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Climatic change and its impacts on human societies

Climatic change and its impacts on human societies. Martin Beniston Director, Institute for Environmental Studies The University of Geneva Martin.Beniston@unige.ch. Geneva, October 8, 2009. Summary. Introduction Past climates and societal change Climatic change by 2100

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Climatic change and its impacts on human societies

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  1. Climatic change and its impacts on human societies Martin BenistonDirector, Institute for Environmental StudiesThe University of GenevaMartin.Beniston@unige.ch Geneva, October 8, 2009

  2. Summary • Introduction • Past climates and societal change • Climatic change by 2100 • Climate impacts, loss of resources, potential for conflict • Conclusions

  3. 1 • Introduction • Past climates and societal change • Climatic change by 2100 • Climate impacts, loss of resources, potential for conflict • Conclusions

  4. Climate and determinants for human survival Shelter Climate Water Food Health

  5. Revenue < $1/day No access to clean water Illiteracy No access to health care Mortality below age of 40 Under- nourished children *: Climate driven Socio-economic problems:some already driven by climate * * * * 0 200 400 600 800 1000 1200 1400 World Resources Institute, 2005 Millions

  6. 2 • Introduction • Past climates and societal change • Climatic change by 2100 • Climate impacts, loss of resources, potential for conflict • Conclusions

  7. Climate constraints and societal consequences Droughts Cold and heat waves Direct climate pressures Sea-level rise Propagation of diseases Indirect climate effects Persistence Low Amplification of a pre-existing crisis High Collapse of the conditions for human survival

  8. The « year without summer » as painted by Turner…

  9. The climate event around 540 AD and huge change in the Orient • Around 535-540 AD, a huge cold wave probably associated with a volcanic eruption affected much of Europe and the Near East. The Greek philosopher Procopius writes: • « …the sun was without strength, like the moon, during this entire year [536] ; it was as if the sun was in a permanent eclipse, for its rays were not very bright… »

  10. The climate event around 540 AD and huge change in the Orient • This was the coldest period probably within the preceding 4000 years, leading to: • failing crops, year after year, with repeated famines • the first major pandemic in Europe (the Justinian Plague, in 541-542) that killed an estimated 10000 people a day in Constantinople

  11. The climate event around 540 AD and huge change in the Orient • Certain historians consider that this climate event was a major driver of events in the Orient: • the final blow to the Roman Empire, whose capital was in Constantinope • the Empire, weakened on all fronts by wars (Ostrogoths in Italy, Vandals in Carthage) was unable to withstand the assaults of the Justinian plague • the losses in tax revenue, as a result of sick or dying populations, meant that the economic and military might of the Empire could no longer be sustained… • changes in the balance of power occur in the region, with the surge of Arabic culture

  12. The collapse of the Anasazi

  13. Culture and climate in the American South-West Maya rebirth (Chichen Itza) Barbarian invasions Destruction of Teotihuacan Surge of classical civilizations (Teotihuacan,Oaxaca, etc.) First records of the Anasazi Pueblo phase of the Anasazi End of the Maya civilizations The Aztecs found Tenochitlan (Mexico) Cortez and the Conquistadores Destroy the Aztecs M. Hughes et al., University of Arizona Disappearance of the Anasazi

  14. Regions typically affected by long droughts

  15. 3 • Introduction • Past climates and societal change • Climatic change by 2100 • Climate impacts, loss of resources, potential for conflict • Conclusions

  16. Climate futures 6.0 Strong emissions 5.0 4.0 3.0 DT with respect to the 20th Century [°C] Moderate emissions 2.0 1.0 0.8 0.6 0.4 0.2 IPCC 2007 0 -0.2 -0.4 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2050 2100

  17. Global temperature change by 2100(IPCC, 2007)

  18. Global precipitation change(IPCC AR4, 2007)

  19. 4 • Introduction • Past climates and societal change • Climatic change by 2100 • Climate impacts, loss of resources, potential for conflict • Conclusions

  20. Climate Multiple stresses leading to socio-economic hardships Water availability Less water Smaller access to technology Access to technology Poverty Food shortages Food security Demography Smaller access to education Risks of epidemics Access to health care Education/ Awareness

  21. DT compated to 1980-1999 Climate impacts(IPCC, 2007) 0 1 2 3 4 5 Water More water in the Tropics and the high latitudes Less water in the mid latitudes and in the arid zones Millions of persons affected by water stress 30% Species extinctions Large-scale extinctions Eco- systems Coral bleaching Widespread coral mortality Ecosystems become carbon sources 15% 40% New geographical distribution of species Elevated fire risks Negative impacts on small farms Agri- culture Reduction of all cereal productivity in low latitudes Reduction of some cereal productivity in low latitudes Increase in the productivity of some cereals in high latitudes Reduction of the productivity of some cereals in high latitudes Oceans Increased damage by storms and coastal flooding Loss of 30% of coastal ecosystems 100-150 million persons affected by sea-level rise and permanent flooding Health Increases in malnutrition, cardio-vascular and infectious diseases Morbidity and mortality linked to extrême events (heatwaves, droughts, floods New areas open to the propagation of vector-borne diseases Health systems under considerable stress

