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The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true
ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...
of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Matthes described glaciers in the
Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primar ...
of
California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
that he believed could not have survived the hypsithermal; his usage of "Little Ice Age" has been superseded by " Neoglaciation".
The period has been conventionally defined as extending from the 16th to the 19th centuries, (noted in Grove 2004:4). but some experts prefer an alternative timespan from about 1300 to about 1850. The NASA Earth Observatory notes three particularly cold intervals. One began about 1650, another about 1770, and the last in 1850, all of which were separated by intervals of slight warming. The
Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to advance scientific knowledge about climate change caused by human activities. The World Meteorological Organization (WMO) ...
Third Assessment Report The IPCC Third Assessment Report (TAR), ''Climate Change 2001'', is an assessment of available scientific and socio-economic information on climate change by the IPCC. Statements of the IPCC or information from the TAR are often used as a referen ...
considered that the timing and the areas affected by the Little Ice Age suggested largely independent regional climate changes, rather than a globally synchronous increased glaciation. At most, there was modest cooling of the
Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
during the period. Several causes have been proposed: cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, variations in Earth's orbit and
axial tilt In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orb ...
(
orbital forcing Orbital forcing is the effect on climate of slow changes in the tilt of the Earth's axis and shape of the Earth's orbit around the sun (see Milankovitch cycles). These orbital changes modify the total amount of sunlight reaching the Earth by up ...
), inherent variability in global climate, and decreases in the human population (such as from the
Black Death The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Western Eurasia and North Africa from 1346 to 1353. It is the most fatal pandemic recorded in human history, causi ...
and the epidemics emerging in the Americas upon European contact).


Areas involved

The
Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to advance scientific knowledge about climate change caused by human activities. The World Meteorological Organization (WMO) ...
Third Assessment Report The IPCC Third Assessment Report (TAR), ''Climate Change 2001'', is an assessment of available scientific and socio-economic information on climate change by the IPCC. Statements of the IPCC or information from the TAR are often used as a referen ...
(TAR) of 2001 described the areas that were affected: The IPCC Fourth Assessment Report (AR4) of 2007 discusses more recent research and gives particular attention to the Medieval Warm Period:
...when viewed together, the currently available reconstructions indicate generally greater variability in centennial time scale trends over the last 1 kyr than was apparent in the TAR.... The result is a picture of relatively cool conditions in the seventeenth and early nineteenth centuries and warmth in the eleventh and early fifteenth centuries, but the warmest conditions are apparent in the twentieth century. Given that the confidence levels surrounding all of the reconstructions are wide, virtually all reconstructions are effectively encompassed within the uncertainty previously indicated in the TAR. The major differences between the various proxy reconstructions relate to the magnitude of past cool excursions, principally during the twelfth to fourteenth, seventeenth and nineteenth centuries.AR4 WG1 Section 6.6: The Last 2,000 Years
2007.


Dating

There is no consensus on when the Little Ice Age began, but a series of events before the known climatic minima have often been referenced. In the 13th century,
pack ice Drift ice, also called brash ice, is sea ice that is not attached to the shoreline or any other fixed object (shoals, grounded icebergs, etc.).Leppäranta, M. 2011. The Drift of Sea Ice. Berlin: Springer-Verlag. Unlike fast ice, which is "faste ...
began advancing southwards in the
North Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe a ...
, as did
glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...
in
Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland ...
. Anecdotal evidence suggests expanding glaciers almost worldwide. Based on radiocarbon dating of roughly 150 samples of dead plant material with roots intact that were collected from beneath ice caps on
Baffin Island Baffin Island (formerly Baffin Land), in the Canadian territory of Nunavut, is the largest island in Canada and the fifth-largest island in the world. Its area is , slightly larger than Spain; its population was 13,039 as of the 2021 Canadia ...
and
Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...
, Miller ''et al.'' (2012) state that cold summers and ice growth began abruptly between 1275 and 1300, followed by "a substantial intensification" from 1430 to 1455. In contrast, a climate reconstruction based on glacial length shows no great variation from 1600 to 1850 but a strong retreat thereafter. Therefore, any of several dates ranging over 400 years may indicate the beginning of the Little Ice Age: * 1250 for when
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
pack ice Drift ice, also called brash ice, is sea ice that is not attached to the shoreline or any other fixed object (shoals, grounded icebergs, etc.).Leppäranta, M. 2011. The Drift of Sea Ice. Berlin: Springer-Verlag. Unlike fast ice, which is "faste ...
began to grow, a cold period that was possibly triggered or enhanced by the massive eruption of Samalas volcano in 1257 and the associated
volcanic winter A volcanic winter is a reduction in global temperatures caused by volcanic ash and droplets of sulfuric acid and water obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, particularly explosiv ...
. * 1275 to 1300 for when the radiocarbon dating of plants shows that they were killed by glaciation * 1300 for when warm summers stopped being dependable in Northern Europe * 1315 for when rains and the Great Famine of 1315–1317 occurred * 1560 to 1630 for when the worldwide glacial expansion, known as the Grindelwald Fluctuation, began * 1650 for when the first climatic minimum occurred The Little Ice Age ended in the latter half of the 19th century or in the early 20th century. The 6th report of the IPCC describes the coldest period in the last millennium as:


