AJ McMichael

1
Global Warming and Climate Change Why the
Health Sector Should be Engaged SEARO Office,
New Delhi, March 2008

• AJ McMichael
• National Centre for
• Epidemiology and Population Health
• The Australian National University
• Canberra

2
Should the Health Sector Engage?

• Health risks are real and are increasing.
• Extreme weather events likely to increase Could
  overwhelm health sectors capacity.
• CC jeopardises other ongoing health gains esp.
  in low-income/vulnerable populations
• (e.g. Millennium Devt Goals HIV/AIDS pandemic
  etc.)
• 4. Health sector has, generally, been slow to
  recognise and respond to risk. Consequently
• Inadequate capacity-building (research,
  prevention, policy)
• Deficient contact/engagement with other sectors
• 5. Society has been slow to understand that
  threat to health is the most serious,
  fundamental, risk.
• Population health is ultimate marker of
  sustainability

3
Climate Change Health Impacts and Policy
Responses
Adaptation Reduce impacts
Natural processes and forcings

• Global Environmental Changes, affecting
• Climate
• Water
• Food yields
• Other materials
• Physical envtl. safety
• Microbial patterns
• Cultural assets

• Impacts on human society
• livelihoods
• economic productivity
• social stability
• health

Human pressure on environment

• Human society
• culture, institutions
• economic activity
• demography

Feedback
Mitigation Reduce pressure on environment
4
Overview of Recent CC Science

• Together, the reported GCM model runs for the 6
  IPCC emissions scenarios forecast, for 2100,
  increases in temperature (central estimate per
  scenario) of 1.4-5.8 oC.
• Most of the uncertainty reflects unknowable human
  futures (the scenarios) the rest is due to model
  uncertainties.
• A further 0.7 oC is committed (on top of the
  0.6oC already realised)
• IPCC Fourth Assessment Report (2007) already
  looks conservative. Recent studies indicate
  accelerating change.
• Political discourse in high-income countries is
  now starting to acknowledge need for 80
  reduction in emissions relative 2000.

5
Projected warming, to 2100 for six future global
greenhouse gas emissions scenarios
Intergovernmental Panel on Climate
Change (IPCC), 2007 Wkg Gp I
3 of the 6 emissions scenarios
Uncertainty range 1 standard deviation
Warming already in pipeline from existing GHG
levels (0.6oC)
A1F1
4oC
A2
1.8 - 4.0 oC
A1B
Warming (oC)
2oC
B1
23 models (tested against recent record)
1980-99 baseline temperature
A1T
B2
A1F1
16-21 models used for each scenario
No. of models used
1900 2000
2100
6 different GHG emissions scenarios
Year
6
Climate Change Faster than expected in 1990s
Solid lines observed

• IPCC 4 (2007) was limited to science
  published by early 2006
• Subsequent research shows increasing rates of
• Global GHG emissions
• 3.3 p.a. in 2000s, vs 1.3 p.a. in 1990s
• Temperature rise
• especially in polar regions
• Ice melt (Arctic 40 loss since 1980,
  accelerating 2006-07)
• Sea-level rise

Dashed lines 1990s projections
Rahmstorf, Church, et al., Science 2007
1975 1985 1995 2005
7
Intergovernmental Panel on Climate Change, WkGp2
Report (2007) Some Key Findings

• Water 75-250m Africans may face water-shortage
  by 2020.
• Crops
• Rain-fed agriculture could decline by 50 in
• some African countries by 2020.
• Crop yields could
• increase by 20 in some parts of Southeast Asia
  but
• decrease by up to 30 in Central/South Asia.
• Glaciers and snow cover Expected to decline,
  reducing supply of melt water to major regions,
  cities.
• Species 20-30 of all plant and animal species
  face increased risk of extinction if 1.5-2.5 oC
  rise.
• Scientific literature review of gt29,000 studies
  of physical and biological changes in natural
  world 89 consistent with accompanying warming.

