Extreme Heat and Human Health Richard B. Rood and Marie S. O’Neill Richard B. Rood December 17, 2010

Funding Acknowledgments Reducing social disparities of heatwaves impacts in a changing climate –Grant from Centers for Disease Control and Prevention (Sept August 2011), Grant R18 EH –Investigators: M. O’Neill, E. Parker, R. Rood (U of Michigan); S. McCormick (George Washington U.); M. Stults, X. Manarolla (ICLEI: Local Governments for Sustainability); J. Schwartz and A. Zanobetti (Harvard U); K. Ebi (ESS/LLC) Climate change, heatwaves, and health: Local tools for sustainability, equity, and prevention –Grant from Graham Environmental Sustainability Institute, University of Michigan, ( ) –Investigators: M. O’Neill, R. Rood, E. Parker, D. Brown

Approach of this study A team of people with a range of skill sets and interests –Epidemiology –Environmental health –Health behavior and social science –Geographical information –Statistical analysis –Meteorology –Systems analysis

What do we want to tell a union of geophysicists? What does the problem-solving space look like? Where does physical climate sit in relation to other elements of the problem?

Background: Extreme heat is already a problem Extreme heat impacts human health, and more deaths are attributed to heat than any other environmental parameter. Relation between heat and impact on health is difficult to quantify. –Physics of heating and cooling –Attributes of local environment –Physiology of individuals / acclimation –Attributes of personal environment In fact, extreme heat that impacts health is hard to define. –Sheridan and Kalkstein (2004)Sheridan and Kalkstein (2004) –EPA GuidebookEPA Guidebook

Extreme Heat and Climate Change There is observational evidence of increasing episodes of extreme heat (for example, Gaffen and Ross, Nature, 1998)Gaffen and Ross There are predictions of increases in extreme heat events by climate change projections (for example, Meehl and Tebaldi, 2004)Meehl and Tebaldi See IPCC, 2007 for a more complete assessment.IPCC, 2007 Climate projections do not necessarily link to human health.

How do we use this information in a public health application? Consider another form of model study (Diffenbaugh and Ashfaq, 2010)Diffenbaugh and Ashfaq –Using a regional climate model resolving North America they focus on the next 30 years. –This period is expected to be well below the putative dangerous climate change threshold of a 2° C –What is the change in events that look like historical heat waves in the next 30 years? –Result: In see 6 extreme events per decade as compared with ~ 1 per decade in Heat risk, potential danger to human health increases, even if there is aggressive adoption of mitigation policies. See Philo. Trans. Roy. Soc., Jan 2011 (4 degrees warming)Philo. Trans. Roy. Soc., Jan 2011

Schematic of System SUN WATER Ability to Cool HEAT STRESS

Schematic of System SUN WATER Ability to Cool HEAT STRESS Built Environment Amplification Accumulation

Rational Paths of Using this Information Calculation of parameters that link heat to human health. Persistent Daily Highs Persistent Daily Lows Incorporation of humidity (apparent T) Incorporation of clouds, wind, etc.

Paths of better defining “heat extremes” Persistent Daily Highs Persistent Daily Lows Incorporation of humidity (apparent T) Incorporation of clouds, wind, etc. Strenuous exertion Regional Acclimation Accumulated Heat Built Environment Ability to cool Sultriness Dehydration Information?

Improved representations of heat and humans Can we do better than just saying that it is going to get hotter? What is value of nuanced calculations of heat extremes and stress? Is it usable information? What is the balance between having to study each case and the ability to aggregate information and develop general strategies? What is the minimal level of complexity that must be accommodated?

Rational Paths of Using this Information Consideration of people who get in trouble when it is hot. Exertion Exposure Urban Heat Compromised Health

Paths of considering how people get in trouble Exertion (August football) Exposure (Crossing the border) Urban Heat Compromised Health High temperature Low temperature Built environment Accumulated heat Hot buildings High temperature Accumulated heat Inability to cool Urban Heat Built environment Accumulated heat Hot buildings Compromised Health High temperature Accumulated heat Inability to cool

Quantitative Analysis Detroit Oswald et al. (2010) J. Appl. Meteor. Clim. (submitted) Zhang et al. (2010) Environmental Research (submitted) Imperviousness  built environment  best predictor

Rational Paths of Using this Information Identification of vulnerable people and reducing the risk Population Characterization Warning Education of Public/First Providers Adaptive Capacity/Design

Summary: Heat, Humans, Climate Change Extreme heat is already an important public health risk. Projections of future heat events that are similar to dangerous heat events of the past suggest increased risk. Increase in temperature does not easily transfer over to actionable information by public health officials.

Summary: Heat, Humans, Climate Change Important considerations for making climate information more relevant to human health –Persistence of hot spells Daily lows and highs Accumulation of heat –Overlap with cities and built environment –Thresholds related to physiology –Extension of heat threats to cities and regions where heat-related risk is unexpected. Responses: –Education of at risk public \ What to do –Education of first responders –City planning –Materials

Summary: Take Away Message Responses to address extreme heat de-correlates the details of the physical science from solution. It is important to identify regions, hence cities, where heat is likely to become a risk. The cogeneration of knowledge by all disciplines represented on the team contribute to successful solutions. –Learning the language –Learning the priorities –Learning the compromises –Learning the possibilities