PA23B-2226 Mapping Extreme Heat Vulnerability and Health Outcomes to inform the District of Columbia's Climate Adaptation Plan: Progress Report Juan 1 Declet-Barreto , Olga 2 Wilhelmi , and Alexis 3 Goggans 1: Union of Concerned Scientists, Washington, DC, USA; 2: NCAR, Boulder, CO, USA; 3: Government of the District of Columbia, Washington, DC, USA [ CLIMATE CHANGE AND EXTREME HEAT [ SENSITIVITY: WHO IS SUSCEPTIBLE TO HEAT? Extreme heat presents serious public health and urban planning challenges to cities as they struggle to adapt to changing climate conditions. Human mortality and morbidity increases are triggered by summertime extreme heat events. Indeed, among weatherrelated hazards, extreme heat is the number one killer of people in the United States. In cities, extreme heat and heat waves are magnified by the Urban Heat Island effect, a phenomenon caused by urbanization and changes in land surface characteristics. Combined impacts of UHI and projected climate change may further increase risk of heat-related mortality in the U.S. cities. This dimension represents the socio-economic characteristics of the population that can magnify vulnerability to extreme heat, and includes individual risk factors known to be associated with increased heat morbidity or mortality: Photo credit: fedmanager.com • Percent Not White • Percent No High School Diploma • Percent Living in Poverty • Percent Elderly • Percent Receiving Food Stamps • Percent with Disability • Percent with no AC [ EXPOSURE: WHERE ARE THE HEAT-PRONE AREAS? This dimension captures the elements of the built environment correlated with higher temperatures, as well as 20-year average temperatures: • Percent Impervious Surface (Mean) • Percent Impervious Surface (SD) • Percent No Tree Canopy • Mean Daily Maximum Air Temperature (May-September 1995-2015) [ CLIMATE ADAPTATION PLANNING IN DC The District of Columbia’s “Climate Ready DC” Plan revealed the District will experience climate change impacts, including: • More frequent and intense heavy rain events • Higher tides as a result of rising sea level • Much higher average temperatures • Two to three times as many dangerously hot days • Longer, hotter, and more frequent heat waves However, numerous questions remain about the locations and characteristics of people and places vulnerable to extreme heat. The District government partnered with social and climate scientists to map socio-spatial distribution of heat-vulnerable populations and elements of the built environment in the District of Columbia. AGU’s Thriving Earth Exchange facilitated this partnership. [ RESEARCH QUESTIONS RQ1. What areas of the city contain the most heat-sensitive populations according to individual heat-health risk factors? RQ2. What are the areas of the city with the highest outdoor heat exposure potential due to impervious surfaces and little tree canopy cover? RQ3. What are the areas of the city most vulnerable to adverse heat-health outcomes based on sensitivity of the population and exposure in the built environment? [ METHODS We developed a heat vulnerability index (HVI) for Census Block Groups in the District of Columbia. Our HVI combines the sensitivity and exposure dimensions into an indicator of cumulative extreme heat vulnerability. We assembled social, economic, demographic, and built environment variables known in the heat health literature to be predictors of extreme heat morbidity and mortality (Harlan et al. 2013). Based on an earlier, unpublished version of the index (Larsen et al. 2014), we built individual indices to represent sensitivity and exposure. The exposure index provides information useful for policymakers tasked with modifications of the built environment, while the sensitivity indicator points out areas of population concern for public health practitioners. The HVI combines the sensitivity and exposure indices into a cumulative indicator. [ TEMPERATURE PATTERNS [ A HEAT VULNERABILITY INDEX USEFUL TO PUBLIC HEALTH AND URBAN PLANNER COMMUNITIES Our cumulative HVI map shows a nuanced pattern of heat vulnerability in the District: • Ward 3 has a mostly white and wealthy population, with lots of vegetation. It registers both low exposure and