Health Impacts of Climate Variability and Change Kristie L. Ebi, Ph.D., MPH June 2006
Pathways for Weather to Affect Health: Diarrheal Disease Temperature Humidity Precipitation Distal Causes Proximal CausesInfection HazardsHealth Outcome Living conditions (water supply and sanitation) Food sources and hygiene practices Survival/ replication of pathogens in the environment Contamination of water sources Rate of person to person contact Consumption of contaminated water Consumption of contaminated food Contact with infected persons Incidence of mortality and morbidity attributable to diarrhea Vulnerability (e.g. age and nutrition) Contamination of food sources
Potential Health Effects of Climate Variability and Change Variability and Change
IPCC TAR–Potential Health Impacts of Climate Change Increase in the geographic range of potential transmission of malaria & other vector-borne diseases Increase in heatwaves, often exacerbated by increased humidity & urban air pollution Any increase in flooding could increase drowning, diarrheal & respiratory diseases Increase in water- and food-borne diseases The severity of impacts will depend on the capacity to adapt & its effective deployment
Drivers of Health Issues Population growth Urbanization Public health funding Scientific developments Environmental conditions Populations at risk –Poor –Children –Increasing population of elderly residents –Immunocompromised
Estimating the Global Health Impacts of Climate Change Campbell-Lendrum et al What will be the total potential health impact caused by climate change (2000 to 2030)? How much of this could be avoided by reducing the risk factor (i.e. stabilizing greenhouse gas (GHG) emissions)?
Comparative Risk Assessment 2020s 2050s 2080s Greenhouse gas emissions scenarios Global climate modelling: Generates series of maps of predicted future climate Health impact model: Estimates the change in relative risk of specific diseases Campbell-Lendrum et al Time 2080s2050s2020s
Criteria for Selection of Health Outcomes Sensitive to climate variation Important global health burden Quantitative model available at the global scale –Malnutrition (prevalence) –Diarrhoeal disease (incidence) –Falciparum malaria (incidence) –Inland and coastal floods (mortality) –Heat and cold related CVD mortality Campbell-Lendrum et al. 2003
Exposure: Alternative Future Projections of GHG Emissions Unmitigated current GHG emissions trends Stabilization at 750 ppm CO 2 -equivalent Stabilization at 550 ppm CO 2 -equivalent levels of GHGs with associated climate Source: UK Hadley Centre models Campbell-Lendrum et al. 2003
Floods Malaria Diarrhea Malnutrition DALYs (millions) Deaths (thousands) Estimated Death and DALYs Attributable to Climate Change Campbell-Lendrum et al. 2003
Climate Change vs. Urban Air Pollution Climate change Urban Air Pollution Burden of disease by region: Climate change and urban air pollution. Disability Adjusted Life Year per million. World Health Report Africa Region South-East Asia Region Eastern Mediterranean Region Latin America and Caribbean Region Western Pacific Region Developed Countries Millions of DALYs
Conclusions Climate change may already be causing a significant burden in developing countries Unmitigated climate change is likely to cause significant public health impacts out to 2030 –Largest impacts from diarrhea, malnutrition, and VBD Uncertainties include: –Uncertainties in projections –Effectiveness of interventions –Changes in non-climatic factors Campbell-Lendrum et al. 2003
Maximum Temperature August 10, 2003
Chicago – Midway (July Daily Maximum) 18.1° C21.8° C 25.5° C 29.2° C32.9° C36.6° C40.2° C Standard deviation = 3.7° C 6.7° F Now 29.2° C 84.6° F GFDL ° C 92.7° F 43.9° C47.6° C 64.6° F71.2° F 77.9° F 84.6° F91.2° F97.9° F104.4° F111.0° F117.7° F p = 36.3% p = 5.7% 35.0° C 95.0° F