By region


Europe

The
Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...
froze over twice, in 1303 and 1306–1307, and years followed of "unseasonable cold, storms and rains, and a rise in the level of the Caspian Sea.” The Little Ice Age brought colder winters to parts of
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
and
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
. Farms and villages in the
Swiss Alps The Alpine region of Switzerland, conventionally referred to as the Swiss Alps (german: Schweizer Alpen, french: Alpes suisses, it, Alpi svizzere, rm, Alps svizras), represents a major natural feature of the country and is, along with the Swis ...
were destroyed by encroaching glaciers during the mid-17th century. Canals and rivers in
Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It ...
and the
Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...
were frequently frozen deeply enough to support ice skating and winter festivals. The first River Thames frost fair was in 1608 and the last in 1814. Changes to the bridges and the addition of the Thames Embankment have affected the river's flow and depth and greatly diminish the possibility of further freezes. In 1658, a Swedish army marched across the Great Belt to Denmark to attack
Copenhagen Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan a ...
. The winter of 1794–1795 was particularly harsh: the French invasion army under
Pichegru Jean-Charles Pichegru (, 16 February 1761 – 5 April 1804) was a French general of the Revolutionary Wars. Under his command, French troops overran Belgium and the Netherlands before fighting on the Rhine front. His royalist positions led to h ...
marched on the frozen rivers of the Netherlands, and the Dutch fleet was locked in the ice in Den Helder harbour. Sea ice surrounding
Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...
extended for miles in every direction and closed harbors to shipping. The population of Iceland fell by half, but that may have been caused by skeletal fluorosis after the eruption of Laki in 1783. Iceland also suffered failures of cereal crops and people moved away from a grain-based diet. The Norse colonies in
Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland ...
had starved and vanished by the early 15th century because of crop failures and the inability for livestock to be maintained throughout increasingly harsh winters. Greenland was largely cut off by ice from 1410 to the 1720s. In his 1995 book, the early climatologist
Hubert Lamb Hubert Horace Lamb (22 September 1913 in Bedford – 28 June 1997 in Holt, Norfolk) was an English climatologist who founded the Climatic Research Unit in 1972 in the School of Environmental Sciences at the University of East Anglia. Caree ...
said that in many years, "snowfall was much heavier than recorded before or since, and the snow lay on the ground for many months longer than it does today." In
Lisbon Lisbon (; pt, Lisboa ) is the capital and largest city of Portugal, with an estimated population of 544,851 within its administrative limits in an area of 100.05 km2. Lisbon's urban area extends beyond the city's administrative limits w ...
, Portugal, snowstorms were much more frequent than today, and one winter in the 17th century produced eight snowstorms. Many springs and summers were cold and wet but with great variability between years and groups of years. That was particularly evident during the "Grindelwald Fluctuation" (1560–1630); the rapid cooling phase was associated with more erratic weather, including increased storminess, unseasonal snowstorms, and droughts. Crop practices throughout Europe had to be altered to adapt to the shortened and less reliable growing season, and there were many years of scarcity and
famine A famine is a widespread scarcity of food, caused by several factors including war, natural disasters, crop failure, population imbalance, widespread poverty, an economic catastrophe or government policies. This phenomenon is usually accompan ...
. One was the Great Famine of 1315–1317, but that may have been before the Little Ice Age. According to Elizabeth Ewan and Janay Nugent, "Famines in France 1693–94, Norway 1695–96 and Sweden 1696–97 claimed roughly 10 percent of the population of each country. In Estonia and Finland in 1696–97, losses have been estimated at a fifth and a third of the national populations, respectively."
Viticulture Viticulture (from the Latin word for '' vine'') or winegrowing (wine growing) is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of '' Vitis vinifera'', the common grape vine, r ...
disappeared from some northern regions, and storms caused serious flooding and loss of life. Some of them resulted in the permanent loss of large areas of land from the Danish, German, and Dutch coasts. The violinmaker Antonio Stradivari produced his instruments during the Little Ice Age. The colder climate may have caused the wood that was used in his violins to be denser than in warmer periods and to contribute to the tone of his instruments. According to the science historian James Burke, the period inspired such novelties in everyday life as the widespread use of buttons and button-holes, as well as knitting of custom-made undergarments for the better covering and insulating of the body. Chimneys were invented to replace open fires in the centre of communal halls to allow houses with multiple rooms to have the separation of masters from servants. ''The Little Ice Age'', by the anthropologist
Brian Fagan Brian Murray Fagan (born 1 August 1936) is a prolific British author of popular archaeology books and a professor emeritus of Anthropology at the University of California, Santa Barbara. Biography Fagan was born in England where he received ...
of the University of California at Santa Barbara, describes the plight of European peasants from 1300 to 1850: famines,
hypothermia Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe ...
,
bread riots Food riots may occur when there is a shortage and/or unequal distribution of food. Causes can be food price rises, harvest failures, incompetent food storage, transport problems, food speculation, hoarding, poisoning of food, or attacks by pests ...
and the rise of despotic leaders brutalizing an increasingly-dispirited peasantry. In the late 17th century, agriculture had dropped off dramatically: "Alpine villagers lived on bread made from ground nutshells mixed with
barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley p ...
and oat flour." Historian Wolfgang Behringer has linked intensive
witch-hunting A witch-hunt, or a witch purge, is a search for people who have been labeled witches or a search for evidence of witchcraft. The classical period of witch-hunts in Early Modern Europe and Colonial America took place in the Early Modern perio ...
episodes in Europe to agricultural failures during the Little Ice Age. ''The Frigid Golden Age'', by the environmental historian Dagomar Degroot of
Georgetown University Georgetown University is a private research university in the Georgetown neighborhood of Washington, D.C. Founded by Bishop John Carroll in 1789 as Georgetown College, the university has grown to comprise eleven undergraduate and graduate ...
, points out that some societies thrived, but others faltered during the Little Ice Age. In particular, the Little Ice Age transformed environments around the
Dutch Republic The United Provinces of the Netherlands, also known as the (Seven) United Provinces, officially as the Republic of the Seven United Netherlands ( Dutch: ''Republiek der Zeven Verenigde Nederlanden''), and commonly referred to in historiograph ...
and made them easier to exploit in commerce and conflict. The Dutch were resilient, even adaptive, in the face of weather that devastated neighboring countries. Merchants exploited harvest failures, military commanders took advantage of shifting wind patterns, and inventors developed technologies that helped them profit from the cold. The 17th-century Dutch Golden Age therefore owed much to its people's flexibility in coping with the changing climate.


