Human Health Impacts of Global Warming: A Literature Review
Global warming has been associated with various environmental outcomes across the world, particularly in the continuously industrialized world. The present essay explored the potential impacts of global warming on health. The findings showed that global warming has and continues to result in several negative impacts on health including increased prevalence of heat stress, increased prevalence of cancers and cataracts, change in infectious disease ecologies and patterns of spread and malnutrition due to impacts on food production. It is recommended that human activities should be used as drivers towards change in global warming.
One of the major global issues of the contemporary times is the phenomenon of global warming. Many concerns have been raised regarding the impacts of global warming on various environmental characteristics. While there are already identified effects of global warming, the scope of their impacts on human health is still underestimated. It is, however, reported that the anticipated impacts of global warming on human health will not be localized. Rather, they will occur within a worldwide scope, impinging entire populations and affecting people in large scale. The health consequences are predicted to be the result of a combination of direct effects of climate change such as extreme weather events and indirect impacts of climate change such as imbalances in the natural systems (Phelps, 1996). The indirect impacts would result in changes in aspects such as the ecology of infectious diseases, fresh water supply quantity and qualities, and food production. Forecasting the risks of human health impacts can be challenging due the uncertainty, complexity, and temporally expansive task of global warming exploration. In this context, the ensuing literature review explores specific health impacts of global warming as predicted from past literature.
Impacts of Global Warming on Human Health
According to Phelps (1996), the impacts of global warming on human health are projected to be severe and unprecedented. Changes in disease ecology and access to resources are at the center of the human health impacts of global warming. Phelps (1996) mentions infectious diseases as one of the expected health outcomes of global warming. While expounding on the concept of infectious diseases and global warming, Phelps asserts that the climate influences the severity, frequency, and type of infectious diseases differently. Vector-borne and non-vector-borne infectious diseases result from interactions between the climatic conditions and the infectious organisms that transmit those diseases. The interactions between the human host and the disease vector results in human infections. Climate change results in a heightened probability of contact between the disease vectors and the humans hence increasing the probability of infection. Similarly, climatic conditions such as temperature and rainfall affect the abundance and distribution of disease vectors, particularly insects and animals. The Union of Concerned Scientists (2018) posits that the distribution of animals and insects such as mosquitoes and ticks depends on the weather conditions, which increase the transmission of vector borne diseases. These studies provide confirmation that the increasing prevalence of infectious diseases can be attributed to global warming.
Besides infectious diseases, Patz and Thomson (2018) discuss the role of global warming in the increase of heat stress. The Interagency Working Group on Climate Change and Health (2010) posited that with global warming, the increase in the average temperature results in an increase in the frequency and severity of heat waves in some areas. The topics are particularly affected by such heat waves, which increase the frequency of illness and death. Among the young children, the ill, elderly, and the frail, the combination of heat stress and urban environments can result in death. Franchini and Mannucci (2015) aver that climate change can exacerbate the heat island effect that is common in large urban areas, increasing the frequency of heat- related mortality. Therefore, heat related mortality is considered as the largest direct threat to human health because of climate change. Phelps (1996) describes a phenomenon in which a heat wave resulted in the death of 726 people in the city of Chicago in the 1995 summer. This example also serves to indicate the possibilities in case the projected climate change scenarios for the coming years are accurate.
Other health effects of global warming include cataracts, skin cancer, and immune suppression. In a paper by Hathaway and Maibach (2018), the increasing prevalence of cancer across the world is cited as a possible direct impact of global warming. Factors such as changing diets because of changing food production patterns as well as the impacts of direct heat on human body have also been mentioned as some of the reasons for increasing prevalence of the mentioned impacts. According to Phelps (1996), the direct and indirect effects of the ozone depletion on ecological systems can be associated with the impacts on human health. This argument is supported by the Union of Concerned Scientists (2018), who report that the increased exposure of humans to ultraviolet radiation due to ozone depletion, as well as the dependence of the photosynthesis process on sunlight, can be blamed for the increasing prevalence of cancer and other diseases. The changes in available sunlight for photosynthesis affect the food production process, as photosynthesis is the main route for conversion of light energy to chemical energy. Direct human contact with the UV light rays results in conditions such as skin cancer, particularly non-melanoma types. Phelps (1996) reports that in the U.S, such skin cancers are already a major problem and evidence shows that there is a two percent increase in cancer prevalence for every percent decrease in the size of the stratospheric zone.
The most prevalent impact of global warming as discussed by various authors is the change in food production and nutritional health. Climate changes have varied impacts on food production because of the diverse outcomes of climate change. For instance, the tropical and subtropical regions experience prolonged droughts, flooding, and the appearance of new plant diseases and pests, which affect food production negatively. Luber and Prudent (2009) suggested that in other regions, there is a possibility of increase in food production because of higher temperatures. Those in higher temperature latitudes such as Canada, Patagonia, and Siberia could experience higher productivity (Phelps, 1996). With such changes in food productivity, nutritional disease patterns are also likely to change. Phelps reported that more than 800 million people are chronically undernourished and with increasing growth in population, this number is expected to increase even further. Luber and Prudent (2009) further suggest that the remedy to undernourishment could lie in changing crops, the diets, and planting practices to reduce vulnerability to food productivity effects of global warming.
Global warming has been extensively studied on the concept of its impacts on various aspects of life. From the weather, availability of fresh water, and food productivity, global warming has extended its impacts onto human health either directly or indirectly. The literature review has shown some of the contemporary and projected impacts of global warming, including outcomes such as increased prevalence of infectious diseases, and exacerbating heat stress, increased prevalence of health conditions such as cancer, cataracts, and various skin conditions. Additionally, nutritional impacts on human health have also been mentioned. This review provides a basis for additional studies on the reduction of global warming. From the thesis that global warming is a result of human activity, it is clear that averting the consequences of global warming would require direct attacks at the root of the problem, which is through behavioral changes to reduce global warming.
Franchini, M. & Mannucci, P.M. (2015). Impact on human health of climate changes. European Journal of Internal Medicine, 26(1), 1-5. Retrieved from www.ejinme.com/article/S0953-6205(14)00362-8/fulltext
Hathaway, J. & Maibach, E.W. (2018). Health implications of climate change: A review of the literature about the perception of the public and health professionals. Current Environmental Health Reports, 5(1), 197-204. Retrieved from www.ncbi.nlm.nih.gov/pmc/articles/PMC5876339/
Interagency Working Group on Climate Change and Health (2010). A human health perspective on climate change: A report outlining the research needs on the human health effects of climate change. Environmental Health perspectives and the National Institute of Environmental Health Sciences. Retrieved from www.niehs.nih.gov/health/materials/a_human_health_perspective_on_climate_change_full_report_508.pdf
Luber, G. & Prudent, N. (2009). Climate change and human health. Transactions of the American Clinical and Climatological Association, 120, 113-117. Retrieved from www.ncbi.nlm.nih.gov/pmc/articles/PMC2744549/
Patz, J. & Thomson, M.C. (2018). Climate change and health: Moving from theory to practice. PLoS Medicine, 15(7). Retrieved from journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1002628
Phelps, F.B. (1996). Potential human health effects of global climate change. In Setlow, V. & Pope, A. (Eds.), Conference on Human Health and Global Climate Change: Summary of the Proceedings. Washington, DC: National Academies Press (US). Retrieved from www.ncbi.nlm.nih.gov/books/NBK231171/
Union of Concerned Scientists (2018). Global warming impacts. Union of Concerned Scientists. Retrieved from www.ucsusa.org/our-work/global-warming/science-and-impacts/global-warming-impacts#.XAfylc1RXIU