Pre-Class Preparation Pre-Class Preparation
Objectives
Class images
 | Climate change scenarios: The possible health effects. (From UNEP.) |
| Eddy, John A., ed, 1997: Consequences: The Nature & Implications of Environmental Change (3)2. (From GCRIO.) |
Class Discussion
Summary Prepared by: Nathan Ohrt, Kurtis Cecil, Daniel Pollock, and Lori SchmitzSummary of in class discussion:
It was mentioned that the article on line was from a researcher at Harvard. It was also mentioned that Foot and Mouth disease is a good example of the global nature of epidemics and may be used as a model for human epidemics. Not much else was mentioned on this topic area, because more time was spent on the global population topic.
Online discussion:
One question brought up was, are there was any diseases around today that were linked to global warming. It was decided that skin cancer would be one of these since more UV light would reach the earth's surface as a result of ozone depletion.
Another issue brought up was that people in the future may sue other nations in the World Court of the United Nations for putting CO2 into the air.
One topic addressed was we need to consider mosquitos and milaria if we are going to be restoring wetlands.
And the final topic brought up was on the increase of certain generalist animals like crows and geese. Some ideas of why there were so many around was the milder winters and more food. It was also asked why geese were not scared off by humans, and was decided that they didn't because they did not fear for their lives. It was thought that the geese come back, because that is where they remember there was food.
Summary of Class Readings:
Diseases are found to spread more in times of change then times of stability. With changing states of climate, declining species numbers, and increasing differences in economic levels, greater cases of diseases are spreading on regional and worldly scales. Warming may provide a good environment for vegetation, but also creates a favorable environment for microbes, their carriers, and other changes in weather.
Pandemics are widespread diseases that effect multiple continents. Some of these widespread diseases that we are still dealing with include: Drug-resistant tuberculosis, made worse by HIV/AIDS, childhood diphtheria, whooping cough, measles, malaria, dengue, yellow fever, cholera, and rodent-borne viruses.
In the past, pandemics have often been associated with major social changes and overtaxed society. Their effects sometimes lead to sanitary and environmental reform movements. In the 1970's attention was turned to chronic diseases, with the belief that such past diseases were dying out. The belief was that health was in a time of "epidemiological transition". But drug resistant bacteria and other microbes fought back as a result of antibiotics and insecticides.
Malaria which dropped off in the 50's, started to reemerge the 70's with declining health programs, insecticide resistance, and land changes. With increasing temperatures in the 80's the disease grew even more. This is just one of the many ways ecosystem and weather/climate changes have shown to have an important role on the spread of disease.
Climate effects the range, timing, and intensity of vector-borne diseases. Insect biting and development of microorganisms depend on temperature, as they increase with warmer temperatures until they hit a certain point where the temperature gets too hot. Various changes in climate can make certain environments more favorable to disease. Floods spread bacteria, viruses, and chemicals, while promoting the growth of fungi, and the insect populations. Long droughts, intermixed with heavy rains, favor population explosions of both insects and rodents.
In stressed environments opportunists such as weeds, rodents, insects, and microorganisms thrive. This is a result of loss of predators that keep such animals in check. Conditions that lead to this include: Fragmentation of environments, monoculture systems, overuse of toxic chemicals, increased ultraviolet radiation, and climate/weather change. The loss of opportunistic predators through species extinction causes threats to human health, because opportunists help to spread infectious diseases.
Some other indicators of a stressed environments include; emerging infectious diseases, dominance of generalist species that have wide-ranging diets over specialist species, and in aquatic environments the proliferation of harmful algal blooms.
Sea Coasts are under increasing stress as a result of pressure from residential, recreational, and commercial development. Such stresses include excess dissolved mineral and organic nutrients, less wetlands, overfishing, increases in chemical pollution an UV-B radiation, and the warming of coastal waters. This stress in the sea, allows for opportunistic pathogens to thrive, just like on land. One example of this is cholera.