Emission Pathways, Climate Change, and Impacts on California Hayhoe et al ScenarioB1A1fi Heatwave days (Los Angeles) 4X6-8X Length of heatwave season 5-7 weeks 9-13 weeks Heat-related mortality (Los Angeles) 2-3X5-7X
Health Impacts of Floods Philip Wijmans, LWF/ACT Mozambique, March 2000 Immediate deaths and injuries Immediate deaths and injuries Non specific increases in mortality Non specific increases in mortality Infectious diseases leptospirosis, hepatitis, diarrhoeal, respiratory, & vector-borne diseases Infectious diseases – leptospirosis, hepatitis, diarrhoeal, respiratory, & vector-borne diseases Exposure to toxic substances Exposure to toxic substances Mental health effects Mental health effects Increased demands on health systems Increased demands on health systems
Floods in Europe Source: "EM-DAT: The OFDA/CRED International Disaster Database, - Université Catholique de Louvain - Brussels - Belgium" Created on: May Data version: v : 1346 killed in Tajikistan 1993: 125 died in Yekaterinburg, Russia 1996: 86 died in the Biescas campsite, Spain 1998: 147 died in Sarno, Italy 2002: 120 died in Central Europe
2000 Flood in Mozambique Heavy rains from Cyclones Connie and Eline in February 2000 caused large scale flooding of the Limpopo, Incomati, Save, and Umbeluzi rivers –Environmental degradation and poor river system management and protection contributed to the crisis 700 people died, 250,000 people were displaced and 950,000 required humanitarian assistance (of which 190,000 were children under the age of 5) –14,800 people were rescued by helicopter
Average Relative Change in Malaria Incidence Before, During, and After El Niño Events, Venezuela Mean Change 0 (Niño) Time Lag (years) Coast ( ) Whole country Average of both Bouma & Dye 1997
0°C average in Jan “freeze line” 0°C average in Jan “freeze line”
Malaria in Zimbabwe Patterns of stable transmission follow pattern of precipitation and elevation (which in turn influences temperature) >9,500 deaths and 6.4 million cases between Recent high-altitude outbreaks Cases by Month Source: South African Malaria Research Programme Ebi et al. Submitted
Climate and Stable Malaria Transmission Climate suitability is a primary determinant of whether the conditions in a particular location are suitable for stable malaria transmission A change in temperature may lengthen or shorten the season in which mosquitoes or parasites can survive Changes in precipitation or temperature may result in conditions during the season of transmission that are conducive to increased or decreased parasite and vector populations Ebi et al. 2005
Baseline Ebi et al. 2005
2025 Ebi et al. 2005
2050 Ebi et al. 2005
2075 Ebi et al. 2005
2100 Ebi et al. 2005
Climate Change and Malaria Under Different Scenarios (2080) Increase: East Africa, Central Asia, Russian Federation Decrease: Central America, Amazon [within current vector limits] A1 B2 A2 B1 Van Lieshout et al. 2004
Effect of Temperature Variation on Diarrheal Incidence in Lima, Peru Daily Temperature Daily Diarrhea Admissions Diarrhea increases by 8% for each 1 ºC increase in temperature Checkley et al. 2000
Temperature-Salmonella Models [fully adjusted] England & Wales Scotland Switzerland Netherlands
China Haze 10 January 2003 NASA
Air Pollution and Health Number of days with surface ozone >180 µg/m Summer 2003 EEA
Current and projected ranges of beech trees in the U.S. Current growth Projected new growth GFDL — Geophysical Fluid Dynamics Laboratory GISS — Goddard Institute for Space Studies Current range GFDL scenario GISS scenario Source: U.S. Environmental Protection Agency, 1998.
Adaptation Needed Because: Climate change can not be totally avoided Climate change may be more rapid and more pronounced than current estimates The severity of impacts will depend on the capacity to adapt and its effective deployment –Immediate benefits can be gained from better adaptation to climate variability and extreme events Climate change brings opportunities as well as threats
Thank you