Global Environmental Change: We are all in it Together!!

With an increase in globalization and urbanization, comes a wide array of problems. Human activity has exponentially increased the effects of global warming on the environment and on the health of not only human beings, but all living creatures. “Together, global warming, population growth, habitat destruction, and resource depletion have produced a widely acknowledged environmental crisis” (McCally 2002). Furthermore, this environmental crisis is no longer concentrated on the local level; rather, it is a global problem that can only be dealt with through a collective and global effort. These global changes produce human health effects, some of which are difficult to assess and some of which are easily apparent.
Global warming—one of the greatest contributions to the current deterioration of the earth and it’s living things. What is causing global warming? The answer to this question is extremely complex. One main reason is the accumulation of green house gas and the depletion of the ozone layer. One of the articles this week states “The unusually rapid temperature rise (0.5°C) since the mid-1970s is substantially attributable to this anthropogenic increase in greenhouse gases” (McMichael et al 2006). Although low concentrations of greenhouse gas emissions are natural (in order to keep the earth from freezing), since the rise of industrialization, greenhouse gas emissions have increased exponentially. Combustion of fossil fuels, irrigated agriculture, deforestation, and cement manufacture are just some of the human activities that contribute to the rise in concentration of greenhouse gases (Houghton et al 1996). The three main greenhouse gases include: carbon dioxide, methane, and nitrous oxide, each of which have been extensively researched and have direct negative impacts on human health. The concentrations of these particular greenhouse gases have dramatically increased and have reached their highest levels over that last millennium (Albritton et al 2001). With this increase, comes the rise in overall global temperature and radical climate change. Consequences of this climate change include an increase in heavy rain events and prolonged droughts. Some of the direct effects on human health due to changes in temperature and weather include: changes in the rate of illness and death due to heat and cold and an increase in deaths/injuries/psychological disorders due to the change in frequency and intensity of extreme weather events. From lecture, it is apparent that the number of extreme-heat events (such as heat waves) have increased with the twelve-day heat wave of August 2003 in Europe being a prime example. The number of deaths due to this heat wave were staggering, with about 15,000 deaths in France alone and 35,000 deaths total (Lecture 2009, McMicheal 2006). This is particularly important for vulnerable populations such as the elderly, young children, athletes, and people who spend most of their time outdoors. Beyond these direct effects, there are several indirect effects of climate change, which have negative impact on health. One in particular is the rise in sea-level, which causes population displacement and damage to infrastructure, which ultimately increases the risk for infectious disease and psychological disorders. The increase in air pollution exacerbates asthma and other respiratory illnesses, which ultimately leads to premature death. Furthermore, there is a large pressure put on ecological systems, which change the activities of vectors/infective parasites thus increasing the incidence of vector-borne disease. These are just some of the indirect effects and ultimately all of these effects put a strain on the health care system and public health infrastructure, leading to inadequate care of infectious diseases, water-borne/food-borne diseases, and psychological disorders. (McMicheal and Haines 1997).
Ozone depletion is another consequence of global warming. In 1974, a group of prominent scientists (Molina, Rowland, and Crutzen) found that “ozone might be destroyed by industrially produced chlorine- and bromine-containing stable substances, such as chlorofluorocarbons (CFCs) commonly used in spray cans, refrigerators, and air-conditioners” (Molina et al 1974). This accumulation of CFCs and other industrial activities has contributed to the “ozone hole”, which is increased the influx of UV radiation at the earth’s surface and in the top layers of the ocean (de Gruijl and Van der Leun 1994). The direct impact of an increase in UV radiation on human health is the increase in cancers, especially skin cancer. A one-percent decrease in ozone yields a 1.56% increase in annual carcinogenic UV (Kelfkens et al. 2008). Beyond cancer, increased UV radiation is known to increase the incidence of cataracts. Scientists have estimated that the incidence of cataracts would ultimately rise by 0.5 percent for every 1 percent persistent decrease in ozone (Van der Leun et al. 1993). In addition to this human impact, the productivity of phytoplankton was found to be reduced by 6 to 12 percent directly under the ozone hole (Smith et al. 1992). These kind of effects on organisms at the bottom of the marine food chain will ultimately impact larger marine animals, and eventually humans.
Beyond the accumulation of greenhouse effects and ozone depletion, habitat destruction is another human activity that contributes to the changing environment. With habitat destruction comes the destruction and extinction of microorganisms, plants, animals, and other living things in addition to the detectable air pollution of burning forests. The additive effect of global climate change, ozone depletion, chemical pollution, acid rain, and the extinction of species all threaten biodiversity (Chivian 2001). Rainforests and coral reefs continue to be disrupted and with the decrease in biodiversity will come a detrimental effect of the world’s ecosystem. Biodiversity is the total complement of different living organisms in an environment and the destruction of it will lead to detrimental consequences for human health. In lecture, ecotourism was discussed, which is defined as “responsible travel to natural areas that conserves the environment and improves the well-being of local people” (Lecture 2009). Ecotourism is a prime example of how human activity is destructing natural habitats. With an increase of human contact with natural rain forests/coral reefs/other habitats, comes an introduction of new pathogens, particulate matter, diseases/viruses, which threatens the life of plants, natural bacteria, and ultimately all of the living organisms in that particular habitat. In some extreme cases, species who are exposed to various human activity and pollution have immediately become extinct. On the other hand, ecotourism helps the economy of the local people and raises awareness of the importance of environment conservation (many tourists donate money). Therefore, there must be a balance between human activity and helping the economy. If the problem of habitat destruction is not dealt with, soon enough, mass extinctions of species will ultimately affect the health of humans.
How can all these problems be fixed? The answer is that they cannot be, however, the process of environmental change can be slowed down. If current trends persist, climate change will be exponential which will ultimately endanger the health and lives of not only humans, but all living organisms. The first step that should be taken is to slow down or stop environmental degradation by implementing strict policies on air pollution (from combustion of fossil fuels, medical waste incineration, factory emissions, agriculture, etc.) and habitat destruction. The second step that needs to be taken is to achieve a collective effort (especially between developed and developing countries). Since these environmental changes are a global problem, a global initiative is needed. With aid from developed countries, developing countries will gain the required education, training, and technologies to effectively reduce environmental degradation. The last step that should be taken is to develop long-term educational strategies that will change the mindsets of individuals and institutions with respect to protecting the environment and promoting health. (McCally 2002)


