Rapid changes in return periods of heat-related mortality extremes
- 1Institute for Environmental Decisions, ETH Zurich, Zurich, Switzerland
- 2Federal Office of Meteorology and Climatology MeteoSwiss, Zurich-Airport, Switzerland
- 3Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
- 4Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- 5Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
- 6Department of Public Health, Environments and Society, London School of Hygiene & Tropical Medicine, London, UK
The risk of extreme heat mortality is ever increasing with the rapidly changing climate. With the collision of several mega-trends – aging societies, urbanization, inequality – the need for a comprehensive heat mortality risk analysis is growing. Here, we present a probabilistic analysis of the impact of extreme heat on city-scale mortality, demonstrated for more than 750 locations around the world. First results show that heat-related excess mortality of a 100-year summer in the climate of 2000 must be expected roughly every ten to twenty years in today’s climate for most locations.
We produce the probabilistic risk assessment for heat mortality by building on the open-source natural catastrophe risk platform CLIMADA (CLIMate ADAptation). We combine state-of-the-art epidemiological time series analysis methods with single model initial condition large ensemble (SMILE) climate model output. The epidemiological analysis relies on quasi-Poisson regression time series analyses and requires daily city-level mortality data which we have for more than 750 locations through the MCC (Multi-Country Multi-City) Collaborative Research Network database. This analysis results in city-specific risk of exceedance mortality as a function of temperature. The SMILE approach takes a climate model and runs it multiple times with perturbed initial conditions but using the same climate scenario. It thus indicates multiple physically consistent and plausible pathways of the climate which can be used for a probabilistic risk assessment. This allows estimation of tail-risks and quantification of return-period-based mortality impacts. We used SMILE output of seven different climate models, totaling 270 model runs, to estimate impacts and uncertainties of tail risks.
Communicating risk using (shifts in) return periods is helpful to start dialogues with government authorities, city planners and decision makers, as such metrics are commonly used to prepare for natural catastrophes
How to cite: Lüthi, S., Fairless, C., Fischer, E. M., Vicedo-Cabrera, A. M., and Bresch, D. N.: Rapid changes in return periods of heat-related mortality extremes, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5183, https://doi.org/10.5194/egusphere-egu22-5183, 2022.
