Transcript Children`s_environmental_health_climate-change

Climate Change
and Health
With special reference to
risks facing small islandstates
Anthony
J McMichael
National Centre for Epidemiology & Population Health
The Australian National University
Canberra, ACT 0200
Climate Change: the “debate”
Skepticism is now receding. We know that:
• Greenhouse gas (GHG) concentrations are
increasing
• GHGs affect the climate system (thankfully!)
• World average temperature has risen relatively
fast over the past 30 years
• Sea-level rise is gradually accelerating
• Many temperature-sensitive systems/processes
have changed over the past two decades
Kilimanjaro 1970
Area (km2)
Ice on Kilimanjaro
15
10
5
0
1900 1920 1940 1960 1980 2000 2020
Year
Kilimanjaro 2000
Climate Change: Basic Issues
• Earth’s climate varies naturally – because of a variety
of cosmological and geological processes.
• “Climate change” refers to an additional, and
relatively rapid, change induced by human actions.
• The additional change – several degrees C within a
century – will disrupt the foundations of life on Earth.
• Ecosystems and life in general have evolved within a
narrow band of climatic-environmental conditions.
1.4
Number of Earths
used by humanity
Number of Earths
1.2
1.0
One Earth is available
(The planet’s total biocapacity = 1.0)
0.8
0.6
0.4
0.2
0.0
1960s
1970s
1980s
1990s
Based on Wackernagel et al, 2002
Changes in environmental indicators, 1750 - 2000
Atmos CO2 conc
Atmos ozone loss
Atmos N2O conc
Atmos CH4 conc
Av surface temp (NH) Climate disasters
Fully exploited fisheries
Loss of trop forest, woodland
Coastal shrimp farms
Coastal N2 flux
Domesticated land Global biodiversity
From: Steffen et al. In press 2004
20
This presents a rate-of-change
IPCC
estimates
problem
for (2001)
many natural
oC increase
a
1.4-5.8
systems/processes
Average Global
19
Temperature
(OC)
High
18
17
16
Central estimate = 2.5 oC
(plus increased variability)
Low
15
14
Band of historical
climatic variability
13
1860
1900
1950
2000
Year
2050
2100
Sea-level
rise
over
coming
centuries
Sea-Level Rise, over the coming millennium
following 70 years of excess greenhouse gas emissions
Sea-level rise (m)
1.5
Total sea level rise
1.0
Ocean Expansion
Ice-melt
0.5
Greenhouse gas emissions (“super-Kyoto” action)
0.0
Peaking in 2050
200
400
Time from start (years)
600
800
IPCC,
IPCC
20012001
SLR Risks to Small
Island-States
•
•
•
•
Coastal flooding
Amplified storm surges
Damaged coastal infrastructure (roads, etc.)
Salination of island fresh-water (esp.
subterranean cells)
• Impaired crop production
• Population displacement: diverse health
risks (nutrition, infection, mental health)
Modulating
influences
Health
Healtheffects
Effects
Temperature-related
Temperature
-related
illness and death
Extreme weatherExtreme
weatherrelated (floods,
storms,
related
health
effects
etc.) health effects
Human
exposures
Climate
Change
Air pollution-related
health effects
Regional weather
changes
Microbial
changes:
Contamination
pathways
Contamination paths
•Heat waves
•Extreme weather
•Temperature
••Precipitation
Transmission
Transmission dynamics
dynamics
•Sea-level rise
Water
Water and
and food-borne
food-borne
diseases
diseases
Vector
Vector -borne
borne and
and
rodent
borne
rodent borne diseases
diseases
Changes in agroecosystems, hydrology
Effects of food and
water shortages
Socioeconomic and
demographic disruption
Mental, nutritional,
infectious-disease and
other effects
ENSO and
climate change
• The effect of global climate change on the future
frequency and/or amplitude of El Niño is uncertain .
• Events may become more frequent or more intense.
