Environmental Effects of Global Warming
The greenhouse effect and global warming are issues that are talked about by geologists all the time. The greenhouse effect is a natural process that keeps the earth at temperatures that are livable. Energy from the sun warms the earth when its heat rays are absorbed by greenhouse gasses and become trapped in the atmosphere. Some of the most common greenhouse gasses are water vapor, carbon dioxide, and methane. If there were no greenhouse gasses, very few rays would be absorbed and the earth would be extremely cold. When too many rays are absorbed, the earth’s atmosphere starts to warm, which leads to global warming. Global warming can lead to many problems that affects the environment in which we live.
In order to talk about global warming, we must first learn what causes the greenhouse effect. A lot of the rays from the sun are absorbed by water vapor that is naturally in our atmosphere. Water vapor accounts for “80 percent of natural greenhouse warming. The remaining 20 percent is due to other gasses that are present in very small amounts1”. Carbon dioxide is also a big absorber of the sun’s heat rays. Humans can cause a lot of carbon dioxide to be released. Every time we burn fossil fuels, we release more carbon dioxide. Emissions from cars also increase the amount of carbon dioxide in the atmosphere. If there is more carbon dioxide in the atmosphere more rays from the sun are absorbed. This will cause the atmosphere and the earth’s temperature to warm. The warming of the earth will cause the oceans to become warmer. When they heat up, more water is evaporated, causing more carbon dioxide to be released into the atmosphere. Once this process starts, it is extremely hard to control. If the temperature keeps rising, more carbon dioxide will be released.
Another greenhouse gas is methane: “Methane absorbs infrared radiation 25 times more effectively than carbon dioxide, making it an important greenhouse gas despite its relatively low concentration2”. There have been many studies on how methane is released into the atmosphere. Methane in the atmosphere is “generated by biological activity related to rice cultivation, leaks in domestic and industrial gaslines, and the digestive process of domestic livestock, especially cattle3”.
An environmental effect of global warming is the fact that higher temperatures will lead to a change in the water cycle. Some places may experience more rain. Warmer temperatures will cause a greater amount of evaporation from lakes, rivers, and oceans. In some areas this could be good, and in others it could be considered bad. In northern regions of the United States, an increase in the temperature and amount of rain could actually extend the growing season of crops. This would in turn mean more money for farmers in the northern region. It could also hurt some farmers. Too much rain is bad for some crops. Certain areas will actually get less rain, which would lead to more droughts and have a negative impact on crops. Warm and wet weather is usually a factor that promotes tropical storms. Global warming would lead to tropical storms’ appearing with greater frequency. More rain will also force plant life to adjust. Forests and plant life migrate naturally, but scientists say that global warming would cause them to migrate at a much faster rate. If the climate changes the Intergovernmental Panel on Climate Change says, “some forest species in North America will shift by as much as 300 miles to the north4”. If a region is getting more rain and plants on the border of that region need rain to survive, they will naturally begin growing in the new region.
The Environmental Media Services Organization has found that the greenhouse effect “could drive global temperatures up as much as 6 degrees by the year 2100 – an increase in heat comparable to the 10 degree warming that ended the last ice age5”. If a ten degree warming was the factor that ended the ice age, imagine what another warming by about that same amount could do. Scientists believe that a warming of only 6 degrees would cause glaciers to melt at a high rate. This would cause an increase in the level of the oceans. According to the article “Turning up the Heat: How Global Warming Threatens Life in the Sea,” coastal cities and islands would be in danger of flooding if the ocean levels rose: “Only a 1-cm rise in sea level can erode a full 1 meter of beach6”. Sea ice would also be susceptible to melting, which would raise the water level even more.
Global warming will not just make sea levels rise, it will also affect sea life. Corals “are intolerant of temperatures just a few degrees warmer than usual7”. Small increases in the temperature can kill corals. There have been problems with corals dying in the past few years because of increased water temperatures. Other marine life may migrate northward or southward because the waters are warmer. The warm water would make them think that they were in their natural habitat, when they were actually migrating toward the poles. Food would be scarce in their new habitat.
Patterns of the circulation of sea water are disturbed by global warming. Cold water moves along the sea floor towards the equator and warm water around the equator moves toward the poles across the surface of the ocean. It is known as thermohaline circulation. It is a very important process concerning ocean life. This circulation process brings oxygenated water to the sea floor. If this did not happen, “water along the sea floor would become depleted of the oxygen organisms need to survive8”.
Fish, such as salmon, are also sensitive to the temperature of the water. During the summer when the water is warm, salmon have a higher metabolic rate. During the winter months, their metabolism slows down, which is good because less food is available. With global warming and increased water temperatures, salmon would have a higher metabolic rate, even if it were during the winter. Less food would be available for them and many salmon would die.
