Download (natural & `unnatural`) … Past and Future Risks to Health

Climate Change (natural & ‘unnatural’)
… Past and Future Risks to Health
A.J. McMichael
National Centre for Epidemiology and Population Health
The Australian National University
Canberra, Australia
CONVENTIONAL FRAME FOR
‘SOCIAL DETERMINANTS OF
HEALTH’
Social norms, ideology,
knowledge; socioeconomic equity
History
Marketing,
social norms
Production and
processing systems:
Human
culture
Built
environment
(cities, suburbs,
roads, etc.
Managed
biophysical
environment
Mis-managed;
excess demands
Environmentally
Sustainable
Physico-chemical
contaminants
Nonsustainable
Overload of natural
environmental
systems
Individual
health risks
e.g. air pollution,
contaminated food &
water, agro-industrial
effluent, endemic
infections, social contact
patterns,
food, ‘substance’ items,
cars, appliances, clothes
Energy
inputs
Natural
biophysical
environment
Human
behaviours
Sexual
activity
Food
choices
Alcohol &
smoking
Physical
activity
Road-use
e.g. less (and
nutrient-poor) food;
water shortage;
altered infectious
disease patterns,
morale & mental
health disorders
Social conditions
and relations
(Remediable) local
environmental
pollution
Global
environmental
change/disruption
(climate change,
ozone depletion, soil
loss, water depletion,
biodiversity loss, etc.)
Communitylevel
health risks
Population
health
risks
Australian Govt’s
Climate Commission
Report on “Climate
Change and Health”
Public launch in
Sydney, Nov 28, 2012.
First of the climate
change impact reports,
to be prepared by the
Commission.
Variations in Average Northern Hemisphere Temperature, oC
Rel. to 1960-80; Multiple palaeo-climatic sources, averaged
+4
Modelled
temperature
projection to
2100 – plus
3-4oC (?)
Temperature variation around the
smoothed graph, at half-decade
scale, is approx. plus/minus 0.5oC
+3
Average Temp, oC
(rel. to 1960-80)
+2
Holocene Climate
+1
Holocene Climatic
Optimum, I & II
+0.5
0
Cooling
event
-0.5
Sahara
dries out
-1
-2
Accelerated
warming
since 1975
Roman
Warm
Period
Mediaeval
Warm
Period,
Europe
Drought in
Eastern
Mediterranean
region
17th Cent
Crisis,
Europe
Little Ice Age in
Europe (similar
in China)
Post-glacial
warming, (after
transient rapid
cooling due to
Younger Dryas)
Tambora
eruption
1815
536 CE Event
(acute cooling)
2-3oC fall
-3
-411 10 9 8 7 6 5 4 3 2 1 0 2 4 6 8 10 12 14 16 18 20 22
Millennia BCE
2000 yrs ago
Centuries CE
“A Safe Operating Space for Humanity”
Identifying & quantifying planetary boundaries that should not be transgressed
Rockstrom et al.
Nature 2009
Green = estimated
safe operating space
Climate change
Biodiversity
loss
Nitrogen
cycle
Global Annual Temperature, 1750-2010: The Rising Atmospheric CO2
Concentration, plus Sporadic Volcanic Cooling, Provides the Best
Modelled Fit of the Actual Observed Temperature Trend
Expected temp
trend – modelled –
due to increasing
Actual annual
CO2 concentration,
temperatures
punctuated by
sporadic volcanic
cooling
Post-1950s rise, mostly
attributable to human
actions (IPCC)
+1.5oC
1750-2010
Systematic
thermometer use
begins
BEST Project, UC Berkeley, 2012
Regional Temperature Change over Past ~20 Years
+4oC
+3oC
+1.5oC
+2oC
+2.5oC
-0.5oC
+1oC
+2oC
+1.5oC
-1.5oC
+1oC
+1oC
+1oC
La Niña (ENSO):
westward flow of
cold surface
water: warm water
heaps up in
western Pacific
-1oC
+1oC
-1.5oC
Difference from 1980-2010 average temperature
-4oC
0
+4oC
Adapted from: US Nat Oceanic &
Atmospheric Admin (NOAA), State
of Climate, 2011
Arctic Sea Ice Extent (millions km2), Sept 17, 20
Median
ice limit
1979-2000
Nth Pole
UK
± 2 standard
deviations
Atlantic Ocean
1979-2000
average
2007
2012
Source: National Snow
and Ice Data Center,
Boulder, Colorado
Annual Temperature Fluctuations in Western (alpine)
Europe and Scandinavia, 450-650 CE:
Evidence of abrupt cooling in 536-545 CE
2
0
-2
460
480
580
520
540
560
580
600
620
640
NOTE: temperature data are from seven different regional tree-ring datasets. The data are de-trended over time, and the mean is set at zero.
Temperature graph from: Larsen LB et al. (2008).
