1. Health Impacts of Climate Change and Health Conference: Public health benefits of strategies to reduce greenhouse gas emissions London School of Hygiene and Tropical Medicine 25 Nov 2009 A.J. McMichael National Centre for Epidemiology and Population Health The Australian National University Canberra, Australia

2. Outline 1.Political context 2.Climate change: summary of recent science 3.Health Risks and Impacts 1.Research tasks; impact pathways 2.Examples: infectious disease, food yields/under-nutrition 4.Adaptation, Mitigation – and ‘Co-Benefits’ 5.Conclusion

3. Climate and Health Council Letter to Yvo de Boer, Exec Sec, UN Framework Convention on Climate Change, Nov 10, 2009 “Whilst human-induced climate change looms as the greatest threat to public health this century, the hopeful health message is: “What is good for the climate is good for health. “There is ample evidence to support this.”

4. The Cassandra Effect One who foresees, on available evidence, a likely disaster; yet judges that this can’t be prevented – and, that anyway, others won’t believe the forecast. CC is counter-intuitive: How could humans do that? ‘Climate’ vs. ‘weather’ confusion Cover-up of ignorance Influence of hired pens/lobbyists Resistance (esp. from ideological Right) to calls for collective action and government intervention. Spectre of “world government”.

5. LSHTM as ‘epicentre’: Potted History  1993-95: Health chapter, IPCC Second Assessment Report (1996)*: McMichael (co-chair), Haines, Kovats, et al  1996: WHO/UNEP book Climate Change and Human Health (eds: McMichael, Haines, Slooff, Kovats)  1999: McMichael AJ, Haines A (eds) Climate Change and Impacts on Human Health. London: Royal Society  1995-2000: LSHTM as international leader in CC/Hlth research; MRC (first) Program Grant awarded, 2000 (LSHTM, Univ East Anglia)  1998-2000: Health chapter, IPCC Third Assessment Report (2001) 2003-06: Health chapter, IPCC Fourth Assessment Report (2007)  2001-2004: WHO contract: estimation of burden of disease attributable to CC  2000s: Special reports with/for WHO – Vulnerability, Adaptation, etc.  2008: UK Dept Health: Health Effects of Climate Change in UK: ed. Kovats * no health chapter in IPCC First Assessment Report

6. CO 2 ppm Temp o C 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 390 370 350 330 310 290 270 250 14.5 14.3 14.1 13.9 13.7 13.5 Correlation between atmospheric carbon dioxide concentration and Earth’s average surface temperature Year CO 2 concentration Earth’s Temperature (background wobble due to natural influences) Graph from: Hanno, 2009

7. Greenhouse Gas Concentrations and Temperature Rise: Recent Science Global av temperature: clearcut (albeit naturally wobbly) uptrend Geophysical ‘fingerprints’ implicate increased GHG concentration as main cause of 0.7 o C rise since 1950 Global climate models, now highly-coupled, perform well on record of past ‘forcings’/temperature relationship – globally and regionally Six internationally-agreed plausible ‘human futures’ scenarios (i.e. story-lines yielding GHG emissions at high, medium, low levels) Repeated runs with many models yield a range of best central estimates for the 6 scenarios of 1.8-4.0 o C, by 2100 [IPCC 2007] Range in projected temperature rise to 2030-40 mostly due to residual uncertainties about climate system response to existing or imminent atmospheric GHGs Uncertainties re warming in later decades mostly reflect unknowable ‘human futures’

8. West Antarctic ice sheet Arctic ice sheets East Antarctic ice sheet 60myr 50myr 40myr 30myr 20myr 10myr Now Millions of Years Before Present 12 8 4 0 Temp o C * (vs 1961-90 av temp) +3 o C +5 o C Earth’s Temperature Chart, since Dinosaur Extinction 65m yrs ago ? Sea level 25-40 metres higher than today Tripati et al Science 2009 Paleocene * Temp measured at deep ocean +1.5 o C last 2m yr = ice-age

9. Climate Change occurring faster than expected IPCC’s Fourth Assessment Report (2007) now looks conservative [in addition to cautious review process] Subsequent research shows increasing rates of:  Global Greenhouse Gas emissions  Ice melting (Arctic sea ice, Greenland/Antarctic ice-sheets, alpine glaciers)  Sea level rise Also:  Increasing saturation of carbon ‘sinks’ (land and oceans)  Estimated amount of carbon stored in permafrost = twice the atmospheric carbon 1m: half of Bangladesh rice fields 2m: most of Mekong Delta