sensitivity, and thus low vulnerability scores. • Wards 7, 8, and parts of 5 have high rates of minorities, low income and other sensitive populations, thus high sensitivity scores. Exposure is moderate to high, resulting in medium to high vulnerability. • High exposure but low sensitivity in Ward 2 results in moderate vulnerability scores. • Low to medium exposure offsets high sensitivity scores in Ward 4, resulting in moderate vulnerability. Spatial analysis of modeled (Daymet) summertime air temperatures for 1995-2015 suggests there are small but consistent differences among block groups. The UHI effect contributes to higher exposure scores and has potential to amplify heat-health effects for most sensitive populations. Additional data and research are needed to better understand intra-urban variability in heat and its contribution to heat health risks. Average and seasonal temperatures in the District are expected to increase. The chart on the left shows historical and projected summer nighttime low temperatures under higher (red) and lower (orange) emissions scenarios. Lower nighttime temperatures help provide relief from hot days. ATMOS Research & Consulting, May 2015 These findings are in line with those in the 2016 Vulnerability & Risk Assessment companion report to the District’s Climate Adaption Plan: “Wards 7 and 8 are home to the largest number of residents with a higher vulnerability to climate change impacts – especially an increase in extreme heat – due to the socioeconomic factors that increase sensitivity to heat, and limit the ability to adapt, including unemployment, age (seniors and young children), and income.” (page 8) [ NEXT STEPS [ DATA SOURCES Socio-demographic variables were assembled with data from the U.S. Census Bureau’s 2010 Decennial Population Count and the American Community Survey 5Year Estimates (2010-2014). Air Conditioner data were obtained from the District of Columbia’s Computer Assisted Mass Appraisal (CAMA) database. Vegetation and impervious surface data were obtained from the University of Vermont’s “Urban Tree Canopy Summarized by Ownership Parcels” subset of the District’s Urban Tree Canopy Assessment. Temperature data were obtained from the National Climate Data Center (Dalecarlia Reservoir station, GHCND:USC00182325) and from the NASA DAYMET program (Thornton, P.E., M.M. Thornton, B.W. Mayer, Y. Wei, R. Devarakonda, R.S. Vose, and R.B. Cook. 2016. Daymet: Daily Surface Weather Data on a 1-km Grid for North America, Version 3. ORNL DAAC, Oak Ridge, Tennessee, USA. Accessed November 10, 2016. Time period: 1995-06-01 to 2015-09-01. Spatial Range: N=39.00, S=38.80, E=-76.91, W=-77.12 • Continue working with the District government to analyze heat health risks. Future research will focus on the analysis of heat-related 911 calls. These data will be used to validate HVI against heat-related incidents during warm season (May-September) • Estimate if there are significant differences in heat-related incident rates by HVI values. • Continue research to better understand spatial variability in intra-urban heat patterns • Develop indicators of adaptive capacity and integrate them into HVI. [ REFERENCES 1. Larsen, Larissa; O'Neill, Marie, White-Newsome, Jalonne; Berrocal, Veronica; Rood, Ricky; Stults, Missy; Mallen, Evan; Rajkovich, Nick; Seymour, Eric; Conlon, Katy; Ogbomo, Adesuwa; and Tran, Valerie (2014). Revised Heat Vulnerability Maps. Email communications to District of Columbia Focus Group Participants. 2. Harlan, Sharon L., Juan H. Declet-Barreto, William L. Stefanov, and Diana B. Petitti. "Neighborhood effects on heat deaths: social and environmental predictors of vulnerability in Maricopa County, Arizona." Environmental Health Perspectives (Online) 121, no. 2 (2013): 197. 3. Government of the District of Columbia. 2016. Vulnerability & Risk Assessment: Climate Change Adaptation Plan for the District of Columbia. http://doee.dc.gov/sites/default/files/dc/sites/ddoe/publication/attachments/AREA_Vulnerability_As sessment_DRAFT_2016-06-21lowres_.pdf 4. Government of the District of Columbia. 2016. Climate Change Adaptation Plan for the District of Columbia. http://www.sustainabledc.org/climatereadydc/