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Health Impacts of Climate Change and Health Conference: Public health benefits of strategies to reduce greenhouse gas e

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

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Health Impacts of Climate Change and Health Conference: Public health benefits of strategies to reduce greenhouse gas e

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  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 • Political context • Climate change:summary of recent science • Health Risks and Impacts • Research tasks; impact pathways • Examples: infectious disease, food yields/under-nutrition • Adaptation, Mitigation – and ‘Co-Benefits’ • 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. Correlation between atmospheric carbon dioxide concentration and Earth’s average surface temperature 14.5 14.3 14.1 13.9 13.7 13.5 390 370 350 330 310 290 270 250 Earth’s Temperature (background wobble due to natural influences) Temp oC CO2 concentration CO2 ppm 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 Year 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 0.7oC 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 1.8-4.0oC, 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. +5oC +3oC Earth’s Temperature Chart, since Dinosaur Extinction 65m yrs ago Arctic ice sheets East Antarctic ice sheet West Antarctic ice sheet Paleocene 12 8 4 0 ? +1.5oC Temp oC* (vs 1961-90 av temp) last 2m yr = ice-age 60myr 50myr 40myr 30myr 20myr 10myr Now Millions of Years Before Present Sea level 25-40 metres higher than today Tripati et al Science 2009 * Temp measured at deep ocean

  9. Climate Change occurringfaster 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 Hoi An, Central Vietnam Northern Cambodia Rainfall estimates, NOAA(USA), Sept 29

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

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

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

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

  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. Perth Brisbane Adelaide Melbourne Sydney Model-fitted relationship of monthly Salmonellosis casecounts in relation to monthly av. temperature in five Australian cities, 1991-2001 100 90 80 70 60 Salmonella count 50 40 30 20 10 0 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 D’Souza et al., 2003 Average MonthlyTemperature oC

  17. Daily hospitalizations for diarrhoea, by daily temperature: Lima, Peru. (Shaded region is 1997-98 El Niño event) Checkley et al, Lancet 2000 Daily Hospitalisations Overall estimate from regression analysis: 7% increase in daily cases per 1o C rise Daily temperature 1993 1997

  18. Estimated Mortality Impacts of Climate Change: Year 2000 Estimated annual deaths due to climate change: malnutrition (~80K), diarrhoea (~50K), malaria (~20K), flooding (~3K) 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)

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

  20. Schistosomiasis: Modelled Future Impact of Climate Change on Schistosoma japonicum Transmission in China Now 2030: + 0.9oC Northwards drift, over past 4 decades, of the winter ‘freezing zone’ that limits water-snail survival – associated with 1-1.5oC temperature rise in SE China 2050: + 1.6oC “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.” Source: Zhou et al., Potential Impact of Climate Change on Schistosomiasis Transmission in China Am J Trop Med Hyg 2008;78:188–194.

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

  22. Malaria Transmissibility: Temperature and Biology P.vivax P.falciparum Plasmodium Incubation time ---------------- Mosquito ------------------ Survival probability Biting frequency 1 50 0.3 0.8 40 0.6 (per day) 30 0.2 (days) (per day) 0.4 20 0.1 0.2 10 0 0 0 15 20 25 30 35 40 10 15 20 25 30 35 40 10 15 20 25 30 35 40 Temp (°C) Temp (°C) Temp (°C) TRANSMISSION POTENTIAL 1 0.8 0.6 0.4 0.2 Based on Martens WJM, 1998 0 14 17 20 23 26 29 32 35 38 41 Temperature (°C)

  23. Climate Change and Malaria Potential transmission in Zimbabwe Baseline 20002025 2050 Harare Climate suitability: red = high; blue/green = low Low probability Highlands Medium probability High probability Bulawayo Ebi et al., 2005

  24. Harare Bulawayo Climate Change and Malaria Potential transmission in Zimbabwe Baseline 20002025 2050 Climate suitability: red = high; blue/green = low Ebi et al., 2005

  25. Harare Bulawayo Climate Change and Malaria Potential transmission in Zimbabwe Baseline 20002025 2050 Climate suitability: red = high; blue/green = low Ebi et al., 2005

  26. Food Yields: General Relationship of Temperature and Photosynthesis 100% Photo-synthetic activity +2oC • Plus: • Floods, storms, fires • Droughts – range, severity • Pests • Diseases +2oC 0% 20o C 30o C 40o C Example: Field & Lobell. Environmental Research Letters, 2007: Globally averaged: +0.5oC reduces crop yields by 3-5%. So: +2oC would mean 12-20% fall in global grain production.

  27. Modelled impact of climate change on global cereal grain production: Percent change, 1990-to-2080 % Change (range) 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 -18.2to -22.1 Sub-Saharan Africa -3.9 to -7.5 Latin America +5.2 to +12.5 From: Tubiello & Fischer, 2007

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

  29. Mitigation and Adaptation Avoiding the Unmanageable Managing the Unavoidable

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

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

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

  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

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