Climate change is one of the greatest challenges of our time. At the recent 28th Conference of the Parties of the UNFCCC (COP28), a commitment was made to transition from fossil fuels to renewable energy sources and improve energy efficiency in a just and equitable way aiming for net zero by 2050. Despite debates on the progress and existing gaps, the COP28 outcomes signal the start of the decline of the fossil fuel era.

However, Earth has already experienced a 1°C increase in average temperature, leading to alarming changes. Increased frequency and intensity of extreme weather events, such as the ongoing drought in the Horn of Africa, heatwaves in Southern Europe and the devastating 2023 wildfires in Hawaii, highlight the urgent need for global action towards climate-resilient development pathways.

Effective adaptation requires a rigorous and shared understanding of climate risks and vulnerability. Climate risk assessments are emerging as a key approach to support local adaptation initiatives. Recognizing the potential of this approach, the project Unpacking Climate Impact Chains (UNCHAIN) explored ways to enhance these assessments, laying the groundwork for more effective EU decision-making and adaptation and offering insights for the global research and policy community. The project focused on the impact chain approach, which is structured around the Intergovernmental Panel on Climate Change (IPCC) fifth assessment report’s conceptualization of risk  (Zebisch et al., 2021).

Through five methodological innovations to the approach tested in 11 European case studies, UNCHAIN involved diverse stakeholders in adaptation across various regions, sectors and decision contexts. SEI research in this article collection highlights advancements in social vulnerability, knowledge co-production processes and transboundary climate risks, providing valuable insights for risk-informed, actionable, just and equitable adaptation action.

Addressing transboundary climate risks

To effectively manage the full spectrum of societal risks in a globalized world, policymakers must consider transboundary climate risks that cascade across political jurisdictions, supply chains and capital flows. Managing these risks requires strong international partnerships to foster effective and systemic adaptation decisions and actions. Overlooking transboundary climate risks can lead to underestimating risk exposure, omitting key risks and vulnerable actors, and failing to motivate necessary adaptation investments and cooperation.

Collaborating with stakeholders to build knowledge

UNCHAIN case studies demonstrate that the impact chain approach effectively structures stakeholder collaboration in co-producing climate risk assessments. These collaborative, iterative processes create new platforms for dialogue and knowledge exchange and can empower stakeholders and citizens to engage in equitable and transformative adaptation processes with policymakers.

However, these processes require careful consideration of financial and human resources, expertise and facilitation to balance power dynamics and ensure meaningful participation. Challenges include the absence of iterative learning and the need for flexibility to suit regional and local contexts. Overcoming these obstacles involves focusing on the process rather than outcomes, setting joint learning objectives and supporting iterative learning through the implementation of monitoring, evaluation and learning frameworks. Properly designed and facilitated, stakeholder collaborations can bridge the science-policy gap, aligning user needs with climate information and producing actionable knowledge for adaptation.

Prompt, equitable and just adaptation

For systemic adaptation, policymakers must consider technical, climatic and social factors, including the varying adaptive capacities of regions and citizens. Social vulnerability assessments, enriched by the impact chain approach, can identify social injustices, locate vulnerable communities and avoid exacerbating social vulnerabilities. These assessments should inform targeted policies and interventions, enhancing resilience among vulnerable populations. Policymakers can thus foster just and equitable adaptation, equipping all citizens, regardless of socio-economic status, to manage the impacts of climate change.