Climate Change: the “debate” <ul><li>Skepticism is now receding. We know that: </li></ul><ul><li>Greenhouse gas (GHG) concentrations are increasing </li></ul><ul><li>GHGs affect the climate system (thankfully!) </li></ul><ul><li>World average temperature has risen relatively fast over the past 30 years </li></ul><ul><li>Sea-level rise is gradually accelerating </li></ul><ul><li>Many temperature-sensitive systems/processes have changed over the past two decades </li></ul>
Kilimanjaro 2000 Ice on Kilimanjaro 0 5 10 15 1900 1920 1940 1960 1980 2000 2020 Year Area (km 2 )
Climate Change: Basic Issues <ul><li>Earth’s climate varies naturally – because of a variety of cosmological and geological processes. </li></ul><ul><li>“ Climate change” refers to an additional , and relatively rapid, change induced by human actions. </li></ul><ul><li>The additional change – several degrees C within a century – will disrupt the foundations of life on Earth. </li></ul><ul><li>Ecosystems and life in general have evolved within a narrow band of climatic-environmental conditions. </li></ul>
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 1960s 1970s 1980s 1990s
From: Steffen et al. In press 2004 Atmos CO 2 conc Domesticated land Loss of trop forest, woodland Coastal shrimp farms Fully exploited fisheries Climate disasters Av surface temp (NH) Atmos ozone loss Atmos CH 4 conc Atmos N 2 O conc Coastal N 2 flux Global biodiversity Changes in environmental indicators, 1750 - 2000
Sea-level rise over coming centuries following 70 years of excess greenhouse gas emissions 200 400 600 800 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 Sea-Level Rise, over the coming millennium Peaking in 2050
SLR Risks to Small Island-States <ul><li>Coastal flooding </li></ul><ul><li>Amplified storm surges </li></ul><ul><li>Damaged coastal infrastructure (roads, etc.) </li></ul><ul><li>Salination of island fresh-water (esp. subterranean cells) </li></ul><ul><li>Impaired crop production </li></ul><ul><li>Population displacement: diverse health risks (nutrition, infection, mental health) </li></ul>
Health effects Temperature - related illness and death Extreme weather - related health effects Air pollution - related health effects Water and food - borne diseases Vector borne and rodent borne diseases Health Effects Temperature-related illness and death Air pollution-related health effects Human exposures Regional weather changes • Heat waves • Extreme weather • Temperature • Precipitation Regional weather changes • Heat waves • Extreme weather • Temperature • <ul><li>Sea-level rise </li></ul>Extreme weather- related (floods, storms, etc.) health effects Contamination pathways Transmission dynamics - - - - rodent Microbial changes: Contamination paths Transmission dynamics Water and food-borne diseases Vector borne 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
ENSO and climate change <ul><li>The effect of global climate change on the future frequency and/or amplitude of El Niño is uncertain . </li></ul><ul><li>Events may become more frequent or more intense. </li></ul><ul><li>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 </li></ul>
1990 2085 Estimated population at risk of dengue fever under “standard” climate change scenario: 1990, 2085 .
Baseline 2000 Courtesy: Kris Ebi Modelling Malaria Transmissibility in Zimbabwe. I
Baseline 2000 2025 Courtesy: Kris Ebi Modelling Malaria Transmissibility in Zimbabwe. II
Courtesy: Kris Ebi Modelling Malaria Transmissibility in Zimbabwe. III
What Should Health Ministries Do? <ul><li>Commission/conduct national assessments of risks to health from CC (and SLR) </li></ul><ul><li>Participate in emergency management preparedness (communications, facilities, skills) </li></ul><ul><li>Argue the centrality of population health as the real “bottom line” in the sustainability debate </li></ul><ul><li>Make links with other ministries – education, primary industry (agriculture), fisheries, development planning, etc. </li></ul><ul><li>Highlight the sense and cost-savings of adaptation strategies, to lessen adverse impacts </li></ul>
Global average temperature ( o C) over the past millennium
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
Need to convert estimates of regional food yields into estimates of changes in numbers of malnourished people
Categories of climate extremes <ul><li>Simple extremes based directly on climate statistics </li></ul><ul><ul><li>Hot day = day with temperature > 95 th centile </li></ul></ul><ul><li>Complex, event-driven extremes </li></ul><ul><ul><li>Droughts </li></ul></ul><ul><ul><li>Floods </li></ul></ul><ul><ul><li>Hurricanes/typhoons/tropical cyclones </li></ul></ul>
Changes in climatic phenomenon Confidence in observed changes (latter half of 1900s) Probability of projected changes to 2100 Higher maximum temperatures - more hot days Likely Very likely Higher minimum temperatures, - fewer cold days and frost days Very likely Very likely Increase of heat index over land areas Likely Very likely More intense precipitation events Likely, (N mid to high latitudes) Very likely Increased summer continental drying and associated risk of drought Likely, in a few areas Likely, 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 data Likely, over some areas
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