Effects of climate change on infectious diseases

1. CIS oƒ HDGC Carnegie Mellon Effects of climate change on infectious diseases Funded BY: National Science Foundation, USDOE, ExxonMobil, EPRI, NOAA, USEPA, and API My Thanks to: Elizabeth Casman, Ilya Fischhoff, Baruch Fischhoff, Lester lave, Emilio Moran, Richard Tol, Duane Gubler & the organizers of the conference Hadi Dowlatabadi Center for Integrated Study of the Human Dimensions of Global Change, Carnegie Mellon University, & University Fellow, Resources for the Future

2. Outline of this talk Background on climate and disease Climate & politics of disease What is climate change? Projecting malaria & climate change Other determinants of disease Challenges ahead

3. Climate determines the conditions permissive of infectious diseases • For vector borne diseases this would be the conditions suitable for mutual development of the vector and pathogen. • Climate conditions can determine whether the pathogen and humans come into contact with one another by affecting human behaviour and pathogen ecology. • Extreme climate events can overwhelm waste water management infrastructures. • Adverse climate conditions can affect food production, lead to hunger and hence immune suppression. • …

4. How important is climate change? • Climate change can overwhelm the adaptive capacity of human-habitat interactions, especially where there is little access to resources and technology. • Climate change is important to health in affecting: • Ecology of managed and unmanaged systems. • Patterns of human activity and movement. • Frequency of extreme events. • Changes in atmospheric chemistry. • The key question is whether climate change is important vis-à-vis other global change processes.

5. Many fear climate change will spread tropical diseases like Malaria

6. Outline of this talk Background on climate and disease Climate & politics of disease What is climate change? Projecting malaria & climate change Other determinants of disease Challenges ahead

7. What is climate change? • The idea is that we have changed the surface of the earth, and its atmosphere to such an extent that: • Incoming solar radiation is bounced back into space differently, with more energy staying in the atmosphere. • This will affect the flow of energy & water between land, atmosphere and oceans. • Changing patterns of temperatures, clouds and precipitation. • We bring about climate change through: burning fossil fuels, agriculture, draining wetlands, building dams, cutting down trees and paving over paradise...

8. Monthly temperatures for Pittsburgh 1871-1993

9. Monthly precipitation for Pittsburgh 1871-1993

10. CAA/OPEC SO2 TSP & SO2 2.5°C Change in annual average temperature 1871-1993

11. Trends in mean monthly temperature

12. Change in total annual precipitation 1871-1993

13. Change in total annual precipitation 1871-1993

14. Outline of this talk Background on climate and disease Climate & politics of disease What is climate change? Projecting malaria & climate change Other determinants of disease Challenges ahead

15. Other global change phenomena which can impact prevalence of infectious diseases • Prosperity. • Demographics. • Movement of people and goods. • Immunity status. • Land use and cover. • Knowledge & technology. • Social norms. • Security.

16. Economic Prosperity • The US has seen sustained growth in the overall economic prosperity of its population over the past century averaging more than 2% p.a. • There has been miraculous growth in Far Eastern countries, at times 3 to 4 times faster than the US, but these miracles have recently floundered. • Meanwhile, there has not been any improvement in living conditions of a large fraction of the world’s population.

17. Population • Population growth rates are falling. • The earth’s population is not expected to exceed 12 billion by 2100. • Populations are expected to grow significantly older, from ~ 5% over 60 today to ~20% over 60 in 2100. • Urban and peri-urban populations are growing rapidly, especially in less prosperous and lower-middle income countries.

