Cimate Change-Related Temperature Increases and Associated Health Risks for Cities in the Shue Database

Abstract

Introduction: Climate change and increasing urbanization are expected to increase the risk of temperature-related impacts on health for many of the world’s cities. We explored the nature of the likely temperature changes by 2050 under climate change in relation to city characteristics and health vulnerability. Methods: The SHUE database contains 309 randomly-selected global cities, stratified by population, wealth, and climate region, with data on city characteristics compiled from existing sources. Current and future (2050) monthly temperature distributions for each city were estimated from downscaled results of ensembles of 11 climate model runs under Representative Concentration Pathway 6.0. For each city’s 2050 climate, the city with the most similar current climate was identified (its ‘climate analogue’). Where available, city-specific temperature-mortality functions were used to estimate changes in health burdens. Results: Temperature changes by 2050 varied appreciably from city to city and model to model (median +1.9 °C, range -3.5 to +7.3 °C) but were generally largest in summer months, at northern latitudes and in wealthier cities, with the greatest increases in Europe and North America. One of the largest estimates of change is for Sofia (median +3.4 °C) which would translate to a 9.8% increase in mortality in the hottest month, assuming no adaptation and linear extrapolation of risk beyond the upper end of the current temperature distribution. For most cities and climate models, annual temperature profiles in 2050 remain similar to the present day profiles of other cities in the same climatic zone. Conclusions: Insights into future heat-related health burdens may be gained by understanding how a city’s 2050 temperature distribution is approximated by the present day climate patterns of other cities. However, the scope for studying climate analogues beyond 2050 is reduced due to the much greater anticipated increases in temperatures.