The Story of the Japanese 01680 [Interlude] The Arrival of the Little Ice Age

The causes of the arrival of Japan's Sengoku period are often cited as:
・The collapse of the order centered on the Muromachi Shogunate due to the Onin War
・The split of the Shogun's family due to the Meio Coup, which heightened the trend of gekokujo (the low overcoming the high)
However, in recent years, the theory citing the "arrival of the Little Ice Age" as a cause has also been gaining attention.
From the 15th to the 19th century, solar activity weakened, and the period from the 15th to the 16th century in particular is called the "Spörer Minimum," during which the Earth's temperature is said to have dropped by an average of about 0.5 to 1 degree Celsius. In addition, the submarine volcano Kuwae in the South Pacific erupted, and the ash ejected into the atmosphere caused a decrease in solar radiation. While this is not a major change compared to the full-scale ice ages of over 10,000 years ago, it is called the "Little Ice Age."
Although it was only a drop of about 0.5 to 1 degree, this temperature decrease is thought to have caused significant damage to agricultural crops and triggered nationwide famines. It is argued that the struggle over this limited pie led to the arrival of the Sengoku period, which lasted for over 100 years. While this theory is not yet widely accepted in academia, it is certainly a theory worthy of attention.
On the other hand, such theories seem to downplay the dynamism of individual history, such as the split between the Shogun's family and the Kanrei families.
"It is not individual politicians who move history. Larger factors like the trends of the masses and climate change are what change history."
This argument is certainly plausible, but history can change in any number of ways due to accidental factors, and it does not necessarily contain universal principles.
In recent years, many books such as "Understand X in 3 Hours" or "Learn X in Your Spare Time" have been published, and so-called "fast liberal arts" are in vogue. As I have mentioned before, the split between the Shiba and Hatakeyama families occurred due to extremely complex causes and followed an extremely complex course, so it cannot be learned through "fast liberal arts." The emergence of a new theory like the "arrival of the Little Ice Age," which can be understood in one minute and seems to take a broad perspective while ignoring details, is welcomed with open arms.
As stated in the preface, this manuscript is a project that aims for a general history focusing on the personalities of individuals. It also goes directly against "fast liberal arts" and emphasizes thorough detail. Therefore, I would like to summarize that the cause of the arrival of the Sengoku period was the Kyotoku Incident and the Onin War, and that it occurred accidentally due to a combination of the interests and personalities of the many people involved in these two events. I believe that complex things should not be simplified unnecessarily, but should be understood in their complexity.