Great Tenmei Famine
The Great Tenmei Famine, which struck Japan in the 1780s, was one of the deadliest famines of the Edo period. Cold summers, crop failures, and the effects of volcanic eruptions combined to cause widespread starvation, especially in the northeast, and the crisis exposed weaknesses in the Tokugawa shogunate's economic and political order. Its name comes from the Tenmei era, which ran from 1781 to 1789.
By the late eighteenth century, Japan's population had grown to roughly thirty million and had remained relatively stable for decades. The domain governments of the north, such as Tsugaru and Morioka, depended heavily on rice, a crop poorly suited to the region's short, cool growing season. Domains often encouraged rice farming for tax purposes and sold surplus stock to markets in Osaka and Edo, which left less in reserve for hard years. Climate was already unfavorable, as the period belonged to a cooler phase sometimes linked to the end of the Little Ice Age's harsher stretches.
Trouble began around 1782, when poor harvests started to appear. The crisis deepened in 1783, when the eruption of Mount Asama in central Honshu devastated nearby villages with pyroclastic flows and a massive debris flow. In the same year, the Laki fissure eruption in Iceland released huge quantities of sulfur gases. Historians generally agree that volcanic aerosols from these eruptions cooled the Northern Hemisphere, though how much each contributed to Japan's cold summers is still debated. Rains, chill, and crop disease left harvests in the northeast failing badly in 1783, and conditions remained grim for several years.
The human toll was severe. Accounts from northern domains describe people eating straw, grass, and even animals normally left alone, and there are reports of desperate migration toward towns. Epidemics followed in the weakened population. Death estimates vary widely, and many figures come from local records of uneven reliability, but the north suffered heavy losses and some areas lost a significant fraction of their people. Hoarding and speculation by rice merchants worsened the shortages, and prices soared.
Unrest followed. Peasant uprisings and urban riots, including major rice riots in Edo in 1787, shook the authorities. Tanuma Okitsugu, the senior official associated with commercially minded policies, fell from power in 1786. His successor, Matsudaira Sadanobu, launched the Kansei Reforms, which stressed frugality, grain storage, and a return of people to farming. The famine is remembered as a turning point that deepened doubts about shogunal governance, a pressure that would continue to build in the following century.