Another impact of global warming will be that some diseases are likely to be spread more easily. Mosquitoes are a major carrier of tropical diseases. They are commonly known for carrying malaria, cholera, and dengue fever. Malaria outbreaks are usually confined to “where the minimum winter temperature reaches no lower than 16 degrees Celsius,” according to the World Wide Fund for Nature, an independent conservation organization9. Scientists are beginning to notice that malaria outbreaks are occurring outside these places. They are attributing this to increased temperatures from global warming. Places such as California, Texas, Florida, Michigan, and New York have had more cases of malaria. People from these states know that the summers have been very hot and humid lately. Malaria mosquitoes thrive in hot and humid weather. Increased temperatures and more rain in some areas will cause hot and humid weather, which will allow for mosquitoes to migrate to new places and spread the disease. A study suggests that “malaria transmission would increase from 45% of the globe to 60%, if atmospheric levels of greenhouse gases reach concentrations equivalent to a doubling of CO2 since the industrial revolution10”. Cholera and dengue fever are also carried by mosquitoes and thrive in warm and moist climates. As with malaria, more cholera and dengue fever outbreaks would occur because of migrating mosquitoes.
As stated earlier, the warming of the oceans will increase the amount of carbon dioxide in the atmosphere and will make global warming a problem of increasing severity. There are other ways that this happens too. As the weather becomes warmer, more organic matter in the ground will be decomposed. This causes carbon dioxide to be released into the atmosphere: “If average temperatures would rise by .3 degrees C per decade, soils will release an amount of CO2 equal to nearly 20 percent of the projected amount released by combustion of fossil fuels11”. Gas hydrates will also decompose with warmer temperatures. Gas hydrates are “icelike solids in which molecules of gas, mainly methane, are locked in the structure of water” and are usually found in frozen soil or in ocean sediments12. Scientists have found that “gas hydrates worldwide hold a total of 10,000 billion metric tons of carbon, twice the amount contained in all the known coal, gas, and oil reserves on the land13”. When temperatures increase, frozen soil will melt and release gas hydrates, and hydrates from ocean sediment will also break down. Because of this, more methane and carbon will be released into the atmosphere, making the greenhouse effect even stronger. This will damage our environment even more.
Global warming is becoming a major problem as we move to the 21st century and beyond. When more greenhouse gasses like carbon dioxide and methane are released, they trap heat rays and keep them in our atmosphere. This causes an increase in temperature. Increases in temperature can do a lot of damage, even in small increases. Only a few degrees ended the ice age thousands of years ago. Another warming like that can have huge environmental effects. Changes in temperature will upset water cycles. Some areas will get more precipitation, some will get less. A warming of a few degrees would cause glaciers and sea ice to melt. This would lead to ocean levels rising and would damage coastal cities and islands. It would also cause a disruption in different species living in the ocean and increase the levels of some disease, especially ones carried by mosquitoes, which thrive in warm climates. In order to stop global warming, much has to be done. Although it is very difficult to reverse once the process is started, global warming has to be stopped if we want to live like we are now. Emission of fossil fuels by humans is a big factor in the amount of carbon dioxide in the atmosphere. Controlling these emissions is one of the first of many steps that we must take in order to combat global warming. If it is not controlled, problems such as the aforementioned ones, along with others, will definitely disrupt our living patterns.
1 Murck, Skinner and Porter (488)
2 Murck, Skinner and Porter (490)
3 Murck, Skinner and Porter (490)
6 Berntson and Mathews-Amos www.worldwildelife.org/news/pups/wwf_ocean.htm
11 Murck, Skinner and Porter (495)
12 Murck, Skinner and Porter (495)
13 Murck, Skinner and Porter (495)
Berntson, Ewann, “Turning up the Heat: How Global Warming Threatens Life in the Sea.” World Wildelife Fund and the Marine Conservation Biology Institute. 3 Aug. 2000 <www.worldwildelife.org/news/pups/wwf_ocean.htm>.
“Fast Facts” 1999. Environmental Media Services. 3 Aug. 2000 <www.ems.org/climate/sub2_html>.
“Malaria and Dengue Fever” World Wildlife Fund for Nature. 3 Aug. 2000 <www.panda.org/climate/climate_docs/health_factsheet/malria.htm>.
Murck, Barbara, Brian Skinner, and Stephen Porter. Environmental Geology. New York: John Wiley & Sons, Inc., 1996.
“Stop Global Warming.” Mar. 1999. Public Intrest Research Groups. 3 Aug. 2000 <www.pirg.org/enviro/global_w/fact.htm>.