The second book on Climate Change is "Global Crisis: War, Climate Change; Catastrophe in the Seventeenth Century," by Geoffrey Parker, which tries to show a "fatal synergy" between climatological and political factors that produced turmoil from Europe to China in the period called "the Little Ice Age" (LIA) between the 1640s and 1690s. Unusual weather, protracted enough to qualify as a change in climate, correlated strongly with political upheavals as to constitute causation for the author.
Whatever caused the LIA — decreased sunspot activity and increased seismic activity were important factors — it caused, among other horrific things, "stunting" that, Parker says, "reduced the average height of those born in 1675, the 'year without a summer,' or during the years of cold and famine in the early 1690s, to only 63 inches: the lowest ever recorded." Such temperature declines "decreases the number of days on which crops ripen by 10%, doubles the risk of a single harvest failure, and increases the risk of a double failure six fold." For those farming at least 1,000 feet above sea level this temperature decline "increases the chance of two consecutive failures a hundredfold."
His conclusion: It is not surprising that more wars took place during the 17th-century crisis "than in any other era before the Second World War."
Correlation and causation are difficult concepts for most and probably should be avoided. But the fragility of the period--and the suddenness of the change--is provocative.
Whatever caused the LIA — decreased sunspot activity and increased seismic activity were important factors — it caused, among other horrific things, "stunting" that, Parker says, "reduced the average height of those born in 1675, the 'year without a summer,' or during the years of cold and famine in the early 1690s, to only 63 inches: the lowest ever recorded." Such temperature declines "decreases the number of days on which crops ripen by 10%, doubles the risk of a single harvest failure, and increases the risk of a double failure six fold." For those farming at least 1,000 feet above sea level this temperature decline "increases the chance of two consecutive failures a hundredfold."
His conclusion: It is not surprising that more wars took place during the 17th-century crisis "than in any other era before the Second World War."
Correlation and causation are difficult concepts for most and probably should be avoided. But the fragility of the period--and the suddenness of the change--is provocative.
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