Corals are mostly found near or at the shore of lakes and other large water bodies. This means that coral gives a cross section of the soil stratification layers which can be assumed to have been each as top layer at a certain period in history (Bruckner, 8).
Closely examining the coral, the different layers usually have different compositions. These compositions are the ones that help in depicting the climatic conditions that existed at the time of the layer being top layer of the soil (Paul, 3).
If one layer of the coral can be closely examined and compared to the composition of another, it is evident that the two layers have different compositions of both the flora and the fauna. This means that the layers depict different eras in climatic history (Bruckner, 10).
If a layer contains a lot of flora and the few fauna fossils have heavy skins or coatings, the layer depicts a climatic era when the area had a cool and wet climate. This can be deduced from the fact that in the contemporary climatic classifications, areas with cool and wet climatic conditions have organisms with the stated characteristics. If the flora and fauna compositions can’t be precisely determined, then scientific methods like carbon dating are used to find the compositions to the highest levels of proximity. The age of the coral layer is also estimated using carbon-14 dating which is effective in dating historical artifacts (Paul, 3).
The other factor that can be used to deduce the climatic conditions of the past from coral study is its composition. Composition of coral which is dependent on available fossils and climate at the time of formation may reveal that the temperatures in time of formation were either high of low. If one layer of coral is harder than the other, the harder layer depict a slow formation in which the temperatures during formation were much low as compared to soft coral where the rates of formation were fast and compression was not very high (Paul,5).
Still in composition of the coral, climate dictates the type of crop that flourishes in the area. This translates in a composition which is dependent on the climate in terms of both the flora and fauna. For example, considering a layer where the fauna fossils are more compared to the flora, it means that the climatic conditions at the time that the particular layer was at the top was a lowland climatic condition meaning either hot and wet or hot and dry. This is because a lot of animals are expected to live in areas where the temperatures are not very low as in cool and wet or very high as it is the case in hot and dry climatic conditions (Paul, 15).
Lastly, the coral layers may have sediments which are compacted and preserved within the layers. The preserved fossils may give information about the climatic conditions at the time of preservation. This means that the fossils may be analyzed to show the composition of the plant remains found or animal remains and the data obtained processed further using scientific methods to give a conclusive hypothesis on the climatic conditions at the time of coral formation. From these composition statistics and scientific analysis, climatic conditions can be directly deduced. This is the idea primarily employed in paleo-climatology and is extended to cover even the ring formation in plants. These rings have different compositions indicating different mineral availability, external factors affecting the tree and other physical effects including climate on the plant. With this piece of information, we can proceed to analyze the effectiveness of this method in reconstructing the climatic conditions from the provided evidence and contemporary scientific studies (Paul, 22).
Turning to the strengths and weaknesses of this proxy, several advantages can be directly deduced from this proxy. One advantage of this proxy is the reduced effort in reconstruction of climatic conditions that prevailed before record keep in climatic conditions began. This is made easy by the direct observation of the coral layers giving the very first insight of how many times the climate of a region has changed. The more the number of layers with different compositions, the many times the climate of the area has changed (Paul, 26).
The second advantage is the ease of coral composition determination by simple scientific experiments. This is closely related to the composition of the coral layers and the certain minerals or elements as they can be tested using scientific methods. The main element contained in coral is carbon which is mostly from the fossils. Fossils of different organisms have different carbon content thus by determining the carbon content in a certain fossil and comparing it to the carbon content of a similar organism, one can easily predict the climatic conditions of the area at the time of coral layer formation (Paul, 26).
The other advantage of this proxy is the ease in comparison between the data obtained from the fossils and the contemporary data from similar organism. By studying the contemporary organisms and where they live, it is possible to determine the climatic conditions of the past.
Moving to the disadvantages, several of them comes with this approach. The first disadvantage is reduced experimental proof due to lack of sufficient evidence to support the idea that no assumptions are made. Closely examining the proxy, very many assumptions are made making the data obtained to be only estimates without any other refining methods in pursuit for the most precise information (Paul, 29).
The other disadvantage is localization of coral only to specific zones of the earth’s crust. From geography, most of the coral rocks are localized to ocean or lakes shores where water can be said to have easy access to the rock formed. This makes this type of paleo-climatic proxy inappropriate to use in determination of past climatic conditions of zones far away from large water bodies (Paul, 30). Though boreholes can be used to stand in for the large water bodies, it does not have the same coral formation as the large water bodies (Fritz, 6). This makes the proxy misleading to the researchers for inland study. To counter this, the scientists opt to consider tree rings for inland paleo-climatology (UniSci, 18).
Moving on to scenario making use of such proxies, global warming can be explained using this knowledge. From the study of coral, boreholes and tree rings, it has been found that temperatures of the earth have been elevating as years progress. This makes the water level in the large water bodies to drop leading to formation of coral which shows characteristics of high temperature at the time of formation. The layers of the coral appear to be stratified according to temperature in formation. This makes this proxy very valid in explaining the global warming (UniSci., 12). From the tree rings proxy, the same scenario can be explained by determining the color of a tree ring under different temperatures. From scientific research, as temperatures become higher, the colors of rings become lighter. The tissues of the ring also become softer due to reduced compactness of the tissue grains of the tree. This is indicated by dark inner rings compared to outer rings in trees aging above a hundred years (Fritz, 14). Lastly on global warming, temperature elevation has been attributed to accumulation of carbon (IV) oxide in the lower atmosphere allowing penetration of solar radiation but preventing terrestrial radiation from escaping (UniSci., 13). The rise of carbon (IV) oxide content in the atmosphere can also be determined from analysis of coral composition. Coral layers have carbon as one of the major components thus analyzing the variation of its content has indicated gradual rise from the bottommost layer to the topmost layer. This indicates increase in carbon (IV) oxide in the atmosphere with time as predicted.
In conclusion, paleo-climatic proxies are very important in explaining some current issues which require analysis of past climatic conditions. They help in revealing the climatic conditions that prevailed long before record keeping and ease the reconstruction of climatic conditions, a scientific factor that posed a great challenge to the scientists. It also supports some historical factors at least providing some evidence for historical data.
UniSci. Borehole Temperatures Confirm Global Warming Pattern. Oxford University Press, 2004 Print
Paul P. Earth Observatory: Coral Layers Good Proxy for Atlantic Climate Cycles. Princeton Inc, 2009 Print.
Bruckner and Monica. Paleo-climatology: How Can We Infer Past Climates? Penguin Publishers, 2009 Print.
Fritz H. Tree Rings: Basics and Application of Dendrochronology. Dordrecht: 1988 Print.