PRISMA hosted a research webinar on representing lifestyles in integrated assessment models (IAMs). Nicole van den Berg from Utrecht University presented a set of scenarios, called SLIM – Sustainable Living in Models – which focuses on two critical uncertainties: more individualistic or collectivist values; and more centralised or distributed support for sustainable lifestyles. Four scenarios emerged from the analysis, leading to unique, sustainable futures and just transitions. Firstly, the qualitative SLIM scenario narratives illustrate how structural support and value systems shape lifestyles differently and change dynamically in response to enablers and societal shifts. The scenario narratives identify the extent and speed of lifestyle changes for modelling the SLIM scenarios, with regional differentiation and equity considerations. The emission pathways show the implications of the SLIM scenarios towards sustainable living and highlight that lifestyle changes contribute substantially to climate change mitigation, mostly with larger systems change, to achieve transformative outcomes. More specifically, lifestyle changes could reduce passenger transport and residential emissions by about 39% for Global North regions and 27% for Global South regions in 2050 compared to a scenario based on current trends. These scenarios can help guide strategic dialogue and global climate change mitigation decisions and actions by considering lifestyle change in the context of larger systems change. In conclusion of her research which was part of her PhD thesis, Nicole proposed the development of a lifestyle module in IMAGE, explicitly modelling the behavioural actions in a dedicated place within the model. 

In the discussion, Hazel Pettifor (University of Oxford) and Alessio Mastrucci (IIASA) who acted as discussants in the webinar, highlighted the empirically-based nature of the research that, in an expert-driven process, developed rich lifestyle narratives. Turning the narratives into model assumptions to complement them by quantitative emissions pathways, either by using an endogenous or exogenous mechanism in IAMs remains a challenge. Endogenous approaches have the advantage of being able to capture feedback effects between the evolution of lifestyles and development of infrastructure (e.g., public transport infrastructure fostering lifestyle change with mobility implications). Exogenous approaches do not capture these feedbacks but allow to represent a much broader range of effects of lifestyle changes. The research underlines that representing lifestyle changes and their heterogeneity is important. It illustrates the significant potential of lifestyle change to contribute to emission reductions. Therefore, the development of a formal lifestyle module to be used in IAMs is an important to formalize the representation of lifestyles by taking a structured approach.

In the following open discussion, questions about the representation of gender differences in lifestyles in Nicole’s work on the SLIM scenarios and the inclusion of feedbacks from climate change mitigation policies were raised. Regarding the gender dimension, some population heterogeneity is represented in the IMAGE model which ended up being an important aspect of the development of lifestyle quantifications, but the gender dimension has thus far not been explored. However, there is interest and ambition to moving into this direction which would likely result in the addition of gender aspects to the narratives. This could be an opportunity for collaboration. The feedback of mitigation action on lifestyles has not yet been explored in the SLIM scenarios. Also, the interaction of lifestyle analysis with the Shared Socio-economic Pathways (SSPs) has not been analyzed in the SLIM scenarios, but both would be very interesting research directions.  

Finally, based on the research by Nicole and others in the PRISMA project, the scope of developing a “community lifestyle tool” was discussed. While it is challenging to identify entry points in individual IAMs, the development of a separate more generic community part of a lifestyle tool could be taken which then need some customization to link it into specific models. Some efforts into this direction include the development of the LIFE model (Pettifor et al. 2023) that is currently being linked to three different IAMs.

About the speaker:

Nicole van den Berg (https://www.uu.nl/staff/NJvandenBerg/) is a postdoctoral researcher at Utrecht University (UU), with a focus on behaviour change in models. In her PhD research, also at UU, she explored how to effectively incorporate lifestyle changes into Integrated Assessment Models (IAMs). She has a master’s degree in Industrial Ecology from Delft University of Technology and Leiden University (NL) and a bachelor’s degree in Liberal Arts & Sciences (majors in geography and environmental sciences) from University College Utrecht (NL). Her interests include interdisciplinary research and the dynamic interactions between energy, economic systems, and climate policy. 

Agenda:

• Welcome (Volker Krey, IIASA, 5 mins)
• Presentation “Sustainable Living in Systems Change: Modelling Lifestyle Change in IMAGE” (Nicole van den Berg, UU, 25 mins)
• Discussants (Hazel Pettifor, UOX, Alessio Mastrucci, IIASA, 5-10 mins)
• Open Discussion (all, 20-25 mins)

This meeting was part of a project that has received funding from the European Union’s Horizon Europe programme under grant agreement No 101081604 – PRISMA.

Views and opinions expressed are however those of the speaker(s) only and do not necessarily reflect those of the European Union or the European Climate, Infrastructure and Environment Executive Agency (CINEA). Neither the European Union nor the granting authority can be held responsible for them.

By IIASA