Climate change is unequivocally linked to human activity, leading to unprecedented warming of the planet1. Yet, despite the urgent need to reduce greenhouse gases (GHGs) emissions, technological and governmental solutions are not being implemented fast enough to reach the desired goals. Individual behavior change would make an important contribution to reducing GHGs emissions without the need to adopt new technology2. Nevertheless, available behavioral interventions commonly focus only on low-impact behaviors, such as recycling or water management, and report small effects (d = 0.093) that rarely persist beyond the intervention context3. A more consequential, but perhaps more challenging, the target would be to alter habits around food choice. Today’s food supply chain contributes to 26% of the current GHGs emissions, with the highest emissions linked to beef production3, and adopting more plant-based diets could reduce GHGs emissions by 29–70%4,5. In the context of such figures, identifying effective new interventions that would facilitate a switch to more sustainable diets would seem a priority. Engagement in such consequential pro-environmental behaviors (PEBs) typically requires the suppression of self-interest, or deeply ingrained habits, in favor of long-term societal consequences. To create such change, more sophisticated and emotionally-rich interventions that target specific psychological barriers are necessary.
Emerging evidence suggests that immersive Virtual Reality (VR) can be a powerful tool to promote pro-environmental behavior6. For example, VR-mediated natural experiences have been shown to increase connectedness to nature7,8 and to promote pro-environmental behavior as effectively as a real-life nature hiking experience9. Immersive VR enables the creation of realistic and embodied situations which provide rich sensory input10, ensuring that virtual experiences nonetheless feel proximal to the individual11. According to some12, 13, the experience of proximity to the self is central to action against climate change – the consequences of which often remain too abstract, or too spatially and temporally distant, to trigger risk perception and readiness to act. Nevertheless, low-risk perception is not the only barrier to action: heightening risk preceiptions can also trigger defensiveness in the face of threat12–14. One important determinant of whether people respond adaptively or maladaptively to perceived risks and feelings of threat is the efficacy they perceive in taking action. Consistent with this, both perceived self-efficacy (the belief in the personal capacity to execute desired actions) and response-efficacy (the belief that the actions will contribute to the solution) have also been identified as important drivers of pro-environmental behavior 15. Interventions that simultaneously induce risk perceptions and build up efficacy beliefs should be maximally effective, both in general16 and in the specific context of attempts to promote climate-friendly diets17.
VR has a number of features that dovetail nicely with the identified psychological features of climate action. A recent theory of immersive learning18 describes how the dual affordances of presence (the feeling of being physically and socially present in the virtual environment19), and agency (the sense of being in control of one’s actions in the virtual environment20), make VR a potentially effective tool for learning and behavioral change. Both presence and agency are especially high in interactive simulations experienced through head-mounted displays (HMDs)21 and can lead to enhanced motivation, self-efficacy, and response efficacy (factors crucial for eliciting behavioral change18,22) when VR simulations are developed according to instructional design principles23,18,20,24. Consistent with this model, recent research shows that VR provides mastery experiences that positively impact self-efficacy and response-efficacy beliefs22,25, and that VR can help individuals to visualize the impact of their behavior on the natural environment26.
Despite the emerging evidence that VR can promote pro-environmental intentions and, in some cases, behavior, there is only limited evidence about the ability to facilitate the switch to plant-based diets26,27. One very recent study by Meijers et al.26 reports the influence of climate impact messages on behavior in a virtual supermarket, and the indirect effect of these on self-reported consumer decision-making one week after the experiment. Although this study identified personal response efficacy as an important mechanism for change in response to VR, immediate behavior change was not separate from the manipulation of impact messages, and delayed behavior change was self-report. As such, consequences for reductions in individual carbon footprints are unknown. In another recent study, Fonseca and Kraus27 reported preliminary evidence that VR can be a suitable tool for promoting change in sustainable dietary behavior. According to their results, an immersive VR video resulted in a larger preference for vegetarian meals immediately after the intervention compared to a control group, and this was also reflected in spontaneous choices of vegetarian over non-vegetarian snacks after the simulation. However, the sample size for this study was very small (n = 36 for 3 conditions) and the behavioral consequence of VR was not distinguishable from less immersive presentations (i.e., viewing the same video on a tablet).
Here we tested the behavioral consequences of a novel VR intervention designed to promote self-efficacy and response-efficacy beliefs. The intervention was designed using instructional design principles (e.g., embodiment, personalization, and modality principle) to facilitate the impact of agency and presence on the behavioral outcome18,23. Furthermore, similar to previous studies, we aimed to increase response-efficacy by visualizing the impact of individual behavior26,28,29, in our case the impact of food choices on the natural environment. As previous VR research shows the importance of gradual changes30 and vivid messages31 for behavioral change, the impact of current food choices on the environment is visualized continually by transporting participants 30 years into the future. Furthermore, the educational part of the intervention provided users with explicit instruction for how to behave environmentally as some research highlights how the lack of specific guidelines can limit transfer to real-life behavior32 and actual impact in terms of carbon emissions26. Finally, to build self-efficacy using mastery experience33, users were allowed to change their behavior and were given customized feedback about their choices through the gradual restoration of nature.
In this study, we compare the effectiveness of this VR intervention against a passive control condition. As stated in the preregistration, we hypothesized that:
H1: The VR intervention will lead to a larger decrease in the carbon footprint compared to the control group.
H2A-E: The VR intervention will impact all predictors (intentions, self-efficacy, response-efficacy, knowledge, psychological distance) of pro-environmental behavior to a larger extent compared to the control group.
H3A-D: In the follow-up, the IVR intervention will impact all predictors (self-efficacy, response-efficacy, knowledge, psychological distance) of pro-environmental behavior to a larger extent compared to the control group.
Furthermore, we explored if the VR treatment can be enhanced by other interventions that have been tested within environmental research: normative feedback and geographical location (distant vs. proximal). Previous research shows that social norms, (alongside self-efficacy, response efficacy, and negative emotions), play a crucial role in regulating climate-related behavior15. Properly administered normative feedback (i.e., about one’s performance relative to significant others) has been demonstrated to be useful for motivating behavior change34, and for supporting individual feelings of self-efficacy35, across a variety of domains, including the environment. Furthermore, the perception that climate change is distant from the individual – that is, happening to people who are far away from both in time and space - is often argued to be the leading barrier of climate change inaction36,37. Yet, despite this common assumption research manipulating psychological distance has produced mixed findings 38–40, suggesting that this approach can only have limited utility within interventions designed to encourage climate-related action. Because immersive VR allows realistic visualization of climate change on nature at different geographical and temporal scales, it seems to be a perfect tool for further investigating the role of psychological distance in motivating action. Supportive of this idea a previous study conducted using non-immersive VR showed that navigating a polluted river framed as geographically closer resulted in higher risk perception, which, together with self-efficacy, predicted self-reported pro-environmental behavior41. Building on these ideas, our study further explored the role of both normative feedback and geographical distance in shaping the effects of the VR intervention.