Historian Rodney Stark writes that “beginning sometime in the eighth century, the earth began to heat up, producing what now is known as the Medieval Warm Period, which lasted from about 800 to about 1250.”
One of the beneficial effects of the warming period was the fact that the growing season was lengthened all across northern Europe, thus making it possible to farm as far north as Greenland. In addition, the Arctic ice pack receded, which made it safer to sail in the North Atlantic.
After the warming period, there came in the early fourteenth century a Little Ice Age that ushered in an era of very cold winters and short summers that lasted until about 1850.
(Quote from Rodney Stark, How the West Won: The Neglected Story of the Triumph of Modernity, ISI Books, Wilmington, Delaware, 2014, p. 144.)
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