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

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

“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 Climate change

Classic environmental health

New category of problem - global overload

Time Business as Usual S 750 S 550 PREDICTED CLIMATE CHANGE UNDER THREE SCENARIOS (UKMO) Temp increase ( o C)

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

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

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

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

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

Small island regions and coastal flooding, HadCM2: thousands of people flooded per year region business as usual adaptation Caribbean Indian Ocean Pacific Ocean from Nicholls et al, 1999

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

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.

Model of baseline transmission ( climate)

Model of future transmission (2080s climate)

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)

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