Global Warming and Vector-Born Disease
Factors Contributing to Global Warming
There has been an unequivocal and ongoing increase in the earth’s average temperature in a phenomenon termed as global warming. Scientists describe global warming as the unequivocal rise in the average temperature in the sea, air and the earth’s surface. Such climb in warmth occurs due to the greenhouse effect caused by greenhouse gases. These gases act as a blanket that traps radiating heat, hence, warming the earth (Patz & Olson, 2006, pp. 535).
The greenhouse gases responsible for global warming are released mostly by humans and their activities in a number of ways. Most of these gases are released, as the outcome of burning fossil fuels in vehicles and other heavy machinery in factories and industries. The most common gas released in these combustion reactions is carbon dioxide. From the onset of the twentieth century, humans have constantly increased the release of greenhouse gases by smoldering fossil energy, for instance, coal. When coal is burnt carbon reacts with oxygen forming carbon dioxide. Other sources of greenhouse gases include the clearing of forest for agricultural purposes and other human activities.
The effect of greenhouse gases is that the average temperature of the seas, land and atmosphere increases significantly. The resulting effect of this temperature difference is the increased evaporation of the polar caps and precipitation. Such effect differs from one region to the other. As a result, some regions become damper and some become drier.
Global Warming and the Incidence and Prevalence of the Disease
The adverse effects o global warming include the raised sea levels, as a result of melting of the polar ice caps, drought prevalence and alternating storm patterns. These global warming outcomes have been deliberated widely by scientists especially climatologists, but biologists have also waded into the debate. Biologists have added another dimension with devastating to this debate. In the recent past, there has been growing evidence that global warming can increase the occurrence and frequency of tropical illness such as malaria and dengue fever (Brower, 2001, pp. 757).
The increased prevalence and incidence of these diseases is primarily linked to the changing pattern of its vector, mosquitoes. The changes in the habitat of mosquitoes, either increase or decrease of temperature, affect their prevalence. According to Brower (2001, pp. 755), temperatures that exceed optimal in the mosquitoes habitat kill them. However, within their optimal temperature range, mosquitoes reproduce faster and bite more frequently as the air becomes warmer.
The changes in climate can also promote malaria and dengue vectors colonizing new habitats. Brower (2001, pp. 755), points out that since the beginning of the twentieth century, mosquitoes have started surviving in spells of hot weather in various states in America. In the studies conducted by the Associate Director of Center for Health and Global Environment at Harvard, Paul Epstein indicated that malaria has reemerged in Asia, Southern Europe and Russia. The disease has since spread to other regions such as America and the northern part of Australia in recent years (Brower, 2001, pp. 757). Brower states thaat global warming is the source of the spread of this vector borne disease.
Climate change, as a result of global warming, lengthens transmission spell for vector borne diseases, such as dengue hemorrhagic fever, and speeds up their development cycle within the vectors, thus, producing more transferable bites annualy (Brower, 2001, pp. 756). In arid places, lack of rain prompts the storage of water for drinking and thus increasing the development habitats for these vectors (Bangs & Subianto, 1999, pp. 611). On the other hand, the increased rainfall, as a result of climate change, expands vector populations by producing new breeding grounds.
The effects of climate change, as a result of global warming on vector borne diseases, can simply be attributed to the fact that most of these vectors are ectothermic, hence subjected to the effects of the changing environmental temperatures in their growth, replication and population dynamics (Gage et al., 2008, pp. 437). The availability and amount of rainfall in the area can strongly manipulate the survival of disease vectors. It is in terms of availability of breeding sites for vectors that have aquatic immature stages.
Global warming has resulted in climate change that has significantly affected the prevalence and incidence of vector borne diseases among humans. The aspects of weather, such as temperature, humidity and rainfall, affect the reproductive, development and populace dynamics of mosquito vectors (Gage et al., 2008, pp. 437). The development of disease causing pathogens in these vectors can also be affected by climate change.