Medieval Warm Period

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The Medieval Warm Period idea was discovered by an English Climatologist known as Hurbert H. Lamb for the first time in 1965. He also founded the (CRU) UK Climate Research Unit where he estimated that the High Middle Ages temperatures were 1-2 degrees above the normal (Bianchi 2009, p.87). This period impacted most part of the North Atlantic and the regions surrounding it. The Little Ice Age period followed after the occurrence of High Middle Ages Period. During earlier Medieval Period, Europe experienced the mild climate conditions where agriculture was practiced in the higher latitudes (Scott 2004, p. 21). The medieval Warm Period could be regional other than global but some traces shows that the period existence in other parts of world (Bradley 2003, p. 13). In attempt to provide evidence for the occurrence of medieval warm climate as a global element, the Holocene, interglacial and the bond argued on the basis of ratio of iron-stained present in ice –rafted debris in North Atlantic (Bradley 2003, p.18). The objective was to reconstruct Holocene temperature fluctuation but the problem encountered was that the yield temperature was less than one degree percent (Scott 2004, p.30). The optimum temperature needed for the reconstruction could have been 0.5 degrees Celsius. Some of the records that tried to explain the existence of medieval warm period include the mountain glaciations record, the tree ring records, the corals and the remains of flora and fauna found on the sediments in lakes and bogs. Some of the papers that supports that the High Middle Ages could be global include the tree-ring reconstruction in the Southern Hemisphere. The records shows that above average temperatures were received in the New Zealand during the summer temperatures. The period was also experienced in the pacific basin where sea level rose reaching a maximum that exceeded the normal sea level. In Asia, evidence of medieval warm Period was characterized by the cultivation of citrus fruits which was never as far as to the north. The extreme warmth resulted to the existence of some insects such as the Heterogaster urticae beetle that was detected during the Roman Optimum (Bradley 2003, p.22). A case study in the northern part of the United States on the icy crystal known as Ikaite by geochemist Zunli Lu of Syracuse shows evidence of existence of Medieval Warm Climate. The case was 10,000 miles south of northern Europe (Mann 2003, p.85). The mineral forms in cold waters and constitutes water and calcium carbonate. The crystal could be found in Green land and off the coast of Antarctic Peninsula. The two climates were important because temperature variation resulted into the formation of the Ikaite. The hydrated water from the bottom of the ocean holds the crystal structures together hence during cooling. the ice sheets would expand as the bottom ocean water accumulates heavy oxygen isotopes (Goose 2006, p.223). Melting of glaciers causes mixture of the bottom water with the enriched light oxygen fresh water. When the ratio of oxygen isotope in calcium carbonate and that o hydrated water was taken, a correction of oxygen was determined between rises and fall. A conclusion in the Antarctic Peninsula was that the crystal Ikaite could build oscillations around the globe especially during the High Middle Ages (Peterson 2005, p.116). The Mediaeval Warm Period in South China The medieval warm per