Health Impacts of Climate Health Impacts of Climate Variability and ChangeVariability and Change

Kristie L. Ebi, Ph.D., MPHkrisebi@essllc.org

June 2006

Pathways for Weather to Affect Pathways for Weather to Affect Health: Diarrheal DiseaseHealth: Diarrheal Disease

TemperatureHumidityPrecipitation

Distal Causes Proximal Causes Infection Hazards Health Outcome

Living conditions(water supply andsanitation)

Food sources andhygiene practices

Survival/ replicationof pathogens in theenvironment

Contamination ofwater sources

Rate of personto person contact

Consumption ofcontaminated water

Consumption ofcontaminated food

Contact withinfected persons

Incidence of mortality andmorbidityattributableto diarrhea

Vulnerability(e.g. age andnutrition)

Contamination of food sources

Potential Health Effects of ClimatePotential Health Effects of Climate Variability and ChangeVariability and Change

IPCC TAR–Potential Health IPCC TAR–Potential Health Impacts of Climate ChangeImpacts 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 IssuesDrivers 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 Estimating the Global Health Impacts of Climate ChangeImpacts of Climate Change

Campbell-Lendrum et al. 2003Campbell-Lendrum et al. 2003

• 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 AssessmentComparative Risk Assessment

2020s

2050s

2080s

Greenhouse gas Greenhouse gas emissions scenariosemissions scenarios

Global climate modelling:Global climate modelling:

Generates series of maps Generates series of maps of predicted future climateof predicted future climate

Health impact model:Health impact model:

Estimates the change in relative Estimates the change in relative risk of specific diseasesrisk of specific diseases

Campbell-Lendrum et al. 2003Campbell-Lendrum et al. 2003

Time

2080s2050s2020s

Criteria for Selection of Criteria for Selection of Health OutcomesHealth 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. 2003Campbell-Lendrum et al. 2003

Exposure: Alternative Future Exposure: Alternative Future Projections of GHG EmissionsProjections of GHG Emissions

• Unmitigated current GHG emissions trends

• Stabilization at 750 ppm CO2-equivalent

• Stabilization at 550 ppm CO2-equivalent

• 1961-1990 levels of GHGs with associated climate

Source: UK Hadley Centre models

Campbell-Lendrum et al. 2003Campbell-Lendrum et al. 2003

Floods

Malaria

Diarrhea

Malnutrition

020406080100120 2 4 6 8 10

DALYs (millions)Deaths (thousands)

2000

2020

Estimated Death and DALYs Attributable to Climate Change

Campbell-Lendrum et al. 2003Campbell-Lendrum et al. 2003

Climate Change vs. Urban Air Pollution

05 0 01 0 0 01 5 0 02 00 025 0 030 0 0 0 5 0 0 1 0 0 0 15 00 2 00 0 2 5 0 0 30 00

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 2002.

Africa Region

South-East Asia Region

Eastern Mediterranean Region

Latin America and Caribbean Region

Western Pacific Region

Developed Countries

Millions of DALYs

ConclusionsConclusions• 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. 2003Campbell-Lendrum et al. 2003

Maximum Temperature Maximum Temperature August 10, 2003August 10, 2003

Chicago – MidwayChicago – Midway(July Daily Maximum)(July Daily Maximum)

18.1° C 21.8° C 25.5° C 29.2° C 32.9° C 36.6° C 40.2° C

Standard deviation = 3.7° C6.7° F

Now29.2° C84.6° F

GFDL 209533.7° C92.7° F

43.9° C 47.6° C

64.6° F 71.2° F 77.9° F 84.6° F 91.2° F 97.9° F 104.4° F 111.0° F 117.7° F

p = 36.3%

p = 5.7%

35.0° C95.0° F

Emission Pathways, Climate Change, Emission Pathways, Climate Change, and Impacts on Californiaand Impacts on California

Hayhoe et al. 2004

Scenario B1 A1fi

Heatwave days (Los Angeles) 4X 6-8X

Length of heatwave season

5-7 weeks

9-13 weeks

Heat-related mortality (Los Angeles)

2-3X 5-7X

Health Impacts of FloodsHealth Impacts of Floods

Philip Wijmans, LWF/ACT Mozambique, March 2000

•Immediate deaths and Immediate deaths and injuriesinjuries

•Non specific increases Non specific increases in mortalityin mortality

•Infectious diseases Infectious diseases – leptospirosis, hepatitis, leptospirosis, hepatitis, diarrhoeal, respiratory, diarrhoeal, respiratory, & vector-borne diseases& vector-borne diseases

•Exposure to toxic Exposure to toxic substancessubstances

•Mental health effectsMental health effects

•Increased demands on Increased demands on health systemshealth systems

Floods in EuropeFloods in Europe

Source: "EM-DAT: The OFDA/CRED International Disaster Database, www.em-dat.net - Université Catholique de Louvain - Brussels - Belgium" Created on: May-23-2005. - Data version: v05.05

1992: 1346 killed in Tajikistan1993: 125 died in Yekaterinburg, Russia1996: 86 died in the Biescas campsite, Spain1998: 147 died in Sarno, Italy2002: 120 died in Central Europe

2000 Flood in Mozambique2000 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 Average Relative Change in Malaria Incidence Before , During, and After El Incidence Before , During, and After El

Niño Events, VenezuelaNiño Events, Venezuela

2.0

-2

1.8

1.6

1.4

1.2

1.0

0.8

Mean Change

-1 0 (Niño) +1 +2Time Lag (years)

Coast (1910-1935)

Whole country

Average of both

Bouma & Dye 1997

0°C average in Jan

“freeze line”

0°C average in Jan

“freeze line”

Malaria in ZimbabweMalaria 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 1989-1996

• Recent high-altitude outbreaks

Cases by Month

Source:

South African Malaria Research Programme

Ebi et al. SubmittedEbi et al. Submitted

Climate and Stable Malaria Climate and Stable Malaria TransmissionTransmission

• 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. 2005Ebi et al. 2005

Baseline

Ebi et al. 2005Ebi et al. 2005

2025

Ebi et al. 2005Ebi et al. 2005

2050

Ebi et al. 2005Ebi et al. 2005

2075

Ebi et al. 2005Ebi et al. 2005

2100

Ebi et al. 2005Ebi et al. 2005

Climate Change and Malaria Under Climate Change and Malaria Under Different Scenarios (2080)Different Scenarios (2080)

• Increase: East Africa, Central Asia, Russian Federation• Decrease: Central America, Amazon[within current vector limits]

C hange o f consecutive m onths

> +2

+2

-2

< -2

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

Average 2 month temperature

lcl rr ucl

0 5 10 15 20

0

500

1000

1500

Temperature-Salmonella Models [fully adjusted]Temperature-Salmonella Models [fully adjusted]

England & Wales

Average 2 month temperature

lcl rr ucl

0 5 10 15 20

0

50

100

150

Average 2 month temperature

lcl rr ucl

0 5 10 15

20

40

60

80

Scotland

Average 2 month temperature

lcl rr ucl

0 10 20

0

100

200

300

Switzerland

Netherlands

China Haze 10 January 2003China Haze 10 January 2003

NASA

Air Pollution and HealthAir Pollution and HealthNumber of days with surface ozone >180 Number of days with surface ozone >180 µµg/mg/m33

1999 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

GFDLscenario

GISSscenario

Source: U.S. Environmental Protection Agency, 1998.

Adaptation Needed Because: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 youThank you