• However, even with little change in amplitude,
climate change is likely to lead to greater extremes of
drying and heavy rainfall, and to increase the risk of
droughts and floods that occur with El Niño
[IPCC 2001].
VECTOR-BORNE DISEASE
Estimated population at risk of dengue fever under
“standard” climate change scenario: 1990, 2085
1990
2085
.
Source. Hales S et al. Lancet (online) 6 August 2002. http://image.thelancet.com/extras/01art11175web.pdf
Modelling Malaria Transmissibility in Zimbabwe. I
Baseline 2000
Courtesy: Kris Ebi
Modelling Malaria Transmissibility in Zimbabwe. II
Baseline 2000 2025
Courtesy: Kris Ebi
Modelling Malaria Transmissibility in Zimbabwe. III
Baseline 2000 2025 2050
Courtesy: Kris Ebi
What Should Health Ministries Do?
• Commission/conduct national assessments of
risks to health from CC (and SLR)
• Participate in emergency management
preparedness (communications, facilities, skills)
• Argue the centrality of population health as the
real “bottom line” in the sustainability debate
• Make links with other ministries – education,
primary industry (agriculture), fisheries,
development planning, etc.
• Highlight the sense and cost-savings of
adaptation strategies, to lessen adverse impacts
That’
s All
Global average temperature (oC) over the past millennium
GHG: Coming Decades
The International Energy Agency predicts that the
increase in greenhouse gas emissions from 2000 to
2030 in China alone will almost equal the increase from
the entire industrialized world.
China is the world's second largest emitter of such
gases, after the United States – even though China's
per-person emissions are, for example, still only oneeighth of those in the United States.
Population
Total real GDP
Damming of rivers
Water use
Urban population
Motor vehicles
Foreign direct
investment
Fertiliser consumption
MacDonalds Restaurants
International tourism
From: Steffen et al. 2003
Need to convert estimates of regional
food yields into estimates of changes in
numbers of malnourished people
Climate change impacts on rain-fed
cereal production, 2080
(IIASA: Fischer et al, 2001)
Dengue Fever: Estimated geographic
region suitable for maintenance of Ae.
aegypti, alternative climate scenarios
for 2050
.
Darwin
.
.
.
Port Headland
Katherine
.
.
Townsville
Port Headland
..
Cairns
Mackay
Scenario: A1B (mid) CSIROMK2
.
Rockhampton
.
Brisbane
.
.
Darwin
Katherine
.
Broome
.
Port Headland
.
.
.
Cairns
Townsville
.
Mackay
.
Rockhampton
Carnarvon
Scenario: A1F1 (high) CSIROMK2
NCEPH/CSIRO/BoM, 2003
.
Rockhampton
Carnarvon
Mackay
Model Estimate: Current
Dengue Risk Region
.
.
Townsville
.
.
.
Cairns
Broome
Katherine
Broome
.
.
Darwin
Categories of climate
extremes
• Simple extremes based directly on climate
statistics
– Hot day = day with temperature > 95th centile
• Complex, event-driven extremes
– Droughts
– Floods
– Hurricanes/typhoons/tropical cyclones
Changes in climatic
phenomenon
Confidence in
observed changes
(latter half of 1900s)
Higher maximum temperatures
- more hot days
Probability of
projected changes
to 2100
Likely
Very likely
Very likely
Very likely
Likely
Very likely
Likely,
(N mid to high
latitudes)
Very likely
Increased summer continental drying
and associated risk of drought
Likely, in a few areas
Likely, over most midlatitude
continental
interiors.
Increase in tropical cyclone peak wind
intensities
Not observed in the
few analysis
available
Likely, over some
areas
Increase in tropical cyclone mean and
peak precipitation intensities
Insufficient data
Likely, over some
areas
Higher minimum temperatures,
- fewer cold days and frost days
Increase of heat index over land areas
More intense precipitation events
IPCC WORKING GROUP I, Third Assessment Report, 2001