Scientists nowadays, are researching widely and are looking for any little information that might assist them in trying to link Global Warming and the El Niño phenomenon. They have not been successful at this though. They are positively sure that the two are related but their theory, at the moment, is only speculation. Lately though, in the past few years, scientists have been finding increased amounts of evidence to support their claim. The evidence is quite intriguing and interesting to read, but to understand the scientists’ theories, one must first understand exactly what El Niño, La Niña and Global Warming are. Also to form a view on the matter one must also be able to identify and analyse the discoveries made.
Global Warming is the increase in the average temperature of the Earth. At present the Earth is warming very quickly. This warming is mainly due to human activities, such as the burning of fossil fuels such as coals. These release Carbon Dioxide (CO2) into the atmosphere. This gas and other greenhouse gases such as CFCs (chlorofluorocarbons) and Methane accumulate in the atmosphere. These greenhouse gases allow the Sun’s light and heat to pass through them and enter the Earth’s atmosphere but do only allow the light to leave. They do not allow the heat to pass back through them and the heat is trapped in the Earth’s atmosphere causing Global Warming. This process is known as the greenhouse effect. Scientists are predicting that the Earth’s average temperature will increasing drastically (between 1.4 and 5.8 degrees Celsius or 2.5 and 10.4 degrees Fahrenheit) over the next 100 years. It is true that average temperatures are rising. Records show that the 1990s has been the warmest decade ever. Global Warming is one of the few theories that scientist universally agree on. They all believe that Global Warming is on its way. It is believed that this rapid warming of the Earth will have diverse effects on countries and places all over the world. For instance, it is thought that weather will be more intense. Hurricanes will come with stronger winds, rainy seasons will be extended and when droughts come they will be worse and for longer periods. This extra rainfall can be helpful for agricultural usages but can also be the cause of flooding. The hurricanes will be powerful are most likely to cause severe damage to structures and people’s lives. Drought will cause agricultural yields to decrease significantly and that will be a major blow to most countries’ economies. One of the most fearing effects that can and might be caused by Global Warming though is the melting of polar ice caps. This act would cause the sea level to rise by 9 – 100 cm (centimetres) or 4 – 40 in. (inches). This will threaten all low-lying countries. For example, it is said that all of the Lesser Antilles and the states on the eastern seaboard of the U.S.A. will be covered with water and thus becoming underwater lands. Humans will be forced to evacuate and flee to other lands. This will also greatly affect the lives of animals that cannot easily adapt to changes in their environment. These animals can potentially become extinct. The sea and ocean waters may be come so warm that certain species of fish and marine organisms can no longer live there. Global Warming definitely has a negative impact on the Earth.
El Niño originally was the name fishermen in the 1500s gave to the phenomenon that causes the water in the Pacific Ocean to warm every year around Christmas and their catching of fishes to dwindle. At that time they did not really know what was causing this. Normally, wind coming from inland would blow out to sea. This wind would take with it out to sea the surface water of the Eastern Pacific Ocean. To replace the water taken out to sea, water from the ocean floor would rise and take its place. Coming with the water form the ocean floor would be nutrients. This process is called upwelling. Fish and marine life lived on upwelled nutrients. During an El Niño the winds were reversed. This stopped upwelling and the fish and marine life could not get food and they died. Also as the winds came inland from the sea, they brought with them lots of rain. During an El Niño the water becomes warm because as the wind blows inland it brings with it warm water from out at sea. An El Niño causes different effects in the eastern and western hemispheres. For instance, it brings rain to places in the eastern hemisphere and causes drought in the western hemisphere.
La Niña is the Spanish for the little girl. It is the reverse or antithesis of the El Niño. During La Niña the Pacific Ocean along the coasts of Ecuador and Peru becomes colder. Normally, the winds going out to sea take with them warm water and cool water returns to the coastal regions of Ecuador and Peru. During La Niña these winds strengthen. A lot more warm water is taken out to sea and so a lot more cool water is brought back to the shores. As a result of the cool water, La Niña causes drought and periods with small amounts of rain in the eastern hemisphere and in the western hemisphere brings a lot of rain. The La Niña is also sometimes called El Viejo (The Old Man) or anti-El Niño.
Normal Conditions El Niño conditions
La Niña Conditions
Scientists have said that they believe that Global Warming has an effect on the El Niño and La Niña. El Niños and La Niñas vary in strength and intensity and so scientists feel that it is likely to be so because the El Niños are sensitive to their environment, meaning that Global Warming has an impact on them.
Although this is true, scientists still cannot prove that Global Warming has an impact on El Niño/ La Niña. A climate scientist named Kevin Trenberth thinks that the El Niño acts as a release valve for the heat produced in Global Warming. Although this theory is quite practical he cannot be sure, as technology is not as yet that advanced. So for now the impact of Global Warming on the El Niño remains speculation.
Bibliography
- www.encarta.com
- http://gcmd.gsfc.nasa.gov/Resources/Learning/elnino.html
- http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html
- http://www.msc-smc.ec.gc.ca/education/elnino/what_is/index_e.cfm
- http://www.changingclimate.org/content/articles/article/data/section_3/article_89/part_458