References
Albritton DI, Allen MR, Baede APM, et al., eds. Intergovernmental Panel on Climate Change Working Group I. Summary for Policy Makers, Third Assessment Report. Climate change 2001: The Scientific Basis. Geneva, 2001.

Chivian E. Environment and health: 7. Species loss and ecosystem disruption—The implications for human health. CMAJ 2001; 164: 66-69.

De Gruijl FR, Van der Leun JC. Estimate of the wavelength dependency of ultraviolet carcinogenesis in humans and its relevance to the risk assessment of stratospheric ozone depletion. Health Phys 1994; 67: 319-325.

Houghton JT, Meira-Filho LG, Callander BA, Harris N, Kattenberg A, Maskell K, editors. Climate change, 1995—the science of climate change: Contributions of Working Group 1 to the second assessment report of the Intergovernmental Panel on Climate Change. New York: Cambridge University Press, 1996.

McCally M. Life support: The environment and human health. Cambridge, Massachusetts: MIT press, 2002.

McMicheal AJ, Haines A. Global climate change: The potential effects on health. BMJ 1997; 315:805-809.

McMicheal AJ, Ranmuthugala G. Global Climate Change and Human Health. IN:Kawachi I, Wamala S, eds. Globalization and Health. New York: Oxford University Press; 2006: 81-97.

Molina MJ, Rowland FS. Stratospheric sink for chlorofluoromethanes: Chlorine atom-catalyzed destruction of ozone. Nature 1974; 249: 810-812.

Smith RC, Prezelin BB, Baker KS, Bidigare RR, Boucher NP, Coley T, et al. Ozone depletion: Ultraviolet radiation and phytoplankton biology in Antarctic waters. Science 1992; 255: 893-1040.

Van der Leun JC, De Grujil FR. Influence of ozone depletion on human health. In: Tevini M, editor. UV-B radiation and ozone depletion. Boca Raton, FL: Lewis Publishers, 1993. Pp.95-123.