What makes societies unravel? Historians usually point to politics, corruption, or inequality. But a new study suggests that climate effects that trigger extreme weather may also play an important role.
Researchers from the Université de Toulouse and CNRS, led by David Kaniewski, analyzed centuries of climate records, solar activity, volcanic eruptions, and grain prices, then compared them to Europe’s long record of uprisings. They ended up analyzing 140 rebellions between 1250 and 1860, finding good evidence that climate triggered some of Europe’s most impactful events.
The French Revolution
The French Revolution of 1789 is a strong contender for the “most impactful event in history.” It had a profound and lasting impact on global political thought and social structures. It gave birth to concepts fundamental in today’s democracy, including liberty, equality, and the rights of man. The Revolution overthrew autocratic rule, established the principles of popular sovereignty, and inspired movements for freedom and anti-colonialism worldwide.
What could climate possibly have to do with it?
France in the late eighteenth century was a kingdom on the edge. In theory, the monarchy was absolute but financially, it was bankrupt. Socially, the country had a rigid class system divided nobles, clergy, and commoners, where the commoners paid the most taxes while the rich collected. But things may have gone a different way had the Sun been in a different cycle.
Around 1770, Europe entered what scientists call the Dalton Minimum, a period of especially low solar activity. That dip coincided with bitterly cold winters that destroyed crops across northern Europe. France, still a heavily agricultural society, was particularly exposed.
In 1775, after years of poor harvests, the kingdom erupted in the Flour War — a wave of bread riots. People attacked granaries, convinced merchants were hoarding grain. Things got even worse in 1783, when Iceland’s Laki volcano erupted. It spewed so much sulfur into the atmosphere that Europe’s skies dimmed. The eruption made the summer scorching hot, bringing massive hailstorms that affected crops. Then, the following winters were punishingly cold. This cycle of extremes ruined harvests for several years. By 1788, France’s agricultural production decreased by over 20%.
The final blow came that winter, the coldest in nearly a century. Rivers froze solid and food shortages became famine. Malnutrition became common. By 1789, France’s people were not only angry at their rulers but also desperate to survive; the revolution was unavoidable.
This doesn’t mean that climate caused the French Revolution, but it seems to have acted as one of the catalysts. France’s monarchy was already weak and its tax system was very unfair. But climate shocks turned grievance into action.
But this is just one data point.
Climate Revolutions
France may have offered the most dramatic case, but the study shows that the entire European continent was repeatedly rattled by climate-driven unrest. Between 1570 and 1860, researchers identified numerous uprisings clustered around the coldest, driest phases of a cold period called the “Little Ice Age”.
In northern Italy, the 1590s brought one of the deadliest food crises of the era. Several consecutive years of brutal weather crippled harvests. Just like in France, Grain shortages turned into famine. Historian Guido Alfani has shown that demographic pressure only worsened the disaster, pushing communities into revolt.
The Dalton Minimum (1789–1852) brought brutal winters and recurring droughts in Russia as well. Peasant unrest grew, sometimes exploding into rebellion, though this was nowhere near as consequential as in France. England is a special case: while it did suffer climate-driven crises, earlier political changes (1640s Civil War, 1688 “Glorious Revolution”) gave it institutions better able to absorb shocks, which may explain why it didn’t have a French-style revolution later.
Even the celebrated Revolutions of 1848, usually explained as liberal and nationalist uprisings, carried a climatic backdrop. The years leading up to 1848 saw bitter winters and harvest failures across Europe. A significant European potato failure in 1845-1847 contributed to mass starvation, poverty, and unrest, and bread prices soared, fanning discontent from Paris to Vienna and Bucharest to Berlin. Political demands for freedom and representation were sharpened by the hunger in the streets.
Why This Matters
Kaniewski and colleagues emphasize that they’re not saying “cold weather caused revolutions.” Instead, they argue that climate acted as a catalyst, a force that amplified existing vulnerabilities and made crises more likely. Intense climatic episodes “triggered a cascade of environmental and human events that interacted”, the researchers conclude.
The lesson is uncomfortably clear. When harvests fail and the situation is not so good to begin with, hunger combines with anger to create revolt. The peasants who stormed the Bastille weren’t reading solar charts or volcanic records; they were demanding bread. Their desperation was influenced by climate, but it manifested very powerfully, very locally. England, with its well-established and supportive institutions, managed to weather the storm. In more fragile societies, the effects were devastating.
Today, we’re also in a climate crisis. The weather is getting hotter year after year, triggering extreme events and affecting our already overpressured agricultural systems. The details differ, but the dynamic is familiar: environmental shocks collide with fragile politics and widening inequality. If anything, the effects we feel today are much stronger than the ones in the Little Ice Age. If this study has a warning, it’s that climate change doesn’t can easily alter fragile societies. Are we really that much better prepared than 18th century France?
The study was published in the journal Global and Planetary Change.
