Extreme Heat and Societal Vulnerability in a Changing Climate Olga Wilhelmi NCAR / Research Applications Program NCAR Colloquium on Statistical Assessment of Extreme Weather Phenomena under Climate Change, Boulder, CO June

Defining “extreme” heat  Weather that has significant impacts is usually climatologically rare  Climatological perspective  Absolute threshold (e.g., daily minimum temperature exceeds 25 °C)  Tails of the climatological distribution for a location (e.g., temperature above the 97 th percentile).  Societal perspective  High impact events that produce significant losses  Integrated perspective  Societal impacts of extreme weather help determine climatological measures of extremes (empirical models or time series)

 Extreme heat and climate change are public health concerns  Health impacts of extreme temperatures  Heat waves can be deadly, especially in cities  Urban heat island  Impacts (health outcomes) are distributed unevenly  Societal vulnerability (including adaptive capacity)  Heat-related deaths are preventable  Ability to prepare, cope and adapt  Relationship between human health and extreme heat is a complex medical, social and environmental issue Outline

Climate change, heat and health

Health outcomes from heat  Due to effort but inability of the human body to regulate its normal internal temperature over a period of time.  Direct outcomes: heat-related edema, rash, cramps, exhaustion, and stroke.  Stroke (core body temperature above 41 o C) is medical emergency.  “classic” and “exertional” or “exercise-induced”  Indirect outcomes: respiratory, cardiovascular and diabetes-related conditions may be exacerbated by heat stress.

Patients being treated during the French heat wave of Photo: Martin Bureau/AFP From U. Bickis, Health Canada Russian heat wave” of 2010 (photo: Moscow Times) - “black swan” event Extreme heat events

Extreme heat in hot climates People are waiting for the bus in Phoenix, AZ. Photo: O. Wilhelmi

Thresholds  “The challenge lies in determining at which point the weather conditions become sufficiently hazardous to human health in a given population to warrant intervention.” (Kovats & Hajat, 2008)  Physical thresholds  Epidemiological studies help identify “minimum mortality temperature”  T min, T man, T mean, Heat Indices, Air masses  Population: all ages, over 55, 64-75, etc.  Physical thresholds vary among geographic locations and population groups  Heat health outcomes depend on societal vulnerability and adaptation to heat

Societal vulnerability  Vulnerability is the susceptibility of people or systems to damage or harm  Health outcomes are a product of extreme weather conditions and vulnerability.  Function of  exposure - conditions of the natural and built environment that position a system to be affected by extreme heat  sensitivity - the degree to which a system is affected by extreme heat  adaptive capacity - the ability or potential of a system to modify its features and behaviors to better cope with or adapt to extreme heat  Vulnerability is complex, dynamic, and spatially and temporally variable.

Scale of assessments  Assessments help identify regions and populations at risk and develop targeted interventions  National and regional assessments can mask communities living in marginal conditions  Hazard mitigation and climate change adaptation measures have to be adjusted for local ecology and appropriate level of decision making  Local-level assessment ensures more targeted intervention, response, adaptation. Community participation and buy in is critical.  Top down/bottom up approach is essential Borden et al O’Brien et al. 2004

Extreme heat vulnerability Wilhelmi and Hayden (ERL, 2010)

Drivers  Climate change:  Changes in extremes  Uncertainty  Urbanization  UHI, population density  Demographic changes  Ageing  Changing family structure Ganguly et al. 2010

Ageing RegionPercentPopulation Europe ,118 Northern America ,493 Latin America and the Caribbean ,078 Oceania18.7 9,581 Asia ,053 Africa ,538 Percent and Total Population Over Age 65, 2050 Source: Population Division of the UN Department of Economic and Social Affairs 2008

Urban heat island  Urban heat island  “Urban” climate  Paved surfaces and built structures absorb shortwave radiation during the day and release long-wave radiation with increasing intensity in the afternoon and evening  Heat exposure  The urban canyons reduce air flow and trap heat near the surface  Land surface characteristics affect heat distribution within cities (e.g., parks vs parking lots)

Sensitivity  Demographic and socioeconomic characteristics  Elderly  Very young  Obese  Poor  Mentally ill  Socially isolated  Pre-existing health conditions  Lack air conditioning  Work outdoors

Adaptive capacity  Adaptive capacity reflects a population’s potential to reduce harm in a changing environment, from current and future extreme weather.  Adaptive capacity is context-specific and dynamic  Influenced by  availability of information and technology  access to material, economic, and human resources  institutional capabilities  and knowledge, attitudes, practices, and beliefs.  social capital, including social networks that connect individuals to community resources  Measuring adaptive capacity is challenging  adaptive capacity is often nuanced and best examined qualitatively or at the household level

Adaptation and response  Extreme heat preparedness and climate adaptation plans  Coordinated Heat Watch/Warning systems  Programs that improve access to services/resources  Social and behavioral changes  Changes to physical environment

The Phoenix case study  Study objective:  Understand adaptive capacity of the vulnerable population  Examine heat risk awareness and responses in neighborhoods with variable degrees of vulnerability  The greater Phoenix, AZ area has an average of 26 deaths ( ) every summer season from exposure to excessive heat (AZ Dept. of Health Services 2009).  In 2009, Maricopa County reported 71 heat-related deaths (V. Berisha, pers. communication, 2010).