8
Excerpt from UNDP Press Release, Nov 27
9
Climate Change Health
Physical systems (ice, rivers, etc.)
e.g. prime focus of Stern Report (UK, 2006)
Economy infrastructure, output, growth
Climate Change Impacts
Food yields
Biological seasonal cycles
Wealth (and distribution) local environment etc.
10
Cartogram Emissions of greenhouse gases
Density-equalling cartogram. Countries scaled
according to cumulative emissions in billion
tonnes carbon equivalent in 2002. Patz, Gibbs,
et al, 2007
11
Cartogram (Selected) health impacts of climate
change
Malnutrition gt diarrhoea gt malaria gt floods
Density-equalling cartogram Patz, Gibbs, et al,
2007. WHO regions scaled according to estimated
mortality (per million people) in the year 2000.
Based on burden-of-disease attribution to the
climate change that occurred from 1970s to 2000
(McMichael et al., 2003).
12
Health Impacts Summary IPCC AR4 (2007)
(IPCC, 2007)
13
Health Impacts Examples

• Thermal stress (esp. heat-waves)
• Diarrhoeal disease
• Vector-borne infectious disease
• Dengue fever
• Food yields nutrition, child development
• Disasters damage, dislocation, displacement

14
Heatwave August 2003
Land surface temperatures, summer of 2003, vs.
summers of 2000-04. NASA satellite spectrometry
35,000-50,000 extra deaths over a 2-week period
15
Seasonal variation in daily mortality pattern,
Delhi, 1991-94
60
40
Daily deaths

20
0
1jan,1991
1jan,1993
1jan,1995

16
Heat-related mortality, Delhi, 1991-94
Generalised additive model, with cubic-spline
smoothing

Relative mortality ( of daily average)
140
120
100
Uncertainty range 95 CI
80
0
10
20
30
40

Daily mean temperature (oC)
McMichael et al, ISOTHURM Study
17
Diagram of Typical Influence of Seasonal
Rainfall, Surface Water, and Crowding on Cholera
Occurrence, Madras region
Based on Ruiz-Moreno, Pascual, Bouma, et al,
EcoHealth 2007 4 52-62. Study of 26 districts,
Madras Presidency, south-east India, 1901-1940.
Ro reproductive number
Ro primary (water-borne) transmission
Ro secondary (human-to-human) transmission
human crowding effect
water dilution effect
1.0
1.0
Flood
Shallow
Water Depth
18
Domestic bamboo pole holders Found in public
housing estates
KT Goh, Singapore Ministry of Health
19
Dengues principal vector Aedes aegypti
Principal vector is female Aedes aegypti
mosquito. Infected mosquito remains infective for
life. Indonesia reported dengue cases doubled in
2007 vs. 2005.
20
Effects of Temperature Rise on Dengue
Transmission

• Shorten viral incubation period in mosquito
• Shorten breeding cycle of mosquito
• Increase frequency of mosquito feeding
• More efficient transmission of dengue virus from
  mosquito to human

