Climate Change, Extreme Heat, and Public Health Jeremy Hess, MD, MPH, FACEP Assistant Professor, Emergency Medicine, Environmental Health Emory University Schools of Medicine and Public Health Consultant, Climate Change Program, CDC Yale School of Public Health Alumni Day

Overview My opinions alone, and no conflicting interests to report Today is not a good day to die (of heat stroke) Sinks, bathtubs, and thermodynamics If not now, then when? So what do we do?

NO HEAT DEATHS TODAY Sunny, clear, high 74°F, low 54°F

Heat Mortality, US

Thermal Homeostasis Population is aggregate of individuals Individual heat budgets Narrow physiological temperature range – Behavioral maintenance – Physiological maintenance Heat exhaustion Heat stroke Humidity matters (AT, THI)

Handling Heat Illness

Susceptibility Factors Protective Intact thermoregulatory mechanisms – Sweating – Thirst – Renal function – Cardiovascular function Intact recognition of adverse exposure Intact behavioral response Resources Agency Social capital Harmful Impaired thermoregulation – Impaired sweating (anticholinergics) – Impaired thirst impulse – Kidney and CV disease – Obesity Impaired cognition Impaired behavioral response Inadequate access to preventive resources Social isolation Lack of agency

Human Heat Exposure Exposure Susceptibility Hazard

Hotlanta

Hotlanta (at Night)

Abundant Examples Chicago, 1995California, 2006

SINKS, BATHTUBS, AND THE LAWS OF THERMODYNAMICS Climate Variability and Long Term Change

GHG Concentrations Last 10K Yrs CO 2 CH 4 NO x

CO 2 and Temperature

2010 Tied for Warmest Year

ALUMNI DAY, 2091 Sunny, hazy, high 92°F, low 70°F

Heat Mortality, US

Evolving Estimates 0.6°C temperature rise to date Projections suggest 10x that by 2100 Increasing heat wave: Frequency Severity Threats to long-term habitability of large portions of the planet

Projected Change,

Projected Change,

Number of Days over 100F

Shifting Temperature Distributions

Heat Waves A period of abnormally and uncomfortably hot and usually humid weather Combination of high temps and stagnant air masses Persistent – days to weeks

European Heat Wave 2003 UK2,091 Italy3,134 France14,802 Portugal1,854 Spain4,151 Switzerland975 Netherlands1,400-2,200 Germany1,410 TOTAL29,817-30,617

Did CC Make It More Likely?

75% of Add’l Risk Anthropogenic

What the Future Holds Stott PA, Stone DA, Allen MR. Human contribution to the European heat wave of Nature 2004, doi: /nature03089.

SO WHAT DO WE DO? Mitigation and Adaptation

Mitigation Health Benefits

Moving Our Coping Range Public Health Adaptation

Scenario Based Planning Historical TrendsLinear Projections

Projected Extremes 100 US Cities Projected average (2035) Projected extreme value distributions

In Conclusion Heat is already the country’s leading weather-related cause of death Heat is also associated with a significant burden of morbidity Our GHG emissions are adding to the atmospheric sink faster than it is depleted The result is a steady, delayed, significant warming Temperatures will increase, but the greatest concern is in the extremes Mitigation is fundamentally important – remember the delay! Adaptation is necessary now and will need to be increasingly aggressive in the future

Thank you!