Scenarios for climate extremes and their socio-economic impacts

Organizers:Katja Frieler (PIK), Jana Sillmann (CICERO), Christian Otto (PIK), Matthias Kalkuhl (Mercator Institute), Reinhard Mechler (IIASA)


In the last decades, weather related extreme events have on average caused global annual economic damages of about 100 billion US$ (MunichRe, NatCatServiceTool). Temporally and spatially averaged numbers hide the potentially disruptive nature that particularly emerges from high-impact, low-probability outcomes, which can dominate estimates of total risk. Research is needed to develop scenarios, which combine insights from earth system modeling for understanding weather-related hazards and themodelling of bio-physical impacts (such as river floods, wildfires, crop failure) with knowledge on the risk drivers exposure and vulnerability of society and ecosystems (e.g., population shifts, infrastructure design, management practices). So far, comprehensive temporally and spatially explicit projections of aggregated damages, such as associated with compound events, have been hampered by the diversity of events (e.g. tropical cyclones, agricultural damages induced by droughts or heat waves, river or coastal flooding, and wildfires) that have only been individually addressed in different research disciplines. Recent interdisciplinary research efforts - fostered by large-scale model comparison exercises such as the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) and the emerging research field of disaster forensics - have opened up the possibility for event-based assessments of potential future damages and risks within the RCP-SSP framework.

With a focus on approaches that seek to align retrospective forensic methods with forward-looking scenario analysis this session addresses a range of topics along the chain from i) plausibility and uncertainties in climate (impact) model simulations (e.g. related to land-atmosphere interactions, model resolution etc.), to ii)  projections of direct damages aggregated across different types of weather related extreme events, and ii) macroeconomic modelling approaches that allow for the translation of direct damages to macroeconomic risks.

This will include aspects of exposure and vulnerability within an RCP-SSP framework but also storyline approaches for scenarios of individual compound events that go beyond a purely probabilistic approach.