The main task of the Intergovernmental Panel on Climate Change (IPCC) is to provide comprehensive assessments of climate science. However, there are accusations of bias toward certain research fields based on limited empirical evidence. By analyzing the evidence base of Working Group 3 (WG3) reports, we show that integrated assessment modeling (IAM) research was influential in all six assessments, and overrepresented in the Summary for Policymakers (SPM). Further, we show that a small number of men working in Western Europe and the USA dominate IAM research. Thus, global climate negotiations and science may have historically prioritized mitigation solutions suggested by an unrepresentative scientific sample and missed solutions from other perspectives like those of females and non-Western cultures. However, we also show that IAM research influence decreased in AR6, implying a leveling playing field between research fields. But more effort is needed to ensure a comprehensive assessment.

Energy models are used to study emissions mitigation pathways, such as those compatible with the Paris Agreement goals. These models vary in structure, objectives, parameterization and level of detail, yielding differences in the computed energy and climate policy scenarios. To study model differences, diagnostic indicators are common practice in many academic fields, for example, in the physical climate sciences. However, they have not yet been applied systematically in mitigation literature, beyond addressing individual model dimensions. Here we address this gap by quantifying energy model typology along five dimensions: responsiveness, mitigation strategies, energy supply, energy demand and mitigation costs and effort, each expressed through several diagnostic indicators. The framework is applied to a diagnostic experiment with eight energy models in which we explore ten scenarios focusing on Europe. Comparing indicators to the ensemble yields comprehensive ‘energy model fingerprints’, which describe systematic model behaviour and contextualize model differences for future multi-model comparison studies.

The impact of waste policies and measures from National Determined Contributions (NDCs) on the Sustainable Development Goals (SDGs) is unexamined and creates conditions for policy conflict and incoherence. This participatory case study of North Macedonia quantifies synergies and trade-offs. Our results show twelve times more synergies than trade-offs. The most important synergies concern SDG 8: Decent work and economic growth (score: 10) and SDG 3: Good health and well-being (score: 5) since formalizing the recycling sector is expected to create jobs, economic productivity is expected to improve as a result of increased resource efficiency in industry, and declining pollution is expected to increase health through adequate waste management in landfills. On the other hand, the most important trade-off pertains to SDG 1: No poverty (score: −3) because the incomes of informal workers are expected to decrease, affecting financially vulnerable families. In conclusion, despite being the least emitting sector globally, the waste sector is a promising avenue for mitigating climate change because of its synergistic effects with the SDGs. Circular economy policies in line with the 3Rs: reduce, reuse and recycle hold the most potential for synergies in developing countries. This case study generated momentum for policy implementation by highlighting policy synergies and ideas for the next revision of the NDC. Central to this was the process of fostering dialogue and learning among otherwise siloed policy actors.