Geophys. Res. Lett., 35, L04708.
doi:10.1029/2007GL032450.
Constantinople
Ephesus
40ON
Alexandria
O
30 N
Aksum’s main
trade routes,
land and sea
during 300700 CE.
Jerusalem
EGYPT Clysma
Thebes
Arabian
Peninsula
Berenice
Sahara
Mecca
20ON
NUBIA
(KUSH)
Meroë
Red
Sea
Adulis
Aden
Aksum
10ON
To
African
interior
0ON
30OE
Arabian
Sea
AKSUM Zeila
Indian
Ocean
40OE
Great Lakes
50OE
(
red
lines/arrows)
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
1644
European
Temperature
Variation
standardised units
Famine-yrs/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
Climate Change and Human Health:
Types of Health Risk Assessment
(past, present, future)
Temperature
Statistical study:
Estimating the
attributable burden
of disease
Scenario-based modelling:
Estimating the range of
future plausible risks
+2.0oC
+1.5oC
Empirical Studies:
Risk per oC
Empirical Observations:
Attributable to climate
change?
1950
Natural
temperature
variation
2050
Now
Modelled future
temperature(s)
Climate Change
temperature
~
Mean climatic conditions
and rainfall
Other global/systemic
environmental changes
– coexisting with climate
change
Glacier Altered
loss, sea- surface
level rise water
Reduced
food yields
Ecosystem Property
damage
loss
Food
prices,
choices
Altered
microbial
ecology
(host-animals,
vectors, pathogen
Community &
multiplication)
Household hygiene
family morale:
Nutrition: mental health
Local food yield
child devt;
problems
adult health
shortages,
prices:
competition
Conflicts,
displacement
InfraTourism
structure
and
damage recreation
Physical
hazards
Loss of jobs, Direct
livelihoods economic
impacts
River flows,
Freshwater
availability
and Variability
People
Relocation
heatwaves,
extreme
weather
events
Infectious
disease risks
Direct impacts of
heat:
physiological,
organ damage,
behavioural
Risk of injury
and death
Post-event
depression, etc.
Deaths Attributable to Climate Change: Year 2000
Estimated annual deaths due to climate change from: malnutrition
(~80K), diarrhoea (~50K), malaria (~20K), flooding (~3K)
14 WHO statistical regions scaled by estimated annual mortality (in 2000)
due to change in climate since c.1970. Selected major causes of death.
(Patz, Gibbs et al, 2007: based on McMichael, Campbell-Lendrum, et al, 2004)
Climate Change Influences
on Health in Australia
Already apparent: preexisting risks amplified by climate change
Uptrend in av annual no. of heat-days  deaths, hospitalisations
Increase in no./severity bushfires  injury/death, resp. hazard, mental hlth
Probable ongoing health impacts: but not yet clearly identified
Rise in some food-borne diarrhoeal diseases
Altered air quality: ozone formation, aeroallergens
Mental health impacts, esp. in some (drying) rural regions: e.g. MD Basin
Predicted future health impacts
Extreme weather events: trauma, infectious disease, depression
Water shortages: affecting food yields, domestic hygiene
Shifts in mosquito-borne infection patterns:
Dengue, Ross River virus (& chikungunya?), Barmah Forest virus,
Japanese encephalitis, etc.
Thermal stress in outdoor workers: accidents/injuries, organ damage
Typical Relationship of Daily Temperature to
Daily Death Rate in Temperate-Zone Countries
High
High
Daily
Daily
death
rate
Death
Rate
Comfort
‘Comfort
zone’
zone
Low
Low
5
Source: McMichael, 2012
Relative Risk
of (daily)
Death
Source: Huang, Barnett et al, 2012
10
15
20
25
30
35
oC
Daily temperature,
Daily
Temperature (oC)
Brisbane
Melbourne
24oC
22oC
Daily Temperature (oC)
40
Evidence of a Warming Australia
Bureau of Meteorology: '2009 will be remembered for extreme bushfires, dust-storms, lingering
rainfall deficiencies, areas of flooding and record-breaking heatwaves.'
Australia’s 2009-2010 mean temperature was ~1°C above the 1961-90 average.
2010
Decadal mean temperature
1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Heatwaves, Illness Events, Mortality
Melbourne, Australia, 2009
Temperatures
Ambulance call-outs for heat-related illnesses
in Metropolitan Melbourne, 19 Jan - 1 Feb, 2009
27-31 January 2009: max
temperatures 12-15°C
above summer norm.
