A.J. McMichael National Centre for Epidemiology and Population Health The Australian National University Canberra, Australia Climate Change and Human Health.

A.J. McMichael

National Centre for Epidemiology and Population Health The Australian National University

Canberra, Australia

Climate Change and Human Health

A wide-scope overview

Glacier loss, sea-level rise

Nutrition: child devt,

adult health

Ecosystem damage

Property loss

Infra-structure damage

Reduced food yields

Tourism and

recreation

Altered surface water

Loss of jobs,

livelihoods

Direct economic impacts

Climate changeMean conditions

and Variability

Physical hazards

Fresh-water

availability

Food prices, choices

Community morale:

mental health disorders

temperature and rainfall

Microbial ecology(host-animals,

vectors, pathogens)

Hygiene; local food yield

River flows, dams

Infectious disease risks Post-event

depression, etc.

~Other systemic environmental changes – acting in concert with climate change

Direct impacts risks of injury & death

heatwaves, extreme weather events

Displacement,Conflicts

shortages, prices: competition Relocation,

disruptionTrauma, deaths …..

Deaths Attributable to Climate Change in Year 2000

14 WHO statistical regions are, here, scaled by estimated annual mortality (in 2000) due to change in climate since ~1970. Selected causes of death.

(Patz, Gibbs et al, 2007: based on McMichael, Campbell-Lendrum, et al, 2004)

Estimated annual deaths due to climate change from: malnutrition (~80K), diarrhoea (~50K), malaria (~20K), flooding (~3K)

60 days:56,000 extra

deaths in Moscow and

Western Russia(Munich Re estimate)

Approx 8oC above normal

http://www.noaanews.noaa.gov/stories2011/20110309_russianheatwave.html

Temp oC

Extreme Heat (and Smoke) in Western Russia, Summer 2010: human (and crop) impacts

Baseline 2000 2025 2050

Ebi et al., 2005

Climate Change and Malaria Potential transmission in Zimbabwe

Bulawayo

Climate suitability:* red = high; blue/green = low

High probability

Medium probability

Low probability

Harare

Highlands

* Temperature + minimum seasonal rainfall

Ebi et al., 2005

Bulawayo

Harare

Baseline 2000 2025 2050

Climate Change and Malaria Potential transmission in Zimbabwe

Climate suitability: red = high; blue/green = low

Ebi et al., 2005

Bulawayo

Harare

Baseline 2000 2025 2050

Climate Change and Malaria Potential transmission in Zimbabwe

Climate suitability: red = high; blue/green = low

Schistosomiasis: Modelled future impact of warming on Schistosoma japonicum transmission in China

Source: Zhou et al., Am J Trop Med Hyg 2008

Potential transmission zone now

Zhou et al, 2008: “Recent data suggest that schistosomiasis is re-emerging in some settings [where previously good control]. ….

“Along with other reasons, climate change and ecologic transformations have been suggested as the underlying causes.”

2030: + 0.9oC

2050: + 1.6oC

Yang et al (2005):

Northwards drift, over past 4 decades, of winter ‘freezing zone’ that limits water-snail survival – associated with a 1.0-1.5oC temperature rise in SE China.

This has put an extra 21 million people at risk.

64

36

20

80

Percentage change in yields to 2050

-50 -20 0 +20 +50 +100

UN Devt Prog, 2009

Plus climate-related:• Flood/storm/fire damage• Droughts – range, severity• Pests (climate-sensitive)• Infectious diseases (ditto)

CLIMATE CHANGE: Poor Countries Projected to Fare Worst MODELLED CHANGES IN CEREAL GRAIN YIELDS, TO 2050

Modelled

and child nutrition/underweight

No. of additional deaths (1000s)

Sub-Saharan Africa

South Asia

Climate change: impact on crop yields and child under-nutrition (< 5 yrs) as cause of increased risk of infectious disease: Model-forecast

additional child deaths from infection to 2060 (excluding HIV/AIDS)

Year

Hughes et al., Bull WHO, 2011

1500 1550 1600 1650 1700 1750 1800

War Fatality Index,

Europe

Nth Hemi-sphere Temp

VariationoC

Rate of Migrations,

Europe

European Temp

Variationstandardised

units

Cold Period1570-1660

Zhang et al., PNAS, 2011

Coldest period, 1570-1660, in Europe during Little Ice Age: Relation to War and Displacement – as Food Yields Plummeted and Prices Rose

Photo-synthetic

activity

20o C 30o C 40o C

Food Yields: General Relationship of Temperature and Photosynthesis

0%

100%

∆ 2oC

∆ 2oC

Hsiang et al., Nature 2011

Affected(n= 93)

Weakly affected(n= 82) New civil conflicts

twice as likely to break out in El Niño years as in cooler La Niña years

Annual Conflict

Rate

(% of countries

with conflict)

El Niño Index (NINO3), oC (May-Dec average SST)

Civil Conflicts, 1950-2004, in Countries Affected and Little Affected by ENSO

And that’s

All

Summary Points• Climate change is a major part of today's 'planetary overload'

syndrome, due to escalating human pressures. It will progressively weaken Earth's life-support capacity.

• Beyond the evident health risks from increases in heatwaves,

weather disasters and some infectious diseases are potentially greater climate-related threats to food yields and nutrition, to freshwater supplies, and to community morale, mental health and stability.

• Climate-related food shortages, starvation, epidemic outbreaks and

associated social unrest endangers health, safety and survival – via conflict, warfare and displacement.