Global Climate Change

           The Medieval Global Temperature Optimum, also know as the Medieval Warm Period, was a period of time from approximately the 9th to 13th centuries in which Europe and neighboring North Atlantic regions experienced temperatures comparable to, or even exceeding those of the late 20th century. With these higher temperatures, various plants and crops were grown and harvested in regions that are well north of their limits today. This is exemplified by the growth of grapes in northern regions of England that are not able to produce such crops today. Subtropical growth, such as fig and olive trees, was seen in regions of Italy and Germany that are well north of their current growth limits. Another outgrowth of this increase in temperature was the settling of Greenland and Iceland by Norse colonizers, who used these lands as places of agricultural growth and trade with mainland Europe due to the favorable climate conditions. Though theories differ slightly, it is strongly believed by some academics that this warm period did not impact the entire globe, and many believe that Europe and other regions in the North Atlantic were the primary areas in which this temperature increase took place.
          On the opposite end of the spectrum, from approximately 1300 to approximately 1870, much of Europe and North America experienced a period of lower temperatures and harsher winters known as the Little Ice Age. The exact cause of this dip in temperatures is unclear, but some academics have proposed that it stemmed from lower sunspot activity. This would result in less energy output from the sun that could warm the Earth. With less favorable climate conditions for subsistence farming, this era saw a great expansion of European trade, colonialism, and the rise of sea-born imperial powers, in particular that of Great Britain. With greater trade and expansion of global markets, there came a rise in specialization for international markets. The advances in technology that accompanied the later part of this era eventually culminate in coal and other fossil fuels becoming the main sources of power for industrial activity.
          These two counter-balancing periods of time impacted agriculture and trade in extremely different ways. Both drove trade to new heights and created stronger connections between the nations of Europe. It also epitomizes the idea that every time the pendulum of the climate swings one way, it will eventually swing that momentum back in the opposite direction.

For more information on these two eras, check out the links below:

http://www.eh-resources.org/timeline/timeline_lia.html

http://www.meteo.psu.edu/holocene/public_html/shared/articles/medclimopt.pdf

http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html