18. Comparing Under 5 mortality rates: Urban/Rural by income class

19. Forced migrations • Internally displaced populations and international refugees rarely have access to health services & can be potent vectors. • Their rate in (#/1000) has grown 50% over the past 30 years. Source: CIPEC

20. Immunity status • Over 500M are malnourished, but their rate and numbers have been falling. • Over 35M are HIV positive, but their rate and numbers have been rising Sources: FAO and WHO

21. Where & When? Indiana ~1820 cf. ~1990 Forest Wetland Prairie Water Row Crop Pasture/Grassland Urban Courtesy of the Center for the Study of Institutions, Population and Environmental Change, Indiana University, Bloomington

22. Deforestation along the TransAmazon Highway: from before 1970 through 1991 Courtesy of the Anthropological Center for Training and Research on Global Environmental Change, Indiana University, Bloomington

23. Genetic engineering Designer pharmacology Remote sensing Diagnostics on a chip But few, if any, of these innovations are within reach of and address the needs of the poorest nations. Knowledge and technology Source: Nature 1997

24. Social norms • All syntheses on how to succeed in combating infectious disease draw attention to the importance of the following factors: • Equity. • Political resolve to provide public health. • Synergy of intervention with other social goals.

25. Security • Extreme natural events and absence of services can lead to: • Internal displacements, • International refugees, and • Hunger • More often though, these are caused by war and social discord.

26. Global change is about multiple interaction paths LocalEcology Famine Climate change War Infectiousdisease Population Immune status Prosperity Knowledge Mobility Social Norms

27. Climate change, extreme events and Cryptosporidiosis year 20 day 1 day 2 day 3 day 4 day 5 day 6 week 2 year 2 Climate change Detection in water Detection in water Boil water advisory Boil water advisory Torrential rain Detection in patients Overwhelms sewage system Indirect alert Crypto-in water supply Epidemic R&D for better detection Revise sewage handling Reconsider land use patterns Understand what happened

28. Outline of this talk Background on climate and disease Climate & politics of disease What is climate change? Projecting malaria & climate change Other determinants of disease Challenges ahead

29. Climate determines the potential range of vectors but public health determines disease outbreaks Source: WHO

30. Reported cases of Dengue 1980-96:Does climate change abruptly at the border? Source: US National Assessment

31. Life expectancy is a political mapnot a climatic one

32. Life expectancy & GDP

33. Disruption of health services can be disastrous, but easily recoverable Diphtheria Cases (x1000) in SU & FSU

34. 40,000 30,000 20,000 10,000 0 1990 1991 1992 1993 1994 1995 1996 1997 Disruption of health services can be disastrous, and evolve into a long-term nightmare Malaria Incidence in Newly Independent States Source: WHO

35. Outline of this talk Background on climate and disease Climate & politics of disease What is climate change? Projecting malaria & climate change Other determinants of disease Challenges ahead

36. Revisiting malaria & climate change predictions (x1000 excess deaths) Source: Tol & Dowlatabadi (2000)

37. Challenges in projecting future conditions • Today’s climate-malaria prevalence models are calibrated to regions with endemic malaria. These are not suitable for assessment of the malaria transition other regions. • Will there be far-reaching technological advances? • Where people prosper will they devote resources to fighting malaria? • Where malaria is the social norm, how might it become socially compatible to fight it? What about the reverse?.

38. Outline of this talk Background on climate and disease Climate & politics of disease What is climate change? Projecting malaria & climate change Other determinants of disease Challenges ahead

39. Projections of global change are fraught with uncertainty • We have trouble projecting socio-economic changes. HIV-AIDS, fall of the Soviet Block, miracle and faltering of the Asian Tigers. • We have trouble projecting how the climate system will react to human induced changes? H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, H2O, CO2, CO2, CO2, CO2, CO2, CO2, CO2, CO2, CO2, CO2, N2O, N2O,O3, O3,CFCs,All else.

40. Summary • Climate change can impact health outcomes through many pathways. • Nevertheless, demographic, socio-economic, technological and political factors are more important than climate in public health outcomes over the next century. • Non-climate factors change more rapidly and are generally easier to manipulate than the climate system. • A poorly designed climate policy will do more harm than good. • We are ill equipped to address key global public health challenges in the years ahead.