Abstract ID: 3.12393 | Accepted as Talk | Talk/Oral | TBA | TBA

As human-induced global warming continues, the probability of climate-related extreme events is rising. The simultaneous occurrence of various extreme events and resulting impact cascades can present substantial risks to mountain communities and ecosystems.
Analyses of climate-related extreme events traditionally follow a ‘top-down’ method, where event magnitudes and return periods from climate model simulations are used in impact models to characterize potential effects on the affected systems. However, such approaches face limitations due to significant uncertainties in climate models when simulating compound and unprecedented extremes, and these uncertainties then propagate through the further impact analysis. Additionally, many systems lack impact models that can integrate climate model outputs and account for various process cascades and interconnections. These constraints hinder the effectiveness of top-down approaches for decision-making and adaptation planning.
Here we present results from bottom-up and decision-centric case studies that approach the problem starting from the impact and the effect of policy leavers on such impacts (i.e. adaptation). We do this by defining thresholds and operational ranges for system robustness and explore the landscape of decision making within such boundaries. Exploratory modelling, dynamic programming and semi-quantitative expert elicitation were used to characterize potential impacts and their cascading effects as a function of climate and socio-economic scenarios, climate models, extreme events and adaptation options. The case studies analysed the impact of compound heat and drought in protective forests, debris-flow and flood risk for an alpine community, warming thresholds for Swiss ski resorts and water management in a data scarce mountain region. Results provide a novel perspective contributing to the design and implemention of robust adaptation measures.
We compare and discuss the strengths and limitations of the different approaches and discuss future directions and priorities for working towards integrative analysis of cascading impacts and to allow successful adaptation planning.