Little Ice Age

• 1. Introduction

  ›

  The Little Ice Age left a Swedish army marching across a frozen sea. In early 1658, soldiers walked over the Great Belt strait to attack Copenhagen from the west, an act made possible only because the winters had grown severe enough to freeze what was normally open water. That single moment captures the strangeness of the era: a climatic shift that reshaped warfare, agriculture, art, and empire across centuries. The term itself was introduced into scientific literature by François E. Matthes in 1939, but the conditions it names had been transforming human life since at least the 13th century. How cold did it really get? Was it a true ice age? What caused it? And who suffered, who adapted, and who, against all odds, thrived?

• 2. Defining a Contested Chill

  ›

  The Little Ice Age was not a true ice age of global extent, and its boundaries have never been agreed upon. The period has conventionally been defined as extending from the 16th to the 19th centuries, but some experts prefer a span from about 1300 to about 1850. NASA's Earth Observatory identified three particularly cold intervals: one beginning around 1650, another around 1770, and a last around 1850, each separated by brief periods of slight warming.

  The Intergovernmental Panel on Climate Change Third Assessment Report, issued in 2001, concluded that the affected areas and timing suggested largely independent regional climate changes rather than a single, synchronized global freeze. Viewed across the Northern Hemisphere as a whole, the cooling was modest, less than 1 degree Celsius relative to late twentieth-century levels. The IPCC's Sixth Assessment Report described the coldest stretch as a multi-centennial period beginning around the 15th century, with global mean surface temperatures averaging roughly -0.03 degrees Celsius between 1450 and 1850 relative to the 1850-1900 baseline.

  The starting date is particularly contested. Pack ice in the North Atlantic began advancing southward in the 13th century, and anecdotal evidence points to expanding glaciers almost worldwide around that time. Radiocarbon dating of roughly 150 dead plant samples collected from beneath ice caps on Baffin Island and Iceland, conducted by Miller et al. in 2012, placed the abrupt onset of cold summers and ice growth between 1275 and 1300, followed by a substantial intensification from 1430 to 1455. One possible trigger was the massive eruption of the Samalas volcano in 1257, which may have initiated a volcanic winter severe enough to prevent climatic recovery.

• 3. Europe Transformed

  ›

  Farms and villages in the Swiss Alps were buried under advancing glaciers during the mid-17th century. That same cold locked canals and rivers across Great Britain and the Netherlands hard enough to support ice skating and winter festivals, and merchants adapted their boats with wooden runners so trade could continue during winters that often spanned five months. The first frost fair on the River Thames was held in 1608; the last was in 1814.

  A year-by-year reconstruction of winter temperatures in Central Europe, published in 2021 by historian Christian Pfister and climatologist Heinz Wanner, found that the 17th century was the coldest, with temperatures running about 1.2 degrees Celsius below the 1961-1990 average. The 15th century was almost entirely cold, and winters from 1565 to 1573 and again from 1587 to 1595 were particularly severe. Cold summers in the 1450s, seven of them in that decade alone, are thought to have been connected to the eruption of the tropical Kuwae volcano.

  Sea ice surrounding Iceland extended for miles in every direction and closed harbors to shipping. The population of Iceland fell by half, a drop that may have been compounded by skeletal fluorosis from the eruption of Laki in 1783. Greenland's Norse Viking settlements, cut off as the climate grew colder and stormier after 1250, watched their diet shift steadily away from farming: by around 1300, seal hunting provided over three quarters of their food, and the last document from those settlements dates from 1412.

  The climatologist Hubert Lamb, writing in 1995, noted that in many years snowfall was much heavier than recorded before or since. Lisbon experienced frequent snowstorms, and one 17th-century winter there produced eight snowstorms. Famines in France in 1693-94, Norway in 1695-96, and Sweden in 1696-97 each claimed roughly 10 percent of those countries' populations. In Estonia and Finland in 1696-97, losses were estimated at a fifth and a third of the national populations.

