Download Effects of climate change on infectious diseases

CIS oƒ HDGC
Carnegie Mellon
Effects of climate change on
infectious diseases
Hadi
Dowlatabadi
Funded
BY:
My
Thanks
to:
Science
Foundation,
Center National
for Integrated
Study
the Human Dimensions
of
Elizabeth
Casman,
IlyaofFischhoff,
Baruch
GlobalUSDOE,
Change,
Carnegie
Mellon
University,
&
ExxonMobil,
Fischhoff,
Lester
lave,
Emilio
Moran,
EPRI, NOAA,
USEPA,
and
University
Fellow,
Resources
theAPI
Future
Richard
Tol,for
Duane Gubler &
the organizers of the conference
Outline of this talk
2
Background on climate
and disease
Climate & politics of
disease
What is climate
change?
Projecting malaria &
climate change
Other determinants of
disease
Challenges ahead
CIS oƒ HDGC
Carnegie Mellon
Climate determines the conditions
permissive of infectious diseases
• For vector borne diseases this would be the conditions
suitable for mutual development of the vector and
pathogen.
• Climate conditions can determine whether the pathogen
and humans come into contact with one another by
affecting human behaviour and pathogen ecology.
• Extreme climate events can overwhelm waste water
management infrastructures.
• Adverse climate conditions can affect food production,
lead to hunger and hence immune suppression.
• …
3
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Carnegie Mellon
How important is climate change?
• Climate change can overwhelm the adaptive capacity
of human-habitat interactions, especially where there
is little access to resources and technology.
• Climate change is important to health in affecting:
» Ecology of managed and unmanaged systems.
» Patterns of human activity and movement.
» Frequency of extreme events.
» Changes in atmospheric chemistry.
• The key question is whether climate change is
important vis-à-vis other global change processes.
4
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Many fear climate change will
spread tropical diseases like Malaria
5
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Carnegie Mellon
Outline of this talk
6
Background on climate
and disease
Climate & politics of
disease
What is climate
change?
Projecting malaria &
climate change
Other determinants of
disease
Challenges ahead
CIS oƒ HDGC
Carnegie Mellon
What is climate change?
• The idea is that we have changed the surface of the
earth, and its atmosphere to such an extent that:
» Incoming solar radiation is bounced back into space
differently, with more energy staying in the atmosphere.
» This will affect the flow of energy & water between land,
atmosphere and oceans.
» Changing patterns of temperatures, clouds and precipitation.
• We bring about climate change through: burning fossil
fuels, agriculture, draining wetlands, building dams,
cutting down trees and paving over paradise...
7
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Monthly temperatures for Pittsburgh
1871-1993
8
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Monthly precipitation for Pittsburgh
1871-1993
9
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Change in annual average temperature
1871-1993
TSP & SO2
SO2
CAA/OPEC
2.5°C
10
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Trends in mean monthly temperature
11
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Change in total annual precipitation
1871-1993
12
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Change in total annual precipitation
1871-1993
13
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Carnegie Mellon
Outline of this talk
14
Background on climate
and disease
Climate & politics of
disease
What is climate
change?
Projecting malaria &
climate change
Other determinants of
disease
Challenges ahead
CIS oƒ HDGC
Carnegie Mellon
Other global change phenomena which
can impact prevalence of infectious
diseases
• Prosperity.
• Demographics.
• Movement of people and goods.
• Immunity status.
• Land use and cover.
• Knowledge & technology.
• Social norms.
• Security.
15
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Economic Prosperity
• The US has seen sustained growth in the overall
economic prosperity of its population over the past
century averaging more than 2% p.a.
• There has been miraculous growth in Far Eastern
countries, at times 3 to 4 times faster than the US,
but these miracles have recently floundered.
• Meanwhile, there has not been any improvement in
living conditions of a large fraction of the world’s
population.
16
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Carnegie Mellon
Population
• Population growth rates are falling.
• The earth’s population is not expected to exceed 12
billion by 2100.
• Populations are expected to grow significantly older,
from ~ 5% over 60 today to ~20% over 60 in 2100.
• Urban and peri-urban populations are growing rapidly,
especially in less prosperous and lower-middle income
countries.
17
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Comparing Under 5 mortality rates:
Urban/Rural by income class
1.6
1.4
1.2
1
0.8
0.6
0.4
Philippines
19
India
Brazil
Q1
Q2
Nigeria
Uganda
Q3
Q5
Q4
Kenya
Pakistan
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Forced migrations
8
• Internally displaced
populations and
international refugees
rarely have access to
health services & can
be potent vectors.
• Their rate in (#/1000)
has grown 50% over
the past 30 years.
7
6
5
4
3
2
1
0
1965
1975
IDP
20
Source: CIPEC
REF
1985
1995
World Pop
2005
Total Disp
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Immunity status
1000
• Over 500M are
malnourished, but their
rate and numbers have
been falling.
• Over 35M are HIV
positive, but their rate
and numbers have been
rising
800
600
400
200
0
1960
1980
Malnourished
21
Sources: FAO and WHO
2000
2020
HIV +
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Where & When?