21
Global Dengue Epidemiology
1960s
Thousand-fold increase in reported incidence
1990s
Dengue fever only DHF/DSS


Dengue007/CMH/260302
22
Estimated regional probability of dengue
occurrence under medium climate change scenario
2085 vs 1990Using statistical equation derived
from observations of recent distribution of
disease in relation to meterological variables
Source Hales et al. Lancet, 2002.
http//image.thelancet.com/extras/01art11175web.pd
f
Probability
23
Schistosomiasis Northwards extension of
potential transmission (limited by freezing
zone), in Jiangsu province, due to rise in
average January temperature since 1960
Temperature change from 1960s to 1990s
0.6-1.2 oC 1.2-1.8 oC
Freezing zone 1970-2000
Freezing zone 1960-1990
Baima lake
Hongze lake
planned Sth-to-Nth water canal
Yang et al, 2005 Increase in reported incidence
of schistosomiasis over past decade. May reflect
recent warming? Northwards extension of
freeze line (which limits survival of water
snails) puts 21 million extra people at risk.
Yangtze River
Shanghai
24
Zhou X-N, Yang G-J, et al. Potential Impact of
Climate Change on Schistosomiasis Transmission in
China
Recent data suggest that schisto-somiasis is
re-emerging in some settings that had previously
reached the successful disease control criteria
of either transmission control or transmission
interruption. . Along with other reasons,
climate change and ecologic transformations have
been suggested as the underlying causes.
25
Baseline 2000 2025 2050
Climate Change Malaria (potential transmission)
in Zimbabwe
Harare
Ebi et al., 2005
26
Baseline 2000 2025 2050
Climate Change Malaria (potential transmission)
in Zimbabwe
Ebi et al., 2005
27
Baseline 2000 2025 2050
Climate Change Malaria (potential transmission)
in Zimbabwe
Ebi et al., 2005
28
General Relationship of Temperature and
Photosynthesis
100
Photo-synthetic activity
2oC ?
2oC ?
0
20o C
30o C
40o C
C Field D Lobell. Environmental Research
Letters, 2007 A 1oC increase reduces global
cereal grain crop yields by 6-10. So, a rise of
2oC could mean 12-20 fall in global production.
Note this estimate is higher than most others.
29
Climate change impacts on rain-fed cereal
production, 2080 (IIASA Fischer et al, 2001)
30
Population
31
Climate Change Health Impacts and Policy
Responses
Adaptation Reduce impacts
Natural processes and forcings

• Global Environmental Changes, affecting
• Climate
• Water
• Food yields
• Other materials
• Physical envtl. safety
• Microbial patterns
• Cultural assets

• Impacts on human society
• livelihoods
• economic productivity
• social stability
• health

Human pressure on environment

• Human society
• culture, institutions
• economic activity
• demography

Feedback
Mitigation Reduce pressure on environment
32
CC and Health Main Types of Adaptive Strategies

• Public education and awareness
• Early-alert systems heatwaves, other impending
  weather extremes, infectious disease outbreaks
• Community-based neighbourhood support/watch
  schemes
• Climate-proofed housing design, and cooler
  urban layout
• Disaster preparedness, incl. health-system
  surge capacity
• Enhanced infectious disease control programs
• vaccines, vector control, case detection and
  treatment
• Improved surveillance
• Risk indicators (e.g. mosquito numbers,
  aeroallergen concentration)
• Health outcomes (e.g. inf dis outbreaks, rural
  suicide rates, seasonal asthma peaks)
• Appropriate workforce training and mid-career
  development

33
Use of climate-health time-series data to develop
a Malaria Early Warning System (Botswana)
Observed summer (Dec-Feb) rain
Forecast (advance- modelled) summer rain
Highest malaria incidence years (versus)
Log malaria incidence
Relationship between summer rainfall and
subsequent annual malaria incidence
Lowest malaria incidence years
Summer Precipitation (mm / day)
Precipitation anomaly (mm / day)

• Thomson M, et al. Summer rain and subsequent
  malaria annual incidence in Botswana. Nature
  2006 439 576-9

34
Climate Change and Health Dual Purpose of
Research

• Enhance Health Protection, at two levels
• 1. Recognition of health risks will potentiate
  true primary prevention i.e. the reduction of
  GHG emissions. (Which may also revitalise Health
  Promotion) Meanwhile .
• 2. Health risks already exist and more are
  unavoidable. So, we must develop and evaluate
  adaptive (secondary prevention) strategies.

