Scientific publications

Energy -sector decarbonisation requires large -scale investment in low -carbon technologies, yet only a limited share flows to low - and middle -income countries, partly due to higher financing costs and perceived risks. Most modelling exercises do not fully account for how the cost of capital may vary across regions and technologies, potentially influencing policy insights. We examine how plausible, expert -informed long -term trends in de -risking clean energy and increasing risks for fossil fuels could shape decarbonisation pathways, using an empirical dataset differentiated by country and technology. We also evaluate a “corrective justice” policy that taxes corporate windfall profits and redistributes revenues to support low -carbon investments in higher -risk regions. Results suggest that incorporating differentiated cost -of-capital trajectories may improve mitigation outcomes and help narrow the gap between current commitments and long -term climate targets, while indicating potential underestimation of risks associated with bioenergy -based negative emissions technologies in mitigation scenarios for high -income nations.

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.

In recent years, countries have significantly expanded the use of unilateral trade-related climate measures to address global climate change, including greenhouse gas emissions embodied in internationally traded goods. This trend reflects both the persistence of carbon leakage risks in a world of nationally determined climate action and a broader shift toward achieving extraterritorial policy influence through conditional market access and soft regulatory power. The paper reviews evidence of emissions related to international trade and examines unilateral measures that states have deployed in the context of climate change mitigation efforts. These include transparency tools such as emissions reporting requirements; product carbon requirements that restrict market access for carbon intensive goods; border carbon adjustments; green subsidies and public procurement; and supply chain due diligence obligations. Together, these trends illustrate how unilateral traderelated climate measures can complement multilateral processes by reducing global emissions while reshaping incentives across international supply chains, but also entail risks of protectionism and trade distortions.

The European Union’s (EU) climate strategy, anchored in the European Green Deal, the Fit-for-55 package, and the updated National Energy and Climate Plans (NECPs), requires a rapid transformation of the energy system to meet the legally binding target of net-zero greenhouse gas emissions by 2050 and a 55% reduction by 2030 relative to 1990 levels. Yet, how national plans align with EU-wide ambition, alongside the implications for investment, infrastructure, and power-system operation, remain insufficiently assessed. We address this gap by linking an EU-specific implementation of a prominent integrated assessment model with Member State-level disaggregation (GCAM-Europe) with a higher-resolution European electricity system model (EXPANSE). This modelling framework captures national heterogeneity, sectoral detail, and spatiotemporal variability in electricity demand, renewable supply, and storage, enabling the assessment of grid investments and infrastructure. We analyse four scenarios representing EU-wide (Fit-for-55) or national (NECP) targets, implemented through explicit policies (POLICY) or cost-optimal carbon caps (COST_OPTIMAL). 

As global climate policy intensifies, emissions-intensive industries like steel face a critical challenge: how to balance deep decarbonization with economic competitiveness. Our study uses an innovative, modified integrated assessment model to explore how carbon border adjustment mechanisms (CBAMs) can reduce carbon leakage, support the transition to low-carbon technologies, and shape global steel trade dynamics under ambitious climate targets. In contrast to existing literature, it explores the net effect of CBAM in a context where steel producers are exempted from carbon pricing otherwise, touching upon the policy reality in which decarbonisation occurs within the context of national industrial policy.

Key insights include:
• CBAMs can meaningfully reduce emissions leakage when paired with pricing of direct steel emissions.
• Policy design matters — nuances like free emission allowances, export rebates, and technology subsidies significantly affect competitiveness, trade flows, and emission outcomes.
• Our findings provide data-driven guidance for policymakers and industry stakeholders navigating the trade-off between decarbonization and industrial strategy.

As nations and regions consider carbon pricing tools to meet their climate commitments, this work highlights the complex interplay between climate policy, global trade, and industrial transformation.

Socio-technical transitions literature has so far engaged very little with the question of how international institutions could foster transitions. Conversely, international climate policy literature shows gaps in engaging with transformational change. To address these gaps, this article analyses the potential of the first Global Stocktake (GST) under the Paris Agreement to foster transitions. The article first develops a novel conceptual framework for how international institutions can promote transitions. On this basis, the article synthesises recommendations for the GST outcome from literature and the GST process and compares them with the actual outcome. The article finds that the GST sent important signals and fostered knowledge and learning on key aspects of low-emission transitions. However, it mostly focused on energy systems and failed to establish mechanisms and resources to promote actual implementation.