  22. Coastal-zone vulnerability by 2100 IPCC, 2007

  23. Changes in hurricane frequency and intensity 160 Cat 3 Cat 4 Cat 5 Cat 3 Cat 4 Cat 5 1961-1990 120 K. Emmanuel, Science, 2006 1961-1990 80 2071-2100 2071-2100 Number of events 40 0 880 100 150 200 960 940 920 900 Central pressure [hPa] Total precipitation [mm/6 h]

  24. Water availability and standards of living • 1,000 m3 of water per inhabitant and per year is generally considered by the UN to be a threshold indicative of a « comfortable » standard of living • 50% of the world’s population does not attain this threshold… • … and close to 1 billion do not have regular access to potable water • Source: UN International Conference on Water Resources, Paris, 1998

  25. Water availability 2000 4500 2050, without climatic change 4000 2050, with climatic change 3500 3000 2500 m3/person/year 2000 1500 1000 500 IPCC, 2001 0 Japan Spain India Haiti

  26. Water quality and infant mortality 2 5 0 Ethiopia Europe N. America Australia/NZ Japan Nigeria 2 0 0 Ex-Zaire Cambodia Sudan 1 5 0 Child mortality (< 5 years) per 1000 population Pakistan 1 0 0 Peru Egypt Indonesia Honduras Syria 5 0 Iran Mexico China 0 0 2 0 4 0 6 0 8 0 1 0 0 % of population with access to potable water • Source: UN International Conference on Water Resources, Paris, 1998

  27. In the future, climatic change will exacerbate already-critical situations • Water resources in many regions will be a function of demographic trends • 1990: 550 million persons in 20 countries were confronted with permanent problems of access to clean water (according to UN statistics) • 2025: 1’500 million persons in 35 countries • Climatic change will add an extra burden • Arid and semi-arid regions • Overcrowded megacities…

  28. Sharing of water resources is already today a source of tension... • One cannot exclude the risk of regional conflicts for the appropriation of a resource that in many parts of the world will become rarer, either because of climatic change or demography (or both!) • Israel and its Arab neighbors (Jordan river; ground water) • The GAP program in Turkey, headwaters of the Tigris and Euphrates that feed into Irak and Syria • Egypt and its upstream neighbors along the Nile, particularly the Sudan • …

  29. Changes in cereal yields 2020 2050 2080 -40% -30% -20% -10% 0% +10% +20% +30% Changes compared to 1990

  30. Risk of desertification in Africa Deserts Real risks Major risks

  31. Natural AND human drivers of desertification (J. Charney model) Reduction of vegetation cover Reduction of vegetation cover Less precipitation More reflecting surfaces Less clouds Less energy to transfer moisture to the atmosphere

  32. Food security problems in arid zones of Africa 2500 60 Carbohydrates 2000 55 Protein 1500 Protein (grams/cap/yr) Carbohydrates (cal/cap/yr) Nitrogen fertilizers (1000t) 1000 50 Use of fertilizers 500 0 45 1960 1970 1980 1990 2000 Scholes, RJ and R Biggs (eds) 2004: Ecosystem Services in southern Africa; a regional assessment. CSIR, Pretoria

  33. Processes leading to desertification 3.0 Deforestation 2.5 Overgrazing Agriculture 2.0 106 km2 1.5 1.0 0.5 0.0 Africa Asia Australia Europe North America South America

  34. Vector-borne and water-borne diseases (WHO, 2005) Diseases Relation to Populations climate at risk (2050) Malaria Temp., humidity (moskitos) 2.2 billion Dengue Temp., humidity 2.5 billion Schistosomiasis Water for the snails 600 million Sleeping sickness Temp., humidity (flies) 55 million Chagas disease Temp., humidity (flies) 100 million Leishmaniasis Temp., humidity (flies) 350 million River blindess Water for the black flies 120 million

  35. 5 • Introduction • Past climates and societal change • Climatic change by 2100 • Climate impacts, loss of resources, potential for conflict • Conclusions

  36. Conclusions • In a world where the disparity of wealth, culture, or access to technology is very different from one region to another, environmental change will have different effects on different people • Outmigration, a strategy used throughout much of, will be a complex mix of economic, political and environmental driving forces – complicated by political borders and barriers to migration • In certain regions, environmental factors may be a dominant driver, in others they may just exacerbate a criticial pre-existing socio-economic situation

  37. Conclusions • In view of the long inertia of environmental and climatic change, it will not be possible to stop rapidly current trends • Adaptation to change thus seems to be the only viable strategy to avoid social hardship today and in the future • Health • Access to water and food • Shelter • This raises ethical questions of equal access to resources and a genuine move towards the eradication of poverty • Aspects of climate and global change urgently need to be integrated into future planning • Humanitarian aid • Development aid • One readily-applicable approach is to raise awareness of vulnerable populations to negative environmental impacts through education and outreach activities

  38. Luxembourg Denmark Netherlands Norway Ireland Japan Sweden Swizerland Finland Canada Spain Germany France Australia UK Italy USA Development aid as a fraction of GDP (2005) UNCED-92 objective 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 % OECD average

  39. Climatic change and its impacts on human societies Many thanks for your attention www.unige.ch/climateMartin.Beniston@unige.ch Geneva, October 8, 2009

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