1. Climate Change and Health With special reference to risks facing small island- states Anthony J McMichael National Centre for Epidemiology & Population Health The Australian National University Canberra, ACT 0200

2. 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

3. Kilimanjaro 1970

4. Kilimanjaro 2000 Ice onKilimanjaro 0 5 10 15 1900192019401960198020002020 Year Area (km 2 )

5. 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.

6. 1960s1970s1980s1990s 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 One Earth is available (The planet’s total bio- capacity = 1.0) Number of Earths used by humanity Based on Wackernagel et al, 2002 Number of Earths

7. From: Steffen et al. In press 2004 Atmos CO 2 conc Domesticated land Loss of trop forest, woodland Coastal shrimp farmsFully exploited fisheries Climate disastersAv surface temp (NH) Atmos ozone loss Atmos CH 4 concAtmos N 2 O conc Coastal N 2 flux Global biodiversity Changes in environmental indicators, 1750 - 2000

8. Band of historical climatic variability 20 15 190021002000 14 16 17 18 13 19 Average Global Temperature ( O C) Year 205019501860 IPCC (2001) estimates a 1.4-5.8 o C increase Low High Central estimate = 2.5 o C (plus increased variability) This presents a rate-of-change problem for many natural systems/processes

9. Sea-level rise over coming centuries following 70 years of excess greenhouse gas emissions 200400600800 Time from start (years) 0.0 0.5 1.0 1.5 Sea-level rise (m) Total sea level rise Ocean Expansion Ice-melt Greenhouse gas emissions (“super-Kyoto” action) IPCC 2001 IPCC, 2001 Sea-Level Rise, over the coming millennium Peaking in 2050

10. 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)

11. Health effects Temperature-related illness and death Extreme weather- related health effects Air pollution-related health effects Water and food-borne diseases Vectorborne and rodentborne diseases Health Effects Temperature-related illness and death Extreme weather- related (floods, storms, etc.) health effects Air pollution-related health effects Human exposures Regional weather changes Heat waves Extreme weather Temperature Precipitation Regional weather changes Heat waves Extreme weather Temperature Sea-level rise Contamination pathways Transmission dynamics - - - -rodent Microbial changes: Contamination paths Transmission dynamics Water and food-borne diseases Vectorborne and borne diseases Climate Change Climate Change Changes in agro- ecosystems, hydrology Socioeconomic and demographic disruption Effects of food and water shortages Mental, nutritional, infectious-disease and other effects Modulating influences

12. 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].

13. VECTOR-BORNE DISEASE

14. 1990 2085 Estimated population at risk of dengue fever under “standard” climate change scenario: 1990, 2085 Source. Hales S et al. Lancet (online) 6 August 2002. http://image.thelancet.com/extras/01art11175web.pdfhttp://image.thelancet.com/extras/01art11175web.pdf.

15. Baseline 2000 Courtesy: Kris Ebi Modelling Malaria Transmissibility in Zimbabwe. I

16. Baseline 2000 2025 Courtesy: Kris Ebi Modelling Malaria Transmissibility in Zimbabwe. II

17. Baseline 2000 2025 2050 Courtesy: Kris Ebi Modelling Malaria Transmissibility in Zimbabwe. III

18. 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

19. That’ s All

20. Global average temperature ( o C) over the past millennium

21. 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 one- eighth of those in the United States. GHG: Coming Decades

22. From: Steffen et al. 2003 PopulationTotal real GDP Foreign direct investment Damming of riversFertiliser consumption Motor vehicles Water use MacDonalds Restaurants Urban population International tourism

23. Climate change impacts on rain-fed cereal production, 2080 (IIASA: Fischer et al, 2001) Need to convert estimates of regional food yields into estimates of changes in numbers of malnourished people

24. Scenario: A1F1 (high) CSIROMK2 Darwin Katherine Cairns Mackay Rockhampton Townsville Port Headland Broome........ Carnarvon. Darwin Katherine Cairns Mackay Rockhampton Townsville Port Headland Broome........ Brisbane. Model Estimate: Current Dengue Risk Region NCEPH/CSIRO/BoM, 2003 Dengue Fever: Estimated geographic region suitable for maintenance of Ae. aegypti, alternative climate scenarios for 2050

25. Categories of climate extremes Simple extremes based directly on climate statistics –Hot day = day with temperature > 95 th centile Complex, event-driven extremes –Droughts –Floods –Hurricanes/typhoons/tropical cyclones

26. Changes in climatic phenomenon Confidence in observed changes (latter half of 1900s) Probability of projected changes to 2100 Higher maximum temperatures - more hot days LikelyVery likely Higher minimum temperatures, - fewer cold days and frost days Very likely Increase of heat index over land areasLikelyVery likely More intense precipitation eventsLikely, (N mid to high latitudes) Very likely Increased summer continental drying and associated risk of drought Likely, in a few areasLikely, over most mid- latitude 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 dataLikely, over some areas IPCC WORKING GROUP I, Third Assessment Report, 2001