Indiana ~1820 cf. ~1990
Forest
Wetland
Prairie
Water
Row Crop
Pasture/Grassland
Urban
22 Courtesy of the Center for the Study of Institutions, Population and Environmental Change, Indiana University, Bloomington
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Deforestation along the TransAmazon
Highway: from before 1970 through 1991
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23 Courtesy of the Anthropological Center for Training and Research on Global Environmental Change, Indiana University, Bloomington
Carnegie Mellon
Knowledge and technology
• Genetic engineering
• Designer pharmacology
• Remote sensing
• Diagnostics on a chip
• But few, if any, of these
innovations are within
reach of and address the
needs of the poorest
nations.
Source: Nature 1997
24
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Carnegie Mellon
Social norms
• All syntheses on how to succeed in combating
infectious disease draw attention to the importance
of the following factors:
» Equity.
» Political resolve to provide public health.
» Synergy of intervention with other social goals.
25
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Security
• Extreme natural events and absence of services can
lead to:
» Internal displacements,
» International refugees, and
» Hunger
• More often though, these are caused by war and
social discord.
26
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Global change is about multiple
interaction paths
Local
Ecology
Famine
Climate
change
Population
War
Infectious
disease
Immune
status
Prosperity
Knowledge
Mobility
27
Social
Norms
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Climate change, extreme events and
Cryptosporidiosis
day 1 day 2 day 3 day 4 day 5 day 6 week 2 year 2 year 20
Climate
change
Torrential
rain
Overwhelm
s sewage
system
Reconside
r land use
patterns
28
Revise
sewage
handling
Detection
in water
Boil water
advisory
Detection
in patients
Cryptoin water
supply
Indirect
alert
Epidemic
Understand
what
happened
R&D for
better
detection
CIS oƒ HDGC
Carnegie Mellon
Outline of this talk
29
Background on climate
and disease
Climate & politics of
disease
What is climate
change?
Projecting malaria &
climate change
Other determinants of
disease
Challenges ahead
CIS oƒ HDGC
Carnegie Mellon
Climate determines the potential range of vectors
but public health determines disease outbreaks
30
Source: WHO
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Reported cases of Dengue 1980-96:
Does climate change abruptly at the border?
31
Source: US National Assessment
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Life expectancy is a political map
not a climatic one
32
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Life expectancy & GDP
80
y = 4.2Ln(x) + 34.9
R2 = 0.8
60
40
20
0
0
34
Africa
Asia-CP
10000
America
Europe
20000
America-CP
Europe-CP
30000
ANZ
Log. (Asia)
40000
Asia
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Carnegie Mellon
Disruption of health services can be
disastrous, but easily recoverable
Diphtheria Cases (x1000) in SU & FSU
60
50
40
30
20
10
0
1965
35
1970
1975
1980
1985
1990
1995
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Carnegie Mellon
Disruption of health services can be disastrous,
and evolve into a long-term nightmare
Malaria Incidence in Newly Independent States
40,000
30,000
20,000
10,000
0
1990
36
Source: WHO
1991
1992
1993
1994
1995
1996
1997
CIS oƒ HDGC
Carnegie Mellon
Outline of this talk
37
Background on climate
and disease
Climate & politics of
disease
What is climate
change?
Projecting malaria &
climate change
Other determinants of
disease
Challenges ahead
CIS oƒ HDGC
Carnegie Mellon
Revisiting malaria & climate change
predictions (x1000 excess deaths)
800
600
400
200
0
2000
2020
Climate Change
38
Source: Tol & Dowlatabadi (2000)
2040
2060
+Population Growth
2080
2100
+Economic Growth
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Challenges in projecting future conditions
• Today’s climate-malaria prevalence models are
calibrated to regions with endemic malaria. These are
not suitable for assessment of the malaria transition
other regions.
• Will there be far-reaching technological advances?
• Where people prosper will they devote resources to
fighting malaria?
• Where malaria is the social norm, how might it become
socially compatible to fight it? What about the
reverse?.
39
CIS oƒ HDGC
Carnegie Mellon
Outline of this talk
40
Background on climate
and disease
Climate & politics of
disease
What is climate
change?
Projecting malaria &
climate change
Other determinants of
disease
Challenges ahead
CIS oƒ HDGC
Carnegie Mellon
Projections of global change are
fraught with uncertainty
• We have trouble projecting socio-economic changes.
HIV-AIDS,
fall of the Soviet Block, miracle and faltering of the Asian Tigers.
• We have trouble projecting how the climate system
will react to human induced changes?
H2O, H2O, H2O, H2O, H2O, H2O, H2O,
H2O, H2O, H2O, H2O, H2O, H2O, H2O,
H2O, H2O, H2O, H2O, H2O, H2O, H2O,
H2O, H2O, H2O, H2O, H2O, H2O, H2O,
H2O, H2O, H2O, H2O, H2O, H2O, H2O,
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H2O, H2O, H2O, H2O, H2O, H2O, H2O,
CO2, CO2, CO2, CO2, CO2, CO2, CO2,
41
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CO 2, CO2, CO2, N2O, N2O, O3, O3, CFCs, All else.
CIS oƒ HDGC
Carnegie Mellon
Summary
42
•
Climate change can impact health outcomes through many
pathways.
•
Nevertheless, demographic, socio-economic, technological and
political factors are more important than climate in public
health outcomes over the next century.
•
Non-climate factors change more rapidly and are generally
easier to manipulate than the climate system.
•
A poorly designed climate policy will do more harm than good.
•
We are ill equipped to address key global public health
challenges in the years ahead.
CIS oƒ HDGC
Carnegie Mellon