Surface temperatures of the ocean have warmed this century, and evidence of a gradual warming of the deep ocean has been found in recent oceanographic surveys. Increased temperatures on water and land increases water cycling, humidity, and the greenhouse effect. Warm waters also help produce tropical storms. With the right amount of nutrients present warming of the ocean may help in algal production. Some algal blooms are toxic.
The natural world, including climate, has shown to change quickly as well as stay at equilibrium states. More extreme swings is inversely related to how stable the systems are and their sensitivity to change. Poorer populations are at greatest disease risk but with today's movement diseases are more easily spread to developed nations, as well. The economic impacts of disease in humans, livestock, and food crops can be severe and widespread. Steps that need to be taken include improved surveillance and response from the public health sector, along with considering health consequence when looking at the results of monitoring the environment and making environmental and energy decisions. Land use and fossil fuel also need to be considered when looking at biodiversity, climate, and diseases. By breaking our dependence on fossil fuels we may help produce a healthier and more productive future.
Post-Class Activities
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Spread of major vector-borne
diseases |
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Potential dengue
transmission in case of temperature rise |
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Spread of malaria
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| CIESIN Thematic Guide: Health Effects from Increased Exposure to Ultraviolet-B (UV-B) Radiation due to Stratospheric Ozone Depletion |
| CIESIN Thematic Guide: Human Health and Global Change |
| Climate, Ecology and Human Health, from Consequences Magazine |
| Evidence of Climate Connections to the Return of Infectious Diseases. |
| Global total of countries reporting incidences of infectious diseases. |
| Global Warming and Infectious Disease. |
| Human Activities that are Affecting Global Climate Change: EPA Report on Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-94 |
| Pamphlets and Press Releases from the American Academy of Dermatology. |
| UV Index and Sun protection. |
| Jeevan, A., and M. L. Kripke, 1993: Ozone Depletion and the Immune System. The Lancet, 342, 1159-1160. |
 | Guidelines on Ozone Monitoring Site Selection, EPA. (pdf file) |
| Is Global Warming Harmful to Health? |
| Ozone Science: A Canadian Perspective |
| Environmental Health Perspectives |
| Melanoma Patients' Information Page |
| American Meteorology Society Journals |
| Malaria Foundation International |
| Wahlgren, Mats, and Qijun Chen, 2000: Special focus on malaria. Nature 406 No.6794 (July 27). |
| Dye, C. and
P. Reiter, 2000: Temperatures without fevers? Science
289, 1697-1698. |
| Rogers, D.
J. and S. E. Randolph, 2000: The global spread of malaria in a future, warmer
world. Science 289, 1763-1766. |
| Pascual, M.,
X. Rodo, S. P. Ellner, R. Colwell, and M. J. Bouma,
2000: Cholera dynamics and El Nino-Southern Oscillation. Science
289, 1766-1769. |
| Patz, J. A., M. A. McGeehin, S. M. Bernard, K. L. Ebi, P. R. Epstein, A. Grambsch, D. J. Gubler, P. Reiter, I. Romieu, J. B. Rose, J. M. Samet, and J. Trtanj, 2000: The potential health impacts of climate varibility and change for the United States: Executive summary of the report of the health sector of the U.S. National Assessment. Environmental Health Perspectives 108, 367-376. |
| Patz, Jonathan A., Paul R. Epstein, Thomas A. Burke, and John M. Balbus, 1996: Global Climate Change and Emerging Infectious Diseases. Journal of American Medical Association 275, 217-223. |
| Stanford, J. L. and J. R. Ziemke, 1996: A Practical Method for Predicting Midlatitude Total Column Ozone From Operational Forecast Temperature. Journal of Geophysical Research, 101, 28,769-28,773. |
| Stanford, J. L., J. R. Ziemke, R. D. McPeters, A. J. Krueger, and P. K. Bhartia, 1995: Spectral Analyses, Climatology, and Interannual Variability of Nimbus-7 TOMS Version 6 Total Column Ozone. NASA Reference Publication 1360, April, 80 pp. |
| Wendler, G., and T. Quakenbush, 1996: UV radiation in the southern seas inearly spring 1993. Theoretical and Applied Climatology 53, 221-230. |