Projections of temperature-attributable premature deaths in 209 U.S. cities using a cluster-based Poisson approach

Abstract

BackgroundA warming climate will affect future temperature-attributable premature deaths. This analysis is the first to project these deaths at a near national scale for the United States using city and month-specific temperature-mortality relationships.MethodsWe used Poisson regressions to model temperature-attributable premature mortality as a function of daily average temperature in 209 U.S. cities by month. We used climate data to group cities into clusters and applied an Empirical Bayes adjustment to improve model stability and calculate cluster-based month-specific temperature-mortality functions. Using data from two climate models, we calculated future daily average temperatures in each city under Representative Concentration Pathway 6.0. Holding population constant at 2010 levels, we combined the temperature data and cluster-based temperature-mortality functions to project city-specific temperature-attributable premature deaths for multiple future years which correspond to a single reporting year. Results within the reporting periods are then averaged to account for potential climate variability and reported as a change from a 1990 baseline in the future reporting years of 2030, 2050 and 2100.ResultsWe found temperature-mortality relationships that vary by location and time of year. In general, the largest mortality response during hotter months (April – September) was in July in cities with cooler average conditions. The largest mortality response during colder months (October–March) was at the beginning (October) and end (March) of the period. Using data from two global climate models, we projected a net increase in premature deaths, aggregated across all 209 cities, in all future periods compared to 1990. However, the magnitude and sign of the change varied by cluster and city.ConclusionsWe found increasing future premature deaths across the 209 modeled U.S. cities using two climate model projections, based on constant temperature-mortality relationships from 1997 to 2006 without any future adaptation. However, results varied by location, with some locations showing net reductions in premature temperature-attributable deaths with climate change.Electronic supplementary materialThe online version of this article (doi:10.1186/s12940-015-0071-2) contains supplementary material, which is available to authorized users.

Impact of climate change on heat-related mortality in Jiangsu Province, China

“…Our findings of increasing future heat-related mortality are broadly consistent with previous assessments (Guo et al, 2016; Kingsley et al, 2016; Li et al, 2015; Petkova et al, 2013; Schwartz et al, 2015; Vardoulakis et al, 2014), though direct comparison of the effect estimates is difficult as different climate models, scenarios, downscaling methods, time periods, ERFs, and population growth scenarios were used in those previous studies. To allow a rough comparison between this study and previous studies, we computed the future changes in heat-related deaths per 100,000 people under the no population change scenario.…”

Projected temperature-related deaths in ten large U.S. metropolitan areas under different climate change scenarios

“…Additionally, we provided a detailed assessment of the future risk associated with exposure to both hot and cold temperatures in each of the 10 metropolitan areas. Previous work examining the impact of a shifting temperature distribution on both heat-related and cold-related mortality focused on regional trends by clustering large groups of climatologically similar cities together for analysis (Schwartz et al 2015). By carrying out our analysis at a finer scale (i.e., metropolitan areas), we provide evidence of direct relevance to local officials, yet still with a national scope in order to highlight the importance of this issue across the US.…”

“…In this dataset, each city is defined as the county or set of counties in which that city is located (see Supplemental Material, Table S1) (Schwartz et al 2015, Lee et al 2014). We obtained daily mean temperature values for each city from the National Oceanic and Atmospheric Administration (NOAA), as measured at the same set of airport weather stations used in previous work (Gasparrini et al 2015).…”

“…A few previous studies have considered the impact of temperature changes across the calendar year through the end of the century in various locations within the United States (US) (Li et al 2013, Mills et al 2015, Schwartz et al 2015). For example, Schwartz et al (2015) estimated that most US regions would experience a net increase in temperature-related mortality due to projected temperature changes.…”

“…For example, Schwartz et al (2015) estimated that most US regions would experience a net increase in temperature-related mortality due to projected temperature changes. Such analyses have also been carried out in the United Kingdom, Australia, Canada, and the Netherlands (Guo et al 2016, Hajat et al 2014, Huynen and Martens 2015, Martin et al 2012, Vardoulakis et al 2014).…”