How weather has shaped human history
Chinese scientist Shen Kuo was the first person to study climate. In his 1088 “Dream Pool Essays,” he ponders climate change after finding petrified bamboo in a habitat that wouldn't support such growth in his lifetime. Inventions and technological advances have allowed people to track and even control the weather. Around 1602, Galileo was the first to conceptualize a thermometer that could quantify temperature, allowing people to track changes in heat. The air conditioner made its first appearance in 1902; and in 1974 the Senate Committee on Foreign Relations held a classified briefing on the results of Operation Popeye, a five-year cloud-seeding experiment designed to lengthen Vietnam's monsoon season, destabilize enemy forces there, and allow the U.S. to win the war.
But far more often than humanity seeks to control the weather, the weather does the controlling.
While weather refers to short-term atmospheric conditions (think of a forecast for how sunny and warm it will be next week), climate refers to long-term changes in overall weather trends over time (decades or hundreds of years). The two are impacted by each other. Climate change affects the severity and frequency of weather events, and the costs of extreme weather events rise as the effects of climate change become more apparent. With increased technology allowing for the tracking of weather trends over time and the anticipation and identification of potential weather hazards, people have been able to avert and prepare for some of nature's wildest expressions.
But even in our modern era, some singular weather events have shaped human history. Sometimes these events are tied to climate change, other times they represent anomalies that changed the course of a war, affected the entire future of air travel, or launched eras of famine, disease, or forced migration. In this gallery, Stacker examines 30 ways weather has shaped human history, drawing on historical documents, newspaper articles, first-person accounts, and documented weather events. Keep reading to find out what event kicked off the Salem Witch Trials, a new clue in the JFK assassination, and how a heavy storm thwarted the end of the Iran hostage crisis in 1980.
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Climate change drove people out of Africa
There is no greater decider of human history than climate change, due to its long-term effect on weather conditions. The first and only example in this gallery of sustained climate change is here: it initiated the dispersal of people from Africa into other parts of the world.
Using modern-day computer modeling, scientists have discovered that humanity's earliest push out of Africa and into other reaches of the planet was most likely due to changing long-term weather patterns. In a September 2016 report in Nature, authors Axel Timmermann and Tobias Friedrich explore how strengthened monsoonal climates and wet conditions throughout the Arabian and Sinai peninsulas created clear migration paths laden with natural resources that opened and closed at different points in history—and that line up perfectly with evidence of human dispersal. Other migration patterns, such as those into north Asia, similarly line up with decreasing amounts of glaciers roughly 20,000 years ago.
541: Drought leads to first recorded bubonic plague
The first recorded bubonic plague epidemic arrived in the mid-sixth century and resulted in an estimated 25 million deaths (50 million, when you include its two centuries of recurrence), accounting for roughly half of all people living at the time in the Roman Empire and toppling balances of power across the globe.
Scientists point to a period of extreme droughts and colder temperatures in Africa during the 530s as the bubonic plague's cause. The lack of rain destroyed crops, which in turn depleted the population of small rodents that fed on those plants. The reduced number of these small rodents affected animals higher up the food chain, and populations of larger animals took longer than the vegetation to spring back when high levels of rain ended the drought; this lack of predators led small rodents to then populate in high numbers.
The influx of rodents infested East Africa and inevitably found their way to merchant ships bound for Europe and elsewhere. Many rats, gerbils, and mice also had fleas, which can carry a bacterium called Yersinia pestis. When rodent flea hosts died, the tiny bugs hopped to human hosts, infecting millions. Today, the plague still exists—but it's easy to treat with antibiotics.
900: Drought spells the end for Mayan civilization
During its peak around 800 AD, the Mayan civilization was responsible for awe-inspiring stone temples, almost four dozen cities, highly advanced astronomical observatories, and advances in mathematics and calendar-keeping that were far ahead of its time. Mayans also practiced slash-and-burn agriculture, which involves clear-cutting forest to grow land, then burning the vegetation that remains and moving onto a new plot. This method led to extreme deforestation in the Yucatan peninsula, a region that depended on root systems to maintain water tables after rainfall, its chief water source.
In a study published in Science in 2018, researchers found that, over 200 years, rainfall in the Yucatan peninsula dropped by as much as 70%. The extreme drought would have devastated any agriculture, turned dirt to desert, and made it impossible to survive if people stayed in their cities. The drought, combined with warfare, civil unrest, and other conflicts, spelled the end of the Mayan civilization. The Mayans themselves left behind a clue of how dire things had become. Among the ruins that thousands of tourists flock to each year are many carved stones in the shape of “Chaac,” the rain god of the Mayan culture.
1274: Kublai Khan and the Kamikaze
The weather thwarted Mongol fleets attempting to attack Japan in 1274 and 1281.
