Oceans in Danger

Water takes up a larger percentage of the surface of our Earth than does land. The earth's oceans are vital aspects to our environment and it is necessary that we take care of them. On another note, global warming is an issue that is having effects on almost all aspects of our environment. Global warming itself means a gradual increase in the temperature of our Earth's atmosphere over large periods of time. There is evidence that global warming has occurred in the atmosphere, however, now we are beginning to see its effects in the world's oceans, as well. Though some may not see the connection that it has with the oceans, it has had quite a profound effect on our Earth's oceans. As I mentioned before, oceans are environments that must maintain each characteristic in order to survive. If one aspect of the ocean becomes altered, it leads to many consequences.

Oceans are one of the most difficult areas to measure and take data from in our environment. However, we must first explore whether the oceans are actually being affected by global warming or not. Scientists have tried to use computerized models of our Earth's oceans in order to make predictions on global warming effects. Teams of oceanographers have also been compiling ocean temperature readings from 1948 to 1996 in the Atlantic, Indian, and Pacific oceans. The study done by this team came to the conclusion that ocean temperatures below 300 meters have been raised a tenth of a degree Fahrenheit since the 1950s. Also, closer to the surface, ocean waters have increased in temperature by about 0.5 degrees (Pawelski, 2000). The principal author of this study and chief of National Oceanic and Atmospheric Administration's Ocean Climate Laboratory, Sydney Levitus, said, "These temperature changes may seem small, but they represent very large changes in heat content of the ocean, and this heat will eventually find it its way back to the atmosphere." (Pawelski, 2000). Thus, although these temperature changes in the ocean seem small, they can have quite a large effect on our Earth's atmosphere. Levitus also mentions that a large portion of global warming that seems to be absent in our atmosphere is actually in our oceans. We have found the "missing warming" in our oceans and now it is necessary that we try to reduce it (Kerr, 2000). From Levitus' study alone and also from recent attempts to digitize ocean data, we realize that global warming actually does have quite an impact on our oceans.

Now that we are aware that global warming is influencing our world's oceans, we must look at the affects that it is having. I did not find any positive affects of global warming on the oceans. It is sad to say, but I was left with only the negative. One of the effects that warmer temperatures have on the oceans is that they disrupt the ocean circulation rate (Pearce, 1996). As I previously mentioned, oceans must maintain all of its characteristics properly. Warmer temperatures in the atmosphere affect circulation rates in the oceans. If circulation rates in the oceans are altered, then everything in the oceanic environment becomes changed. The oceanic currents become affected, as well.

Global warming is also affecting the animals that live in our marine environments. These marine mammals are accustomed to living in specific temperatures. They cannot survive in the water if the temperature of the water changes dramatically. Thus, certain animals die as a result of the increase in temperature of the oceans. Also, it is very difficult to receive data from something as large and profound as our oceans. The various techniques that scientists use to receive data are not exactly quiet experiments. The tools used to take ocean data are actually loud machines that are put into the ocean. One might think that these loud machines would have no affect on animals because it is very difficult to hear things under water. However, some of us do not think about what animals hear under water. Their perception of sound under water is greatly different than ours. For example, bottlenose dolphins have been tested to have a hearing range of frequencies from 200 to 150,000 hertz. On the other hand, humans only hear between 20 to 20,000 hertz (Preston, 1997). Certain sea creatures actually use sound for navigation and communication throughout the oceans. The effect that global warming research has on these animals is that we are slowly destroying their capabilities to hear so well (Preston, 1997). The machines that we use may not affect us, however, they are affecting the auditory senses of animals under water.

Global warming is dramatically increasing the temperature of our oceans. The Earth's oceans are very sensitive to the atmosphere. When changes in the atmosphere occur, so do changes in the water. The increased temperatures of our oceans are causing thermal expansion. This means that our oceans are slowly expanding. Scientists say that thermal expansion has driven about 75 percent of the rise in sea level (Spalding, 2002). These warm temperatures are also causing a rapid loss of glacial ice around the world. One might think, who cares if the oceans are expanding? What impact does this have on me? Well, this is actually having a large impact on human civilization. Expanding oceans are causing incidents such as sea level rise and flooding. These are huge problems especially for those individuals in third world countries who do not have money for proper protection from these problems. For example, last year the government of Tuvalu asked New Zealand to accept its entire population as environmental refugees. Most of this island lies almost at sea levels and huge storms are destroying its cities and populations (Spalding, 2002). Large storms are destroying such third world countries. Just imagine what adding 20 or 30 cm to a high storm surge can do to a city on a low-lying coastal area.

The increasing sea level is creating more dangerous storms. However the direct effects of global warming are creating more severe weather, as well. Scientists have discovered that increasing temperatures and the release of such greenhouse gases as carbon dioxide are creating more massive and destructive storms (Begley, Glick, 1992). They say that global warming increases air and ocean temperatures and may strengthen the forces that cause storms. The forces that cause storms include water vapor, rising, cooling, and releasing heat into the air. When all of these factors are increased, the chances of a more severe storm are increased, as well. Atmospheric physicist Michael Oppenheimer of the Environmental Defense Fund said, "More moisture would feed energy into the storms, and they would increase in size and severity." (Begley, Glick, 1992). Perhaps this is the reason why we have seen both