The challenge with climate-energy-economy models in constructing fair and equitable climate futures

Climate change and policy are unevenly experienced across nations, social groups, households, sectors, and generations. Understanding how benefits and burdens of climate action can be equitably shared is therefore critical. While the cornerstone concept of ‘common but differentiated responsibilities and respective capabilities’ is broadly accepted, the absence of consensus on equitable effort-sharing principles presents a challenge that permeates science underpinning climate policy. Climate-energy-economy models exhibit considerable conceptual, structural, and technical limitations in constructing equitable climate futures: they aggregate diverse Global South countries into homogeneous regions, fail to capture critical elements of international climate finance, and tend to produce one-size-fits-all strategies with limited consideration of local contexts. Model-based studies, additionally, have been argued to reflect Global North narratives in international scenario ensembles, assume persisting inequalities between the Global North and the Global South in the future, obscure ethical or normative choices behind operationalised principles of justice, and fail to systematically include stakeholders and scientists from the Global South. Here, we explore how modelling science can be more inclusive and effective in recognising these issues and co-constructing just climate futures. While acknowledging the inherent limitations of any modelling exercise, we argue that progress depends on several key actions, including meaningfully collaborating with stakeholders and scientists from other disciplines and critically from hitherto underrepresented and underfunded regions, incorporating wider policy priorities beyond mitigation, improving data and modelling capabilities to better represent the varied conditions of different communities, and integrating elements, policies, and governance structures that are indispensable to representing climate finance considerations.