250
28-30 Jan: > 43°C
Number of
ambulance
call-outs
50
45
200
40
Maximum
Temperature
35
30
150
25
Heat Stress
100
20
15
Dehydration
50
January 29-30:
Great increase in
ambulance call-outs
126 out-of-hospital deaths
(vs. 44 expected deaths)
10
Heat Stroke
Call-outs, deaths
Temp
oC
5
0
Jan: 19
0
20
21
22
23 24
25
26
27
28 29
30
31 1 Feb
Date
SOURCE: January 2009 Heatwave in Victoria: an
Assessment of Health Impacts. State of Victoria 2009
Relationship of Salmonella gastro-enteritis
occurrence to daily temperature, Sydney, 1990-2010
Relative
Risk
As maximum daily temperature
increases, the risk increase with
min. daily temperature steepens
[26oC]
[22oC]
[19oC]
Minimum Daily Temperature oC
Source: Ainslie Butler, NCEPH/ANU, unpub
Dengue Fever: Estimated ‘receptive’ region for
Ae. aegypti mosquito vector, under alternative
climate-change scenarios for 2050
Darwin
.
.
Katherine
Darwin
.
.
.
Katherine
.
.
Broome
Port Hedland
.
Townsville
Port Hedland
..
Current risk region for
dengue transmission
.
Mackay
.
Risk region for medium Rockhampton
Carnarvon
emissions scenario, 2050
.
Cairns
Townsville
.
.
.
Cairns
Broome
Mackay
.
Rockhampton
Darwin
.
Brisbane
.
.
Katherine
.
Broome
.
Port Hedland
.
.
Cairns
Townsville
.
.
Mackay
Rockhampton
Risk
region
for
high
Carnarvon
emissions scenario, 2050
.
NCEPH/CSIRO/BoM/UnivOtago, 2003
Climate Change and Malaria
Potential transmission in Zimbabwe
Baseline 2000 2025 2050
Climate suitability:*
red = high; blue/green = low
Harare
Low probability
Highlands
Medium probability
High probability
Bulawayo
* Temperature + minimum seasonal rainfall
Ebi et al., 2005
Climate Change and Malaria
Potential transmission in Zimbabwe
Baseline 2000 2025 2050
Climate suitability:
red = high; blue/green = low
Harare
Bulawayo
Ebi et al., 2005
CLIMATE CHANGE: Poor Countries Projected to Fare Worst
MODELLED CHANGES IN CEREAL GRAIN YIELDS, TO 2050
20
Plus climate-related:
• Flood/storm/fire damage
• Droughts – range, severity
• Pests (climate-sensitive)
• Infectious diseases (ditto)
36
80
64
Percentage change in yields to 2050
-50
-20
0
+20
+50
+100
UN Devt Program, 2009
Now
Skipjack tuna,
Pacific Ocean
2050
2050 A2
1,727,000 m tonnes/yr
2100
432,000 mt
Loukos H, Monfray P, Bopp L, Lehodey P. (2003)
Potential changes in skipjack tuna habitat from a
global warming scenario: modeling approach
and preliminary results. Fisheries
Oceanography, 12(4): 474-482
2100 A2
Source: P. Lehodey
Adaptation and Mitigation
Adaptation: Risk management
Time-frame Options:
- Immediate protection (heatwave warnings, dams/sea-walls)
- Long-term protection (urban design/greening, resilient rural communities, vaccines)
Priority/equity (who is vulnerable?)
Evaluate (cost-effectiveness?)
Mitigation … and its Health Co-Benefits to local population
- Cleaner urban air: ↓cardio-resp disease
CH4
- More walking/cycling:  fitness, social contact
- Healthier climate-proof insulated housing
- Diet: local fresh foods
less (ruminant*) red meat  ↓obesity,
cardiovasc disease, some cancers
* cattle, sheep, goats, camels, buffaloes
Brrrp
Three Key Messages
1. Human-induced ‘climate change’ is real, increasing
… and quite distinct from ‘local envtl pollutants’ in
the type, range and significance of health impacts
2. Health professionals will, increasingly, encounter
changing rates of differential diagnoses, emergency
hopital admissions, enquiries from concerned public
3. Health sector will need to adapt (continuously) by:
------
Understanding climate-related exposures and risks
Curbing the sector’s greenhouse emissions
Upgrading/changing community surveillance practices
Working more closely with other sectors
Assisting with public education, and political advocacy
That’s
All
“… between 5-30% of the decrease in sea ice is
due to the Atlantic Multi-decadal Oscillation
…[which] implies that 70-95% of the changes
are caused by human-induced global change."
40
Total Arctic Sea-Ice
Volume (1000 km2)
JJ Day, Univ. of Reading, July 2012
30
1979-2011 average
20
(av.1979-2011)
10
(2012)
Adapted from: Polar
Science Center (Univ.
Washington), 2012
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Estimated age-standardised incidence rate per 100,000
Melanoma of skin, both sexes, all ages
≤0.4
30oN
≤ 40
< 0.4
< 0.8
< 1.6
< 3.9
30oS
< 36.7
Source: IARC, 2008. Globocan http://globocan.iarc.fr, accessed on 20/08/2012