Climate Change
There have been around five major Ice Ages in the Earth's past. The last one, the Quaternary glaciation (also known as the Pleistocene glaciation) started 2.58 million years ago.
The Little Ice Age (LIA)
No one seems to agree on the exact timing of the most recent cooling which appeared after the Medieval Warm Period - Medieval Climate Optimum - which was actually not so optimum, not what we would call warm weather today. What is interesting is the lack of information in history books on the influence climate change, and subsequently the potato, had in the rise of western civilization as a dominating world power.
Put altogether the Little Ice Age would have occurred between 1350 and 1850, with several particularly cold periods every hundred or so years after intervals of warmer weather. Farmers did not know how to adapt their crops from the warmer climate conditions which caused starvation. The bubonic plague would not have been so devastating - killing around half the population in Europe in the mid-14th century - had people been sufficiently nourished.
Sometimes the population went hungry out of plain stupidity. Until potatoes were promoted by King Louis XIV the French were dying because they wouldn't eat them, it wasn’t in their culture. Too little, too late. The French fially did adopt the tuberous as nourishment but wearing a potato flower in one's lapel or encouraging the potatoes to be cooked in fine restaurants wasn't enough to stop the La Révolution.
The tuber was first introduced to Europe by explorers back from Peru in the 16th century through the British Isles and Spain. It was was sent to feed troops in Spain's northern empire and the peasants planted it locally. The tuber resisted bad weather and was less visible than grain that would end in the hands of enemy soldiers. It was the only alternative crop to stave starvation until the potato blight hit many European countries, particularly Irland where it was the only crop.
“By feeding rapidly growing populations, the potato permitted a handful of European nations to assert dominion over most of the world...” (William H. McNeill).