35
Conclusion Plenty to be worried about but big
chance to play a key role in achieving a global
solution, revitalised health promotion and true
Sustainability
36
Climate Change Health Core Categories of
Research
Empirical data-based studies
Scenario-based future-health risk assessment
2. Detect impacts 3. Estimate current
burden
4. Predictive estimation (eg, modelling)
1. Learn CC-health relations
Past
Present
Future
Adaptive strategies
37
Climate Change and Geopolitical Security

• Climate change of the order and time frames
  predicted by climate scientists poses fundamental
  questions of human security, survival and the
  stability of nation states which necessitate
  judgments about political and strategic risks as
  well as economic cost.
• Heating Up the Planet Climate Change and
  Security.
• Dupont A, Pearman G, Lowy Institute Paper 12, 2006

38
Deaths and DALYs attributable to Climate Change,
2000 2030 Selected conditions in developing
countries
Deaths
Total Burden
Now (2000)
Future (2030)
Deaths (thousands)
DALYs (millions)
McMichael et al/WHO, 2004
2000
2030
39
Impacts, Vulnerability, Adaptations
Characteristics of exposed group (location,
wealth, resources, health status, culture, etc.)
Adaptations
Vulnerability of group
Learning
Actions in response to impact
Health Impact
Exposure
Mitigation Reduced exposure
40
Projected warming, to 2100 for six future global
greenhouse gas emissions scenarios
Intergovernmental Panel on Climate
Change (IPCC), 2007
3 of the 6 emissions scenarios
Uncertainty range 1 standard deviation
Warming already in pipeline from existing GHG
levels (0.6oC)
A1FI
4oC
A2
1.8 - 4.0 oC
A1B
Warming (oC)
2oC
B1
23 models (tested against recent record)
1980-99 baseline temperature
A1T
B2
A1FI
16-21 models used for each scenario
Range of estimates for all GCM model runs of B1
scenarios emissions
No. of models used
1900 2000
2100
6 different GHG emissions scenarios
Year
41
Malaria in Tawau, Sabah
Source VBDCP, MOH
42
Global rise in dengue cases reported annually to
WHO, 1955-2005
925,896
1,000,000
One thousand-fold increase
800,000
479,848
600,000
295,554
400,000
122,174
200,000
15,497
908
0
1955-59
1960-69
1970-79
1980-89
1990-99
2000-
2005
Lancet 20063682194
43
Health Co-Benefits from GHG Emissions Mitigation
Actions Revitalised Health Promotion?

• Reduce fossil fuel combustion
• Reduce cardio-respiratory deaths/hospitalisations
  from local air pollution (esp. fine
  particulates).
• Low-emission urban (public) transport system
• Increase physical activity (walking, cycling) ?
  reduce over-weight, improve lipid/endocrine
  profiles, increase social contact and wellbeing.
• Road trauma should decline.
• Reduce red (ruminant) meat consumption (livestock
  sector is major source of GHG emissions, esp.
  methane)
• Reduce risks of some disease large bowel cancer,
  ?breast cancer also heart disease (meat fat
  content).
• More energy-efficient housing
• Reduce family costs, and (especially for
  lower-income households) reduce thermal stress
  and debt-related mental stress.

44
Tasks for policy-makers

• Integrate health risk assessment into impact
  assessments carried out by non-health sectors
• Understand the intrinsic uncertainties in this
  topic, including unavoidable uncertainties about
  projected future risks
• Identify vulnerable communities and
  sub-populations
• Develop and evaluate adaptive strategies/intervent
  ions to reduce both present and likely future
  risks to health from climate change
• Coordinate development of policy and programs at
  local, national and international levels
• Recognise need for governmental regulatory
  involvement as basis of societal response to this
  (and other) global environmental problem(s)

45
Achieving Sustainability Citizens, or Society
or Global Governance?

• Individual citizen/consumer actions can solve 5
  of problem. (But useful contribution, and good
  for engagement.)
• Large-scale (global) environmental changes need
  large-scale (governmental) policy changes
• We need a Cultural Transformation (Third
  Industrial Revolution Sustainability
  Transition)
• Global climate/envtl changes arise from systemic
  market failures. Governments role is to remedy
  these (Adam Smith also recognised that!) ..
  
• mutually-agreed mutual coercion