Climate change and its impact on health in the Pacific Basin

1. Climate change and its impact on health in the Pacific Basin Alistair Woodward School of Population Health University of Auckland

2. Main points • Climate change represents a new category of environmental problem • Increased frequency of extreme weather will have most dramatic consequences for human health • Changes in surface temperature, water availability and sea level will also affect the Pacific Basin • In response, mitigation and adaptation are both required

3. Climate change “change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods” UN Convention on Climate Change

4. Classic environmental health

5. New category of problem - global overload

6. PREDICTED CLIMATE CHANGE UNDER THREE SCENARIOS (UKMO) 4 Business as Usual S 750 S 550 Temp increase (o C) 3 2 1 1900 2000 2100 2200 Time

8. Changes in river runoff from the present day to the 2080s Unmitigated emissions University of Southampton

9. In the 2050s, the Pacific will be • warmer • drier • subject to more intense rainfall • experiencing more intense storms • facing sea level rise of about 20 cm

10. Direct Thermal extremes Floods and storms Indirect Vector-borne disease Other infections Food shortages Worsening pollution Social disruption How climate change can cause disease and injury

11. HEAT WAVE - EUROPE An Estimated 14,800 Deaths occurred in France Heat Index, Summer 2003

12. Causes of European heatwave? “well outside the range of expected variability” “human-induced component of climate change has more than doubled the risk of heatwaves as extreme as the 2003 event” Stott et al, Nature 2004;432:610-4

13. Small island regions and coastal flooding, HadCM2: thousands of people flooded per year from Nicholls et al, 1999

14. Increased sea surface temperatures associated with coral bleaching and increased rates of ciguatera (fish poisoning) in SW Pacific

15. Dengue • Dengue fever is the world’s most important viral vector-borne disease. • Affects hundreds of millions of people each year • Transmitted predominantly by a single species of mosquito, Aedes aegypti. • This species is adapted to living near to human habitation, feeds during the day and prefers humans to other species.

16. Model of baseline transmission (1961-1990 climate)

17. Model of future transmission (2080s climate)

18. Climate change - what to do about it? • Mitigation • Reduce the use of oil and coal • Increase uptake of CO2 by carbon sinks • Capture, store and re-use emissions • Adaptation • Manage ecosystems to reduce impact of climate change (eg forests, marine reserves) • Design built environment for an altered climate • Health system change to reduce vulnerability (eg early warning systems for heatwaves) • Social and economic policy (eg development assistance, trade, migration)

19. Main points • Climate change represents a new category of environmental problem • Increased frequency of extreme weather will have most dramatic consequences for human health • Changes in surface temperature, water availability and sea level will also affect the Pacific Basin • In response, mitigation and adaptation are both required