Global Climate Changes

          The Medieval Global Temperature Optimum, which occurred from approximately 900-1300 AD, was a time period in European and North American climatic history that saw temperatures comparable to, or even exceeding, those of the late 20^th century. This period was, however, marked by cooler and warmer periods as well. Due to this Medieval Warm Period, agriculture was at a prime. Records show that harvests were remarkably high in Europe, as “agriculture was possible at higher latitudes” (Mann). For example, grapes in England were grown hundreds of kilometers north of their current limit of growth, as were fig and olive trees in Italy and parts of Germany, respectively. Another outgrowth of this climatic period was glacial movement. Glaciers receded rather rapidly during this period, and advanced in later periods. Severe winters were also less prevalent, as indicated by “ A host of historical documentary proxy information such as records of frost dates, freezing of water bodies, duration of snowcover, and phenological evidence (e.g., the dates of flowering of plants)” (Mann).

            The Little Ice Age, which occurred between the 16^th and mid-19^th centuries, marked the end of the Medieval Global Temperature Optimum.  There were three notable intervals of temperature drops in the Northern Hemisphere during this period: one occurring around 1650, another in 1770, and the final one around 1850. Each of these colder periods was followed by periods of mild warming. These fluctuations in temperature have been “associated with a particularly dramatic series of mountain glacier advances and retreats” (Mann). These dramatic temperature oscillations also affected human populations. Most notably in Greenland, Norse settlers arrived around AD 1000 and had thriving cattle and sheep farms. These successful farming settlements lasted until about AD 1400, at which time they were lost to the advancing fronts of mountain glaciers. Crop yields also declined drastically during this time period, as the cooler temperatures did not support agriculture. Rates of child mortality, famine, and disease were also several outgrowths of the Little Ice Age, particularly in Europe.  

Works Cited

Mann, M. E. (2002). Little Ice Age. In Encyclopedia of Global Environmental Change (Vol. 1, pp. 504-509). Chichester, England: John Wiley & Sons, Ltd.

Mann, M. E. (2002). Medieval Climatic Optimum. In Encyclopedia of Global Environmental Change (Vol. 1, pp. 514-516). Chichester, England: John Wiley & Sons, Ltd.