Demographics of Heat Mortality in Phoenix/Maricopa County  Younger population at risk  Indoors / Outdoors mortality cases correlate with Older/ Younger population groups respectively  Combination of socio- economic and behavioral risk factors  Homeless population Year2005 n (%) n (%) N49146 Sex Male40 (82)103 (76) Female9 (18)33 (24) Race White35 (71)115 (85) Black7 (14)10 (7) Other7 (14)11 (8) Ethnicity Non-Hispanic37 (76)58 (62) Hispanic11 (22)32 (34) Other1 (2)3 (3) Homeless16 (33)34 (25) Place of death Indoors14 (38)32 (34) Outdoors23 (62)62 (66) Age (years) Mean (range)59.8 (25-92)56.4 (7-92) Median5455 Source: Yip et al Int J Biometeorolology

Exposure and sensitivity  Identifying relative importance of heat / health risk factors by exploring exposure/sensitivity and health outcomes on a neighborhood scale (Uejio et al. 2011)  Urban ecology, characteristics of the built environment, neighborhood stability  Aggregate demographic data cannot capture individual behaviors and responses  Needs to be contextualized by household-level data on adaptive capacity

Adaptive capacity: 2009 survey  Questionnaire focused on indicators of adaptive capacity (e.g., KAP; social capital, household and community resources)  Three vulnerable neighborhoods Diverse poverty levels (11%, 22%, 44%) Ethnic and racial diversity Previous cases of mortality and heat distress calls  359 semi-structured surveys at the randomly selected households  Neighborhoods demographics:  Mean age: 40.9  Education: 32.8%- less than high school; 3.9 % - college graduate  Race / Ethnicity: 67.7% Hispanic /Latino; 17.1% African American / Black; 11.6% Caucasian ; 3.9 % American Indian

Awareness of heat illness % Symptoms identified

Awareness about extreme heat Source of heat warnings Sheridan (2007): Phoenix survey of elderly showed 90% were aware of heat warnings Phillips and Morrow (2007); Morss and Hayden (2010): television a trustworthy and expert source of hazard information and recommendations %

Awareness of available resources for coping with heat  Respondents were unaware of the resources available to them through city programs to repair air conditioners and assist with payment of electric bills.  In 2009 Phoenix had 51 hydration stations and 42 heat refuge stations (cooling shelters). %

Coping with extreme heat %

Indoor and outdoor heat risk %

Chi-square = P =.000 Differential coping capacity Chi-square = P =.000

Social capital and community networks

Improving outcomes  Access to information  All of the neighborhoods could benefit from improved access to information about available city-wide resources to reduce risk from extreme heat.  Weather – Public Health partnerships  Dissemination of critical information about resources for coping along with heat warnings.  Potential role for local TV broadcast meteorologist.  Social capital  Multi-service centers could provide a cooling shelter coupled with community outreach programs.  Community-wide efforts to ensure that neighbors, social workers and home health care providers check on socially isolated residents.  Surveys can provide more up-to-date information on vulnerability  Impact of unemployment (38%) and limited household resources contributed to higher vulnerability in neighborhoods with higher SES  Need better understanding of social and behavioral aspects of vulnerability to ensure more targeted interventions and adaptation strategies.

Current and future impacts of extreme heat  How does extreme heat in present and future climate affect human health in environmentally, socially and economically diverse urban settings?  Need to understand the relationships among  global climate change  local meteorology and extreme events  urban land use  local environmental characteristics  previous health outcomes  social vulnerability  heat mitigation responses and climate adaptation strategies

System for Integrated Modeling of Metropolitan Extreme heat Risk (SIMMER) NASA ROSES (09-IDS09-34) RAL CGD IMAGe

SIMMER project goals  Inform climate change adaptation and public health interventions in order to reduce current and future vulnerability to extreme urban heat  Advance methodology for assessing current and future urban vulnerability from heat waves through integration of physical and social science models, research results, and remote sensing data;  Develop a system (SIMMER) for building local capacity for heat hazard mitigation and climate change adaptation in the public health sector.

Filling the gaps  Determining the combined impact of extreme heat and the characteristics of urban environmental and social systems on human health  Characterizing societal vulnerability and the responses (i.e., mitigation and adaptation strategies)  Improving representation of urban land cover and its accompanying radiative and thermal characteristics at local and regional scales  Characterizing and modeling present and future extreme heat events at regional and local scales  Quantifying uncertainty

Summary  Empirical studies and model simulations suggest increasing health risks associated with climate change and extreme heat events  Relationship between human health and extreme heat is a complex medical, social and environmental issue  Research challenges:  Thresholds for warnings and advisories  Measuring adaptive capacity  Changing patterns of extreme events  Dynamic social vulnerability and adaptive capacity  Predictive heat health models  Preparedness and adaptation:  Reducing vulnerability  Engagement of stakeholders from both the top-down and the bottom-up allows the opportunity to better characterize health risks and develop policies for public health climate adaptation

Thank you!  For more information:  Wilhelmi OV, Hayden MH Connecting people and place: a new framework for reducing urban vulnerability to extreme heat. Environmental Research Letters. 5:  Hayden MH, H Brenkert-Smith, OV Wilhelmi. Differential Adaptive Capacity to Extreme Heat: A Phoenix, AZ Case Study. Submitted to Weather, Climate and Society  Morss, RE, OV Wilhelmi, G. Meehl, L. Dilling Improving Societal Outcomes of Extreme Weather in a Changing Climate: An Integrated Perspective. Annual Review of Environment and Resources