A Framework for Mapping Global Climate Multi-Hazard Risks under Future Climate Scenarios

Climate change presents escalating challenges, impacting people, the environment, and the economy. Climate-related hazards are expected to intensify their effects in the future, making it essential to build disaster risk reduction capacity. To address these challenges, international financial institutions and governments worldwide require accurate, up-to-date, and comprehensive information to understand the spatiotemporal distribution of risk, identify risk hotspots, and support the preparation of adaptation strategies to enable the prioritization and effectiveness of adaptation investments. Within the ESA-funded GDA-Climate Resilience project, a comprehensive framework has been developed to assess spatially explicit relative risks under current and future climate scenarios on a global scale, serving as a basis for a decision support tool aimed at implementing climate risk services. This framework aims to provide decision-makers with critical insights into relative risk variations under future climate projections, considering  key hazards such as droughts, warm spells, and floods and focusing on receptors such as agriculture and population. This innovative, pixel-level relative risk assessment approach utilizes open-source global datasets to evaluate future relative risk levels from multiple climate hazards. It encompasses three SSP-RCP scenarios—SSP1-2.6, SSP2-4.5, and SSP3-7.0—over the period from 2020 to 2099, with 20-year time steps, using 1995–2014 as the reference baseline. The current implementation examines drought-agriculture, warm spell-population and flood-population hazard/receptor combinations, adopting the IPCC’s framework for hazard, exposure, and vulnerability dimensions in defining risk. Risk estimation is provided both as a 0-to-1 index, enabling spatial and temporal global comparability, and as a risk variation index, informing decision-makers about areas where the risk is increasing most rapidly. Additionally, the framework explores multi-hazard risk, enabling the analysis of combined impacts from various climate hazards on different receptors, such as populations and agricultural systems. Our initial findings reveal a significant increase in relative risk for both droughts and warm spells over time compared to baseline levels. Several high-risk hotspots have been identified, as well as areas with shifting future risk profiles from individual hazards both globally and within individual countries, under specific time steps and climate scenarios. Further research may focus on the exploration of emerging risks arising from multi-hazard interactions. In general, this approach offers valuable insights to guide decision makers in fostering adaptation strategies and investments, and provides a foundational step for a future, spatially explicit and comprehensive global risk assessment platform.