10. Cyclone Ketsana, Sept 2009 Approaching Vietnam Rainfall estimates, NOAA(USA), Sept 29 Northern Cambodia Hoi An, Central Vietnam

11. Climate Change and Health Research Tasks and Policy Foci Human society: Population size Economic activity Culture, governance Human pressure on environment Based on: McMichael et al., Brit med J, 2008 Adaptation: Reduce health impacts/risks Human impacts: Livelihoods Social stability Health Health Co- benefits? Unintended health effects Mitigation of Climate Change: Reduce GHG emissions Climate - environmental changes, affecting: Meteorological conditions Water flows Food yields Physical (protective) buffers Microbial activity Extreme weather events 4 Risks to humans better understood 2 3 Natural environmental processes 1 a-c Need for local prevention

12. Climate Change: Health Impact Pathways Physical systems (river flows, soil moisture, ocean temp) Biological cycles, in nature … & Ecological links/function Economic/social impacts: infrastructure, farm/factory production, GDP growth, jobs, displacement Human Health: Injuries/deaths Thermal stress Indirect health impacts – ecologically mediated Indirect health impacts – socially mediated Direct impacts (extreme weather events, heatwaves, air pollutants, etc.) Infectious diseases Under-nutrition Mental stresses Other disorders Climate Change Impacts

13. Regions afflicted by problems due to environmental stresses: population pressure water shortage climate change affecting crops sea level rise pre-existing hunger armed conflict, current/recent From UK Ministry of Defence [May RM, 2007 Lowy Institute Lecture. Sydney] Climate Change: Multiplier of Conflicts and Regional Tensions

14. Deaths (thousands)DALYs (millions) 20002030 Deaths and DALYs attributable to Climate Change, 2000 & 2030 Selected conditions in developing countries WHO/McMichael,Campbell-Lendrum, Kovats et al, 2004 Now (2000) Future (2030) DeathsTotal Burden

15. Climate and Infectious Disease Climatic conditions set geographic and seasonal limits of potential transmission. Other environmental, social and behavioural factors – and public health strategies – determine where/when actual transmission occurs.

16. Model-fitted relationship of monthly Salmonellosis case counts in relation to monthly av. temperature in five Australian cities, 1991-2001 0 10 20 30 40 50 60 70 80 90 100 910111213141516171819202122232425262728 Average MonthlyTemperature o C Salmonella count Perth Brisbane Adelaide Melbourne Sydney D’Souza et al., 2003

17. Daily temperature 19971993 Overall estimate from regression analysis: 7% increase in daily cases per 1 o C rise Daily hospitalizations for diarrhoea, by daily temperature: Lima, Peru. (Shaded region is 1997-98 El Niño event) Checkley et al, Lancet 2000 Daily Hospitalisations

18. Estimated Mortality Impacts of Climate Change: Year 2000 14 WHO regions scaled according to estimated annual death rates due to the change in climate since c.1970. (Patz, Gibbs et al, 2007: based on McMichael, Campbell-Lendrum, Kovats, et al, 2004) Estimated annual deaths due to climate change: malnutrition (~80K), diarrhoea (~50K), malaria (~20K), flooding (~3K)

19. Bluetongue virus: Has climate change caused a northwards extension, in Europe, of Culicoides midge vectors? 1998: Northern limit C. imicola midge 2004: Northern limit C. imicola midge 1998: Northern range of virus (in sheep) 2004: Northern range* of virus (in sheep) Source: Purse et al, 2005 Nature Reviews Microbiology C. pulcarisC. obselitus C. imicola Current northern limit Northern limit < 1998 Northern limit Southern limit * Suggests additional midge species are also now contributing Midge species: potential vectors of BT Virus [“European” Midge species]

