UNCHAIN – Unpacking climate impact chains

The UNCHAIN project utilizes an impact chain method to improve climate change risk assessments and adaptation actions. In a case study in Halmstad, Sweden, researchers adapted this model to explore how multiple hydrometeorological hazards interact with pre-existing vulnerabilities to create cascading disruptions across critical infrastructures and vital societal functions, potentially generating new vulnerable social groups. The process emphasized the co-production of knowledge, integrating stakeholder expertise from sectors such as water services, urban planning, and risk management through a participatory, iterative approach based on five selected modules of the impact chain framework.

• The UNCHAIN approach employs an impact chain method based on the concepts of hazard, exposure, and vulnerability, structured around eight modules to provide guidance for implementing risk assessments.
• In Halmstad, Sweden, the research focused on how multiple hydrometeorological hazards—such as sea level rise, storm surges, and flooding—can occur simultaneously or 'cascadingly', causing disruptions to critical infrastructures and vital societal functions.
• The project adapted the standard impact chain model to better capture multidimensional and situational factors, proposing a flow where a climate signal triggers multiple hazards that interact with pre-existing vulnerabilities to create cascading effects and 'emerging social vulnerability'.
• The Halmstad case study utilized a co-production of knowledge approach, combining the impact chain model with the Tandem framework to foster iterative collaboration between researchers and municipality stakeholders across disciplines.
• Due to a lack of historical data on hazardous events in Sweden, the project used a scenario-based approach where stakeholders co-designed scenarios based on local knowledge and the Halmstad Municipality adaptation plan.
• The research process in Halmstad implemented five of the eight impact chain modules, resulting in outputs such as a social vulnerability index and spatial vulnerability maps based on open data from Statistics Sweden and Delmos.

APA

André, K., Englund, M., & Swartling, Å. G. (2022). UNCHAIN – Unpacking climate impact chains. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2022/10/impact-chain-model-sei2022.041.pdf

Chicago

André, Karin, Mathilda Englund, and Åsa Gerger Swartling. UNCHAIN – Unpacking climate impact chains. Stockholm Environment Institute, 2022. https://www.sei.org/wp-content/uploads/2022/10/impact-chain-model-sei2022.041.pdf.

Wikipedia

{{cite report |last1=André |first1=Karin |last2=Englund |first2=Mathilda |last3=Swartling |first3=Åsa Gerger |title=UNCHAIN – Unpacking climate impact chains |publisher=Stockholm Environment Institute |date=October 2022 |url=https://www.sei.org/wp-content/uploads/2022/10/impact-chain-model-sei2022.041.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{andr2022unchain, author = {André, Karin and Englund, Mathilda and Swartling, Åsa Gerger}, title = {{UNCHAIN – Unpacking climate impact chains}}, institution = {Stockholm Environment Institute}, year = {2022}, month = oct, url = {https://www.sei.org/wp-content/uploads/2022/10/impact-chain-model-sei2022.041.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }