Evaluating Global Climate Change Impacts on Local Health Across a Diverse Urban Region

ISEE-228 Introduction: Heat waves and high ozone have been associated with increased death and hospitalization rates in a variety of urban populations and geographies. Global-scale models project future climate changes yet have seldom been used by health scientists because of their coarse resolution (hundreds of kilometers). Finer scale climate modeling is needed to predict local effects of climate variability and change that may increase the frequency and intensity of heat and ozone episodes and result in additional mortality and morbidity. The purpose of this study is to evaluate the potential health impacts of climate-related changes in temperature and ozone air quality modeled for three future decades -- the 2020s, 2050s, and 2080s -- as compared to the 1990s, at a 36 km or finer scale. Methods: The model system used for this study links the Goddard Institute for Space Studies (GISS) Global Atmosphere-Ocean Model; the Penn State/NCAR MM5 mesoscale meteorological model; and the Community Multiscale Air Quality (CMAQ) model for simulating air quality. Simulations are performed using greenhouse gas emissions projections from the Intergovernmental Panel on Climate Change (IPCC) A2 scenario. The GISS global climate model at 4 × 5 degree horizontal resolution is used as input to the MM5 model (run at nested grids down to 36 km or finer resolution). MM5 output subsequently serves as input for the CMAQ ozone simulations. Concentration-response functions from the epidemiological literature describing temperature-related and ozone-related mortality/morbidity relationships are applied in a risk assessment model to estimate heat- and ozone-related health impacts, and to compare 1990s estimates versus 2020s, 2050s, and 2080s projections. Results: Preliminary analysis of heat-related mortality in a typical summer of the 2050s suggests a doubling to tripling of regional summer heat deaths possible by the 2050s, as compared to the 1990s. A parallel evaluation of ozone-related mortality suggests a more subtle increase in the number of summer deaths in the region in the 2050s as compared to the 1990s. At slightly coarser grid scales, analyses of combined summer and winter climate changes project a net increase in annual mortality across the region. Discussion: This work demonstrates that there is appreciable geographic heterogeneity in climate-related health impacts within a given urban region. Possible adaptive measures can be more effectively planned by city, county, and regional agencies using the linked impacts modeling system as a tool to identify those neighborhoods most at risk of increased mortality and morbidity from climate-related environmental change.