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The Subatlantic is the current climatic phase of the Holocene. It started at about 2,500 years BP and is still ongoing. Its average temperatures were slightly lower than during the preceding Subboreal and Atlantic. During its course the temperature underwent several oscillations which had a strong influence on fauna and flora and thus indirectly on the evolution of human civilisations. With intensifying industrialisation, human society started to stress the natural climatic cycles with increased greenhouse gas emissions.〔http://www.acs.org/content/acs/en/climatescience/greenhousegases/industrialrevolution.html〕〔http://www.epa.gov/climatechange/ghgemissions/gases/co2.html〕〔http://www.columbia.edu/~vjd1/greenhouse.htm〕 == History and stratigraphy == The term ''subatlantic'' was first introduced in 1889 by Rutger Sernander〔Sernander, R. (1889). Om växtlämningar i Skandinaviens marina bildningar. Bot. Not. 1889, p. 190-199, Lund.〕 to differentiate it from Axel Blytt's ''atlantic''.〔Blytt, A. (1876a). Immigration of the Norvegian Flora. Alb. Cammermeyer, Christiania (Oslo), p. 89.〕 It follows upon the previous ''subboreal''. According to Franz Firbas (1949) and Litt ''et al.'' (2001) it consists of the pollen zones IX and X.〔Firbas, F. (1949). Spät- und nacheiszeitliche Klimageschichte Mittel-Europas nördlich der Alpen. I. Allgemeine Waldgeschichte, p. 480, Jena.〕〔Litt, T. ''et al.'' (2001). Correlation and synchronisation of Lateglacial continental sequences in northern central Europe based on annually laminated lacustrine sediments. Quaternary Science Reviews, 20, p. 1233–1249.〕 This corresponds in the scheme of Fritz Theodor Overbeck to the pollen zones XI and XII.〔Overbeck, F. (1950a). Die Moore Niedersachsens. 2. Aufl. Veröff. d. niedersächs. Amtes f. Landesplanung u. Statistik, Reihe A I, Abt. Bremen-Horn, vol. 3, 4.〕 In climate stratigraphy the subatlantic is usually subdivided into an older subatlantic and a younger subatlantic. The older subatlantic corresponds to pollen zone IX (or XI) characterized in central and northern Europe by beech or oak-beech forests, the younger subatlantic to pollen zone X (or XII). In eastern Germany Dietrich Franke subdivides the subatlantic into four stages (from young to old):〔Franke, D. (2010). Regionale Geologie von Ostdeutschland – Ein Wörterbuch.〕 * youngest subatlantic: 1800 until present: modern history * younger subatlantic: 1250 until 1800: High Middle Ages, Late Middle Ages, Early Modern Period * middle subatlantic: 500 until 1250: migration period and Slavic migrations * older subatlantic: 500 BC until 500 AD: pre-roman iron age, ancient Rome and start of migration period. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Subatlantic」の詳細全文を読む スポンサード リンク
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