title: Projections of temperature-attributable premature deaths in 209 U.S. cities using a cluster-based Poisson approach.
abstract: BACKGROUND
  A 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.
  
  
  METHODS
  We 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.
  
  
  RESULTS
  We 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.
  
  
  CONCLUSIONS
  We 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.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA. joel@hsph.harvard.edu.|Department of Epidemiology, Harvard University, Boston, MA, USA. joel@hsph.harvard.edu.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Schwartz
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA. mil724@mail.harvard.edu.|Department of Epidemiology, Harvard University, Boston, MA, USA. mil724@mail.harvard.edu.
authors.forename: Mihye
authors.initials: M
authors.lastname: Lee
authors.affiliation: Columbia Climate and Health Program, Mailman School of Public Health at Columbia University, New York, NY, USA. plk3@columbia.edu.
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Kinney
authors.affiliation: Columbia Climate and Health Program, Mailman School of Public Health at Columbia University, New York, NY, USA. suka.ysj@gmail.com.
authors.forename: Suijia
authors.initials: S
authors.lastname: Yang
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, CO, 80302, USA. dmills@stratusconsulting.com.
authors.forename: David
authors.initials: D
authors.lastname: Mills
authors.affiliation: Climate Change Division, U.S. Environmental Protection Agency, Washington, DC, USA. sarofim.marcus@epa.gov.
authors.forename: Marcus C
authors.initials: MC
authors.lastname: Sarofim
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, CO, 80302, USA. rjones@stratusconsulting.com.
authors.forename: Russell
authors.initials: R
authors.lastname: Jones
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, CO, 80302, USA. rstreeter@stratusconsulting.com.
authors.forename: Richard
authors.initials: R
authors.lastname: Streeter
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, CO, 80302, USA. astjuliana@stratusconsulting.com.
authors.forename: Alexis St
authors.initials: AS
authors.lastname: Juliana
authors.affiliation: Abt Associates, 1881 Ninth Street, Suite 201, Boulder, CO, 80302, USA. jpeers@stratusconsulting.com.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Peers
authors.affiliation: Center for Climate Systems Research, Columbia University, New York, NY, USA. rh142@columbia.edu.
authors.forename: Radley M
authors.initials: RM
authors.lastname: Horton
mesh_terms: D002947:Cities; D057231:Climate Change; D006801:Humans; D008962:Models, Theoretical; D009026:Mortality / Q000639:trends*; D016012:Poisson Distribution; D012621:Seasons; D013696:Temperature; D014481:United States / Q000453:epidemiology