Global South circularity for climate change mitigation: insights into Integrated Assessment Modelling

As global wealth and population have grown, the world’s demand for materials has tripled since 1970, raising greenhouse gas (GHG) emissions from material production, extraction and use due to their intensive energy requirements (United Nations Environment Programme, 2024). The circular economy (CE) is considered a novel approach to production and consumption systems that emphasises cyclical, renewable arrangements that extend the life and usefulness of materials and resources (Korhonen et al., 2018), drawing extensively from work undertaken in the Industrial Ecology (IE) field. The transition to a CE is anticipated to have a profound impact on GHG emissions (Khalifa et al., 2022) across various sectors (Cantzler et al., 2020). Given this mitigation potential, calls have been made for Integrated Assessment Models (IAMs) to better integrate modelling of material stocks and flows (Pauliuk et al., 2017), enabling more comprehensive representation of material efficiency and CE strategies (Ünlü et al., 2024). 

However, both IAMs and CE scholars have faced significant criticism for their inadequate consideration of the so-called “Global South”. IAMs have been shown: to be insensitive to developmental needs (van Ruijven et al., 2008); to poorly interpret low-income economic and energy dynamics (Lucas et al., 2015); and to underrepresent Global South participants in scenario and model development (Miguel et al., 2019). Meanwhile, the Global South has been relatively obscured from dominant narratives of CE predicated on corporate leadership, technocratic solutions (Kirchherr et al., 2017) and decoupling growth from environmental impacts (Ghisellini et al., 2016). Global South circularity is shown to be more often necessity- and value-driven, building on bottom-up adaptive community and informal economic practices that respond to limited services and material scarcity (Korsunova et al., 2022; Schröder et al., 2019). Critically, there is now an opportunity within the IAM community to respond to these differing manifestations of circularity as model development is underway, widening the relevance of IAMs to academics and decision-makers operating in the Global South.

In this paper, we aim to understand how process-based IAMs can better integrate the unique contexts and processes of the Global South while developing and extending modelling frameworks to better assess material cycles and CE strategies for climate change mitigation. First, we review the literature on Global South CE for climate change mitigation from which we derive five major modelling challenges for Global South circularity in IAMs, namely scalability, informality, applicability, developmental trade-offs and measurability. Then, we conduct interviews with IAM developers working on CE-related or Global South-based modelling to understand (1) the major factors involved in integrating material stocks and flows into process-based IAMs and (2) how these factors interact with the five aforementioned major challenges for modelling Global South circularity. We combine the insights from both the literature review and expert interviews to suggest improvements for modelling the Global South in IAM-material models from both theoretical and technical perspectives. Overall, our paper contributes actionable recommendations for modellers seeking to redress concerns around the equity and representativeness of climate mitigation models and scenarios and their applicability to diverse socioeconomic contexts.