• 4. Scapegoats and Social Unrest

  ›

  Beginning in the 1380s, just as the Little Ice Age tightened its grip, European populations began linking magic to weather-making. The first systematic witch hunts started in the 1430s, and by the 1480s it was widely believed that witches should be held accountable for poor harvests, livestock epidemics, and late frosts. Scholars Oster (2004) and Behringer (1999) both argued that this resurgence of witchcraft prosecution was driven by climatic decline. The number of trials rose as temperatures dropped and fell when temperatures rose. Peaks of persecution overlapped with the hunger crises of 1570 and 1580, the latter lasting a decade. The trials targeted primarily poor women, many of them widows.

  Jewish communities across Western Europe faced different but equally violent scapegoating. During outbreaks of the Black Death in Western European cities in the 1300s, rumors spread that Jews were poisoning wells, and Jewish populations were murdered in attempts to stop the plague. Some fled to the Ottoman Empire, Italy, or the Holy Roman Empire, where they found greater toleration.

  In Germany, regulations were imposed on gambling and drinking that disproportionately affected the lower class, and women were forbidden from showing their knees. In Ireland, Catholics blamed the Reformation itself for the bad weather. The Annals of Loch Cé, in its entry for 1588, described a midsummer snowstorm with hailstones as large as wild apples and attributed it directly to a heretical Protestant bishop.

  Historian Wolfgang Behringer linked the most intense witch-hunting episodes directly to agricultural failures during the Little Ice Age, and the anthropologist Brian Fagan of the University of California at Santa Barbara documented the broader plight in a book covering European peasants from 1300 to 1850, including famines, bread riots, and the rise of despotic leaders brutalizing an increasingly desperate population. In the late 17th century, Alpine villagers survived on bread made from ground nutshells mixed with barley and oat flour.

• 5. Art and Ingenuity

  ›

  Pieter Bruegel the Elder painted all of his famous winter landscapes around 1565, including Hunters in the Snow. According to the art historian William Burroughs, winter scenes in European painting occurred almost entirely between 1565 and 1665, a period that aligned precisely with the climatic decline from 1550 onward. Burroughs hypothesized that the unusually harsh winter of 1565 inspired artists to depict highly original images, and that later mild winters interrupted the flow of such work. Hans Neuberger analyzed 12,000 paintings held in American and European museums and dated between 1400 and 1967; his 1970 study found that depictions of cloudiness and darkness peaked between 1600 and 1649.

  The violinmaker Antonio Stradivari produced his instruments during the Little Ice Age. The colder climate may have caused the wood used in his violins to be denser than wood from warmer periods, and this density may have contributed to the distinctive tone of his instruments.

  The science historian James Burke argued that the cold period spurred practical inventions as well: the widespread use of buttons and buttonholes, the knitting of custom-made undergarments, and the invention of the chimney to replace open fires in communal halls, which allowed houses with multiple rooms to separate masters from servants. The iceboat was also born during this era, as merchants fitted their Dutch-style boats with planks and runners to keep goods moving across frozen canals and waterways.

  Not every society buckled. The environmental historian Dagomar Degroot of Georgetown University, writing in The Frigid Golden Age, argued that the Little Ice Age transformed the environments around the Dutch Republic in ways that made them easier to exploit. Merchants profited from harvest failures elsewhere, military commanders used shifting wind patterns to their advantage, and inventors developed technologies suited to the cold. The 17th-century Dutch Golden Age, Degroot argued, owed much to the flexibility with which its people responded to the changing climate.

• 6. A World in Crisis

  ›

  Episodes of social instability across Europe tracked the cooling with a time lag of up to 15 years, and many developed into armed conflicts. The Thirty Years' War, which ran from 1618 to 1648, began as a conflict over succession to the Bohemian throne but escalated into a pan-European war that devastated much of Germany. When it ended, some regions of the Holy Roman Empire had seen their population drop by as much as 70 percent.

  In the Ming dynasty, rainfall in the Huabei region dropped by 11 to 47 percent from historical averages between 1632 and 1641. The Shaanbei region along the Yellow River experienced six major floods, devastating cities such as Yan'an. According to Coching Chu's 1972 study, the period from 1650 to 1700, spanning the end of the Ming dynasty and the start of the Qing, was one of the coldest in recorded Chinese history. From 1573 to 1620, famine caused by extreme snowfall in Manchuria depleted agriculture and devastated livestock. The Wanli Emperor still demanded the same tribute from the Jurchen people, and that anger fed the rebellion that led to the founding of the Later Jin dynasty in 1616. By 1644, Li Zicheng's forces had entered Beijing and overthrown the Ming.