Genghis Khan's grandson Kublai Khan led both conquests, each of which was comprised of more than 4,000 ships with an army of 140,000 men, representing the largest-scale attempt of a naval invasion at that time (usurped only by the D-Day invasion in Normandy in 1944). Each attempt to overtake Japan failed epically because of typhoons, which the Japanese called “kamikaze,” or “divine wind.”
One of the ships from the 13th-century invasions was discovered in 2015 at the bottom of the ocean off the southern coast of Japan, according to a report from The Telegraph.
1315: Extreme weather spawns the Great Famine of 1315-1317
Harsh winters, unseasonably cold summers, and heavy rains blanketed Europe between 1315 and 1317, decimating agriculture and spreading disease that was exacerbated by malnutrition from reduced access to fresh food. The Great Famine was marked by an extremely wet spring and summer that destroyed crops, prevented grain from ripening, and caused the price of salt—the only way to cure meat at the time—to skyrocket as brine could not properly evaporate. Bread became a luxury only afforded by the wealthy. Millions died in the years that followed from starvation, rampant disease, infanticide, and even cannibalism. Agriculture in the region wasn't righted for a full decade, and the famine had dire consequences on European society, government, and the church.
Some blame the abnormal weather patterns on a massive volcanic eruption at Mount Tarawera in New Zealand in 1315 that lasted for five years. Ash from the eruption would have wreaked havoc on temperature patterns around the globe.
1588: The wind flubs the Spanish Armada's attack on England
In 1588, King Philip of Spain sent the Spanish Armada to invade England. Dropping anchor for the night, the fleet discovered unmanned, burning English ships floating toward them in the pitch black. The wind proved favorable for the English, who sent the ships they'd torched directly toward the Spanish—many of whom cut their anchor lines to get away.
Later, while traveling into the North Sea, the English were low on gunpowder and took harbor along the English coast. Unable to sail into the wind, through the English ships and on to Spain, the Spanish fleet continued north around Scotland. But with low food and water rations and many injured and sick sailors, the Spanish fleet resorted to starvation rations before running head-on into a heavy storm. Typically, ships would drop anchor to wait out the storm; however, many of the Spanish ships were traveling now without their anchors. Twenty-six of them smashed into the rocky Irish coast, killing close to 6,000 Spanish sailors and sparing England.
1601: Volcanic eruption in Peru causes famine during Russia's “Time of Troubles”
Before its eruption, the Huaynaputina volcano was thought to be a low Peruvian ridge. The deceptive crater packed a serious punch, spewing more than 7 cubic miles of ash and lava and causing a famine in Russia from 1601 to 1603 during the country's “Time of Troubles.” 1601 became the coldest year in six centuries, and its effects on agriculture and health contributed to the deaths of 2 million people—a full one-third of the country's population.
1692: Mini ice age instigates the Salem Witch Trials
The famous Salem Witch Trials between 1692 and 1693 ultimately resulted in more than 200 people being accused of practicing witchcraft and 20 people being put to death. Causes for the hysteria have been attributed to everything from socioeconomic issues in Salem to cold weather, which does overlap with periods of witch hunts throughout history.
The little ice age theory, laid out in 2004 by a graduate student at Harvard, contends that people thought witches could control the weather (and therefore could destroy food accessibility). Indeed, lower temperatures throughout the U.S. and Europe during a 400-year “little ice age” between the 1500s and 1800s also correspond to an uptick in accusations of witchcraft. The coldest period of this miniature ice age came between 1680 and 1730 and would have caused extensive hardship. Several diaries and even church sermons from this time suggest the bad weather helped to inspire the allegations.
1776: Fog saves the American Revolution
By the summer of 1776, Britain had increased its troop strength on Staten Island to more than 30,000 in a battle against Gen. George Washington's 19,000-man army for control of New York City. Half of the revolutionaries remained in Manhattan while Washington moved the rest out to Brooklyn and Queens, where British soldiers began their attack on Aug. 27. Americans stealthily made their way across the East River to Manhattan, totally undetected by the British soldiers just a few hundred yards away because of a dense fog cover.
Historians widely agree that Washington would have surely been captured and hung as a traitor while his army was overrun had it not been for that fog. Instead, the American Revolution ended in victory for the new colonies and the Treaty of Paris, which officially made the United States an independent nation.
1789: The witch trials' “little ice age” also spurs the French Revolution
The same miniature ice age that contributed to accusations of witchcraft in Salem, Mass., and throughout Europe also contributed to rising discontent in France. Colder temperatures throughout Europe and the United States, along with a 1783 volcanic eruption in Iceland and a band of warm ocean water in the central Pacific Ocean, resulted in widespread crop failures and drought across Europe.
In France, people were already strapped by taxes, which had been raised to support the American Revolution against the British Empire. The economic downturn and ravaged agriculture came to a head in 1788, when very heavy rains and hailstorms destroyed that year's grain harvest and decimated crops. The upheaval led straight to the storming of the Bastille—Paris' armory and political prison that served as a symbol of the monarchy's corruption—in 1789.