generated from the manufacturing of the products, presented using a familiar reference point, can shift purchase behaviour to lower emission products. 
Ultra-processed foods (UPFs) have a significantly high environmental footprint and so simply reducing the consumption of UPFs through nutrition programmes can have the double benefit of improving health while helping the environment. Plant based diets:
 

• When compared to health motives, pro-environmental attitudes were more strongly associated with motives to be vegetarian.  
• Amongst people with the intention to be vegetarian, it was found that they were more likely to eat meat during pleasurable or social situations (i.e. going out to eat with friends or for a specific craving, as opposed to practical routine meals). Therefore, targeting interventions in those moments are more critical to promoting consistent dietary behaviours.  
• The social identity associated with plant-based diets or dishes can discourage people from adopting a more sustainable diet:
  • Consumers prefer food products labelled as ‘healthy’ or ‘sustainable’ as opposed to ‘Vegan’ or ‘Plant-based’. Removing the vegetarian/plant-based symbol from menu items led to an increase in their sales.  
• Making plant-based options the default or the majority (with a 75/25 split of plant based vs meat option) in a menu can increase a shift to more plant-based choices. Alternatively, making vegetarian options the chef recommendation or described tastefully also leads to an increase in their purchases. 

Transport

• Attempts to nudge commuter behaviour using standard behavioural interventions, like non-cash incentives and personalised travel plans, have often failed to produce significant changes, highlighting the complexity of influencing commuting habits.  
• Personalized nudges, based on users' mobility patterns and personality profiles can encourage sustainable transportation habits. Such interventions can be incorporated into route planning apps for smartphones.
• Interventions focused on framing information about cars' fuel efficiency, emissions, and running costs clearly and saliently can influence consumers to make more sustainable transport choices.
• Choosing more sustainable transport choices also means encouraging people to purchase greener vehicles (when private transport is necessary). Here, using the right type of framing for messages to promote electric vehicles can shift preferences (e.g. electric motorcycles in Nepal).
• Providing feedback on driving behaviours, particularly in relation to fuel economy, has been shown to positively influence driver behaviour. Use of devices that offer real-time feedback on miles per gallon can lead to more fuel-efficient driving practices in some cases.  
• This was also effective for Aeroplane pilots. 
   

Energy

• Social comparison of a household's energy consumption to that of its neighbours is one of the most reliable findings in reducing household energy consumption
  • As the world starts to shift to using more renewable energy, power grids will have periods where there is too much energy and periods where there is less energy available. Combining this social comparison with reminders were effective at reducing consumption during times of peak load.
• In the context where utility companies are able to provide energy generated from renewable sources, 80% of business and residential customers opted for it when a renewable energy tariff was presented as the default option.
• In the context of LMICs where many households may still use solid biomass (e.g. coal) as sources of energy for cooking, product promotion combined with rebates were successful at encouraging the adoption of improved cook stoves. Additionally, social networks have a strong effect on the adoption of improved cook stoves (i.e. having neighbours that use improved cook stoves meant people were more likely to adopt it themselves).
  • For those unable to switch to cleaner forms of fuel, nudges can also be used to encourage households to use their wood burners in the least polluting way.
• Message framing (e.g. emphasising personal savings), were also effective at encouraging the installation of home solar panels.
  • This is especially important in LMICs where financial considerations are the main barrier to the adoption of solar panels 
     

Social Movements/Activism

One of the main areas where individuals can really make a difference to drive system level changes is through social movements or activism. It builds on the idea that people's roles in environmental protection extend beyond consumption habits to include political and community engagement. Behavioural principles can be applied to foster and guide social movements aimed at climate action. Understanding group dynamics, communication strategies, and motivational factors is key in mobilising collective efforts for environmental causes.

• For large scale and complex issues such as climate change, several factors can derail efforts, including:
  • Problem complexity can lead to apathy due to difficulty in understanding issues and seeing the impact of actions.
  • A variety of stakeholders with different interests and beliefs complicates achieving a unified focus.
  • The free-rider problem is more pronounced in larger movements where individual contributions are less visible, leading to fewer people taking responsibility for actively advancing the cause.
  • Cultural and social norms significantly influence collective action, with individualistic societies posing more challenges than those with communal traditions.
• To help facilitate social movements on large-scale issues, external support by a third-party, such as UNICEF, can be helpful.  
• Climate activists are driven by concerns about government inaction and environmental threats.  
  • Climate change distress or anxiety is associated with more activism. This may be triggered by a transformative moment such as seeing severe environmental degradation.  
  • Young people highly engaged in the climate activism identified with others protesting for climate protection, perceived similar behaviours among their friends, and expressed strong personal norms towards environmental activism, highlighting the importance of leveraging social norms for encouraging participation in social movements.  
  • The social identity of the movement is critical, as certain negative associations such as extremism can discourage participation.  
• A sense of solidarity is highly predictive of activism.
• Some factors that can promote a sense of solidarity include:
  • Use influential figures or role models to demonstrate solidarity in action.
  • Create opportunities for collective action by providing platforms for joint environmental initiatives.
  • Ensure transparency and commitment to shared values in communities by building trust.
  • Promote welfare-oriented values through education and community activities.
  • Recognise and respect everyone's equal value in sustainability discussions.
  • Encourage empathy towards others affected by environmental issues.
• Online activism is positively correlated with offline activism. Social media posts can mobilise others for offline protests, indicating a strong interconnection between online and offline domains. 
  • Online activism can also cultivate psychological preconditions like social identity formation, self-efficacy, and shared beliefs, which can embolden individuals to engage in offline protests. 

Policy promotion

• While individual behaviour change is important, it is sometimes more efficient or effective to drive change through taxes, laws, or regulation. These policy tools for climate mitigation are sometimes not looked upon favourably by the general population, leading to hesitancy by politicians to enact them. It is therefore important to understand how these policies can be sold to the public.
• Looking at the determinants of public opinion of climate change related policies, perceived fairness (i.e. policies targeted to the high emitters) and effectiveness (i.e. people’s belief that the policy will achieve the specific aim) were the most important.
• When it comes to encouraging support for climate related policies, providing explanations on how they work and highlighting who will benefit from them was found to be more important than educating people on the impact of climate change. Additionally, framing policies as positive opportunities rather than focusing on negative threats of climate change saw greater support for climate policy.  
• People may also look favourably upon climate mitigation policies when they feel like they lack the self-control to persevere on certain pro-environmental behaviours. For example, when people reported greater dissatisfaction with their failures to reduce meat consumption, they reported greater support for a carbon tax on meat products.