Global Warmings Affect on Human Health

Throughout the world, the presence of particular diseases and other threats to human health depend largely on the local climate. Extreme variations in temperature can directly, and indirectly, cause the loss of human life. The threat of a gradual increase in temperature could be catastrophic to the world as we know it. As recently as 1999, a heat wave killed more than 250 people in Chicago (Union of Concerned Scientists). Many wrote off the event as a natural disaster. However, scientists warn that the average global temperature has increased 0.5o F in the past 40 years. This is half of the total increase in surface temperature, 1o F, since the late 19th century. At its current rate, the global temperature could rise 2o to 6o F in the next 100 years (Union of Concerned Scientist).

Such a drastic increase in the rate of temperature is due to the industrial revolution. In the past 40 years the world has seen a dramatic rise in population, which has increased our use of fossil fuels (gasoline, oil, coal or natural gas). These fuels are used to run our cars, heat and cool our homes, manufacture goods in our factories and ship these items for worldwide consumption. The focus, until lately, has been to produce maximum product at a minimum price to maximize profit. Little to no care was taken to minimize the amount of fossil fuels used in the production of goods. Recently, it has become evident that such practices lead to the production of greenhouse gases. Whenever fossil fuels are burned for energy, greenhouse gases, such as carbon dioxide builds up in the earth's atmosphere (Union of Concerned Scientists).

Another reason why greenhouse gases have increased is due to the decrease in the amount of plant life, commonly called deforestation. Plant life is the only thing known on earth to consume carbon dioxide. However, due to the need of raw materials (wood and paper pulp), industrial nations tend to cut down more trees than they can reforest (Fuller 454). Also, toxins produced as a by-product of industrialization have killed plant life. Therefore, a greater amount of carbon dioxide is being produced at the same time less carbon dioxide is being consumed, leading to dangerous consequences.

The combination of pollutants and deforestation has led to what is commonly called the Greenhouse Effect. The term "Greenhouse Effect" comes from the understanding that pollutants thickening the earth's atmosphere keep heat trapped in the atmosphere. Thereby leading to an increase in the earth's temperature, or Global Warming. Although, a increase of a few degrees over hundreds of years doesn't seem like much to some people, the variance is great enough to allow some deadly bacteria to thrive and disease to spread. Moreover, warmer temperatures can increase air and water pollution, which could harm human health.

In the past few years, there has been an increasing amount of reports that correspond with these theories. Worldwide, there have been reports of cases indicating a spread of mosquito-born infectious disease, heat stroke and asthma / respiratory disease. It is believed that the 1o F change in average global temperature has much to do with the deterioration of human health.

For example, there are an increasing number of reports of mosquito-born, infectious disease in areas that have not been previously exposed. Such cases include a malaria outbreak in the summer of 1997 in the Kenyan highlands and a spread of dengue and yellow fever in the Andes Mountain of Colombia, previously limited to below 3,300 feet, is now seen as high as 5,600 feet (Union of Concerned Scientists). Many countries from Tanzania and Indonesia, to as close as Mexico, have also reported outbreaks of such infectious disease. The outbreaks are a result of an increase of temperature in areas that mosquitoes previously could not breed. The populations of these areas are also more susceptible to these diseases because the disease is foreign to their immune systems. A lack of natural enemies in such areas also allows the mosquito population to grow more quickly. The result in Kenya was the death of hundreds of people.

Rodents also thrive in warm weather. In the case of unusually mild winter weather in Australia in 1993, and again in 1994, the breeding season for rodents and insects was extended; then a wet summer and a long, mild autumn increased the food supply for these pests. In July 1993, mice ravaged crops in south Australia, costing farmers $100 million (Leggett, 115). In the worst hit areas, there were more than 100 mice per square meter, approximately a square yard. Fortunately, the lose of money was greater than the lose of life in Australia. Such an infestation could have brought a wave of rodent borne diseases.

The past few years have brought record heat to many parts of the world, including the United States. Southern Africa has reported 1985-1995