20. Schistosomiasis: Modelled Future Impact of Climate Change on Schistosoma japonicum Transmission in China Source: Zhou et al., Potential Impact of Climate Change on Schistosomiasis Transmission in China Am J Trop Med Hyg 2008;78:188–194. 2030: + 0.9 o CNow 2050: + 1.6 o C “Recent data suggest that schistosomiasis is re-emerging in some settings [with previous successful disease control]. …. “Along with other reasons, climate change and ecologic transformations have been suggested as the underlying causes.” Northwards drift, over past 4 decades, of the winter ‘freezing zone’ that limits water-snail survival – associated with 1-1.5 o C temperature rise in SE China

21. NCEPH/CSIRO/BoM/UnivOtago, 2003 DENGUE FEVER: Estimated geographic region suitable for A. aegypti vector, and hence transmission: Climate conditions now and in alternative scenarios for 2050 2050 risk region: Medium GHG emissions scenario Darwin Katherine Cairns Mackay Rockhampton Townsville Port Hedland Broome........ Carnarvon. Darwin Katherine Cairns Mackay Rockhampton Townsville Port Hedland Broome.. Brisbane....... Current risk region, for dengue transmission Darwin Katherine Cairns Mackay Rockhampton Townsville Port Hedland Broome........ Carnarvon. 2050 risk region: High GHG emissions scenario Brisbane Global statistical model (Hales), applied to Australia: mosquito survival in relation to water vapour pressure (rainfall, humidity).

22. TRANSMISSION POTENTIAL 0 0.2 0.4 0.6 0.8 1 14172023262932353841 Temperature (°C) Plasmodium Incubation time 0 10 20 30 40 50 152025303540 (days) Biting frequency 0 0.1 0.2 0.3 10152025303540 Temp (°C) (per day) Survival probability 0 0.2 0.4 0.6 0.8 1 10152025303540 (per day) Temp (°C) Malaria Transmissibility: Temperature and Biology P.vivax P.falciparum Based on Martens WJM, 1998 ---------------- Mosquito ------------------

23. 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

24. 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

25. 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

26. Photo- synthetic activity 20 o C30 o C40 o C Food Yields: General Relationship of Temperature and Photosynthesis 0% 100% Example: Field & Lobell. Environmental Research Letters, 2007: Globally averaged: +0.5 o C reduces crop yields by 3-5%. So: +2 o C would mean 12-20% fall in global grain production. +2 o C Plus: Floods, storms, fires Droughts – range, severity Pests Diseases

27. World -0.6 to-0.9 Developed countries +2.7 to+9.0 Developing countries -3.3 to-7.2 Southeast Asia -2.5 to-7.8 South Asia -18.2 to -22.1 Sub-Saharan Africa -3.9 to -7.5 Latin America +5.2 to +12.5 From: Tubiello & Fischer, 2007 % Change (range) Modelled impact of climate change on global cereal grain production: Percent change, 1990-to-2080

28. Are the zones being pushed south, by warming? … and here? Health Consequences? Marked wet summer and dry winter Wet summer and low winter rainfall Uniform rainfall Marked wet winter and dry summer Low rainfall Wet winter and low summer rainfall Arid Winter dominant Winter Summer dominantSummerUniform Crucial for wheat-belt Australia: Climate change, seasonal rainfall zones, farm yields, health impacts

29. Mitigation and Adaptation Avoiding the Unmanageable Managing the Unavoidable

30. ‘Vulnerability’ and ‘Adaptation’ D Schroter et al, 2004

31. External exposure: climatic and environmental conditions Sensitivity of exposed population: immune status, nutritional status, housing conditions, etc. Adaptive Capacity: Local governance Community cohesion Funds available Public health capacity Potential health impact - risk of occurrence of malaria Actual adaptive actions e.g. Regional government Meteorological forecasts Community Surface-water control Mosquito spraying Rapid case treatment Household/personal House repairs Bed-nets Net Vulnerability to risk of malaria Population Health Impact: actual outcome Vulnerability, Adaptation and Malaria Risk

32. Reducing Health Impacts of Climate Change … Health Co- Benefits as ‘bonus’ Disease burden Mitigation begins emissions reduction (etc.) Potential health impact of climate change now 2050 2100 Health Co-Benefits (local/regional) Baseline burden Health impact averted by mitigation Impact avoidance via adaptation

33. Urgent Policy Tasks – to reduce: Atmospheric GHG concentrations Vulnerability of populations Pre-existing (amplifiable) disease rates

34. Watch out on Starboard !! WAIT: We are in the middle of a conference on iceberg avoidance TITANIC