Part 2 - Climate Change and Human Population Health

Report
Climate Change and Human Population
Health: Past, Present, Future
Department of Defence, June 2013
Tony McMichael, AO
Emeritus Professor (Population Health)
National Centre for Epidemiology and Population Health
The Australian National University
[email protected]
Deaths Attributable to Climate Change: Year 2000
Estimated annual deaths attributable to climate change from:
malnutrition (~80K), diarrhoea (~50K), malaria (~20K), flooding (~3K)
14 WHO statistical regions scaled by estimated annual mortality (selected causes, in
2000) due to change in climate during 1970-2000.
(Patz et al, 2007: based on McMichael, et al, 2004)
Climate Change: Health Impact Pathways
Physical
systems
Economic/social
impacts:
(river flow, vegetation,
soils, ocean temp, etc.)
Climate
Change:
Impacts
Direct (‘primary’)
impacts (extreme
weather, heatwaves,
air pollution)
Biological &
ecological
processes
Human Health
infrastructure, economic
productivity, jobs, coastal
displacement, resourcerelated conflict/warfare
Indirect (‘secondary’)
impacts, ecologicallymediated: changes in
food, water, mosquitoes
• Injuries/deaths; mental stress
• Thermal stress impacts
• Infectious diseases
• Under-nutrition
• Mental stresses
• Trauma/deaths
Indirect (‘tertiary’)
health impacts –
socially & politically
mediated
Dry
Normal Range
Wet
5-year running mean
yield deviation
Spring
Barley Yield
(deviation, %)
Rainfall Index, April-June
Relationship between Rainfall Index (combines rainfall
and temperature) in Spring (April-June) and Barley Yields
in Czech Republic since 1940s.
Brazdil et al, 2008
CLIMATE CHANGE to 2050: MODELLED CHANGES IN
CEREAL GRAIN YIELDS (due to temperature and soil moisture)
Poor Countries are Projected to Fare Worst
20
36
Not including climate-related:
• Flood/storm/fire damage
• Droughts – range, severity
• Pests (climate-sensitive)
• Infectious diseases (ditto)
80
64
Percentage change in yields to 2050
-50
-20
0
+20
+50
+100
UN Devt Prog, 2009
Climate Change: Diverse Influence Paths on Infectious Diseases
eg. dengue,
malaria;
Ross River virus,
Lyme disease
eg. nutritionrelated immune
function
Social-demographic influences
Dengue Fever: Estimated
‘receptive’ region for Ae. aegypti
mosquito vector, under
alternative climate-change
scenarios for 2050
Darwin
.
.
Katherine
.
.
Katherine
.
.
Broome
Port Hedland
Current risk region for
dengue transmission
.
Townsville
Port Hedland
..
.
Mackay
Risk region for medium
Carnarvon
emissions scenario, 2050
.
Cairns
Townsville
.
.
.
Cairns
Broome
Rockhampton
Mackay
.
Rockhampton
Darwin
.
Brisbane
.
.
Katherine
.
Broome
.
Port Hedland
.
.
Cairns
Townsville
Risk region for high
Carnarvon
emissions scenario, 2050
.
NCEPH/CSIRO/BoM/UnivOtago, 2003
.
.
Mackay
.
Rockhampton
Climate Change Influences on
Health in Australia
Already apparent: baseline risks amplified by underlying climate change
Uptrend in av annual no. of heat-days  deaths, hospitalisations
Increases in no./severity bushfires  injury/death, resp. hazard, mental health
Severe flooding (due to increased sea-surface temp, increased rainfall?)
Probable current health impacts: but not yet clearly identified
Rising rates of some food-borne enteritis (diarrhoeal) diseases
Altered (urban) air quality: ozone formation, aeroallergens
Mental health impacts, esp. in some (drying) rural regions: e.g. MD Basin
Predicted future health impacts
More extreme weather events  trauma/deaths, infectious disease, depression
Water shortages, affecting food yields, domestic hygiene
Mosquito-borne infections – shifts in range and seasonality:
Dengue, Ross River virus, Barmah Forest virus, Japanese encephalitis, etc.
Increased thermal stress at work, esp. in outdoor workers and under-ventilated
factories: accidents/injuries, organ damage; reduced work capacity
Changes in Average Northern Hemisphere
Temperature over the Past 11,000 Years
AJ McMichael, 2012)
Modelled range of
projected global
temperature rise to 2100
(vs.1990) = + 2-5oC
+4
Variations in NH Temp, oC
(rel. to Holocene average)
+3
Holocene
+2
Holocene
Climatic
Optimum I, II
+1
0
Sahara
dries
-1
-2
Post-glacial warming
following Younger Dryas
cooling, 12.8-11.6K BP
Roman
Warm
Period
Mediaeval
Warm Period,
Europe
Drought & cooling in
East Mediterranean
region
Faster
warming
since 1975
Little Ice Age:
Europe, China
Early agrarian
societies begin to
form: Egypt, Sumer,
southern China
Acute cooling:
Tambora
eruption 1815
Acute cooling:
536 CE ‘Event’
-3
11 10 9 8 7 6 5 4 3 2 1 0 2 4 6 8 10 12 14 16 18 20 22
Millennia BCE (1000s of yrs)
BCE/CE
Centuries CE (100s of yrs)
Europe’s coldest period, 1570-1660, during Little Ice Age
Food yields down, grain prices tripled … conflict , war, displacement
Cold Period
1570-1660
Nth Hemisphere
Temperature
Variation
oC
European
Temperature
Variation
standardised units
Famine-years/decade x 2
Epidemic rate x 3
Adult height ↓1.5cm
Rate of
Migrations,
Europe
War
Fatality
Index,
Europe
1500 1550 1600 1650 1700 1750 1800
Zhang et al., PNAS, 2011
Temperature, Conflict, Warfare within China, 1000-1940:
Relationship to Fall of Dynasties
Five (grey) periods of cold in China
Northern (> 20oN)
Hemisphere
temperature
variations, o C
( cf 1961- 90 av.)
The ‘Little Ice Age’
1000
1200
1400
1600
1800
2000
Wars
Rebellions
No. of internal
wars (per
decade)
N. Song S. Song Yuan
Ming
Qing
Population size
(millions)
1000
Adapted from Zhang et al, 2009
1200
1400
1600
1800
2000
Civil Conflicts, 1950-2004, in Countries Affected or Not/Little Affected by ENSO
Affected
(n= 93 countries)
(n= 82 countries)
Annual
Civil
Conflict
Rate
Probability of new civil
conflicts breaking out
in El Niño years is
double that seen in
cooler La Niña years
(% of
countries
embroiled)
Weaker
El Niño Index (NINO3: May-Dec
average Sea-Surface Temperature)
Hsiang et al., Nature 2011
Stronger
Now, over to Colin Butler ………

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