  In the Ottoman Empire, a wave of extremely cold winters began in the 1590s, and the longest drought in the Middle East in six centuries struck at the same time. Settled peasants unable to move their lands rose in revolt, producing the Celali Rebellion of roughly 1596 to 1610, the longest-lasting internal challenge to Ottoman state power in six centuries of that empire's existence. In February 1621, the Bosphorus Strait in Istanbul froze over completely. The Ottoman Empire did not fully recover from the Little Ice Age for around a hundred years.

• 7. Beyond Europe's Horizon

  ›

  In North America, the colonists at Roanoke arrived during the largest drought of the past 800 years, as identified by tree ring studies from the University of Arkansas. That drought decreased Native American food supplies, creating conflict; English colonists forced the people of Ossomocomuck to share their depleted stores, leading to warfare and the destruction of Native American towns. In the winter of 1780, New York Harbor froze, allowing people to walk from Manhattan to Staten Island.

  In 1879, the naturalist John Muir found that Glacier Bay ice had retreated 48 miles. The famed naturalist was measuring the aftermath of an era that had, by the late 19th century, mapped the advance of mountain glaciers across the northern and southern temperate zones.

  In Africa, the city of Timbuktu, a key stop on the trans-Saharan caravan route, was flooded at least 13 times by the Niger River during the Little Ice Age, with no records of similar flooding before or since. In Southern Africa, sediment cores from Lake Malawi show colder conditions between 1570 and 1820. A stalagmite record spanning 1690 to 1740 suggests South Africa may have been the coldest region in Africa during that period, possibly cooling by as much as 1.4 degrees Celsius in summer.

  On Easter Island, independent multiproxy analyses of Raraku Lake point to two phases of arid climate: the second running from 1570 to 1720, bracketing the period that coincides with the peak of the Rapa Nui civilization, which flourished during the humid interval from 1200 to 1570 that separated them. The Franz Josef Glacier on New Zealand's west coast advanced rapidly during the Little Ice Age, thrust into a rainforest, and reached its maximum extent in the early 18th century, one of the few documented cases of a glacier advancing into such terrain.

• 8. Causes and Consequences

  ›

  Scientists have proposed at least seven possible causes for the Little Ice Age: orbital cycles, decreased solar activity, increased volcanic activity, altered ocean circulation, fluctuations in human population affecting forest cover, inherent climate variability, and population collapses from events such as the Black Death and the epidemics that spread through the Americas after European contact.

  Volcanic activity has emerged as a particularly strong candidate. A 2012 paper by Miller et al. linked the onset of the Little Ice Age to an unusual 50-year episode featuring four large sulfur-rich explosive eruptions, each releasing global sulfate loading exceeding 60 teragrams. A tropical eruption in 1257, possibly Mount Samalas near Mount Rinjani in Lombok, Indonesia, followed by three smaller eruptions in 1268, 1275, and 1284, prevented the climate from recovering. The 1452/1453 mystery eruption then triggered a second pulse of cooling. The 1815 eruption of Tambora, also in Indonesia, blanketed the atmosphere with ash; the following year became known as the Year Without a Summer, when frost and snow were reported in June and July across New England and Northern Europe.

  Solar activity in the intervals 1400-1550, known as the Spörer Minimum, and 1645-1715, known as the Maunder Minimum, reached very low recorded levels. A 1999 study by Judith Lean found a 0.13 percent increase in total solar irradiance over 1650-1790 that could have raised Earth's temperature by 0.3 degrees Celsius. Numerical climate modelling, however, indicates that volcanic activity was the greater driver of the overall lower temperatures, and the Central England Temperature record, the longest instrumental temperature series in the world, extending continuously back to 1659, shows that the coldest winter in the entire dataset is 1684, the year of one of the most famous Thames frost fairs, yet the fifth warmest winter in the whole series occurred just two years later, in 1686. That variability argues against unremitting cold and toward a picture of sharp, repeating extremes. The Black Death alone may have killed between 30 and 60 percent of the European population, reducing the world population from an estimated 475 million to between 350 and 375 million in the 14th century, and it took 200 years for that population to recover.