Cultural responses

Historians have argued that cultural responses to the consequences of the Little Ice Age in Europe consisted of violent scapegoating. The prolonged cold, dry periods brought drought upon many European communities and resulted in poor crop growth, poor livestock survival, and increased activity of pathogens and disease vectors. Disease intensified under the same conditions that unemployment and economic difficulties arose: prolonged cold, dry seasons. Disease and unemployment generated a lethal positive feedback loop. Although the communities had some contingency plans, such as better crop mixes, emergency grain stocks, and international food trade, they did not always prove effective. Communities often lashed out via violent crimes, including robbery and murder. Accusations of sexual offenses also increased, such as
adultery Adultery (from Latin ''adulterium'') is extramarital sex that is considered objectionable on social, religious, moral, or legal grounds. Although the sexual activities that constitute adultery vary, as well as the social, religious, and legal ...
, bestiality, and
rape Rape is a type of sexual assault usually involving sexual intercourse or other forms of sexual penetration carried out against a person without their consent. The act may be carried out by physical force, coercion, abuse of authority, or ...
. Europeans sought explanations for the famine, disease, and social unrest that they were experiencing, and they blamed the innocent. Evidence from several studies indicate that increases in violent actions against marginalized groups, which were held responsible for the Little Ice Age, overlap with the years of particularly cold, dry weather. One example of the violent scapegoating occurring during the Little Ice Age was the resurgence of witchcraft trials. Oster (2004) and Behringer (1999) argue that the resurgence was brought by the climatic decline. Prior to the Little Ice Age, witchcraft was considered an insignificant crime, and victims were rarely accused. But beginning in the 1380s, just as the Little Ice Age began, European populations began to link magic and weather-making. The first systematic witch hunts began in the 1430s, and by the 1480s, it was widely believed that witches should be held accountable for poor weather. Witches were blamed for direct and indirect consequences of the Little Ice Age: livestock epidemics, cows that gave too little milk, late frosts, and unknown diseases. In general, the number of witchcraft trials rose as the temperature dropped, and trials decreased when temperature increased. The peaks of witchcraft persecutions overlap with the hunger crises that occurred in 1570 and 1580, the latter lasting a decade. The trials targeted primarily poor women, many of them widows. Not everybody agreed that witches should be persecuted for weather-making, but such arguments focused primarily not upon whether witches existed but upon whether witches had the capability to control the weather. The
Catholic Church The Catholic Church, also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.3 billion baptized Catholics Catholic Church by country, worldwide . It is am ...
in the
Early Middle Ages The Early Middle Ages (or early medieval period), sometimes controversially referred to as the Dark Ages, is typically regarded by historians as lasting from the late 5th or early 6th century to the 10th century. They marked the start of the Mi ...
argued that witches could not control the weather because they were mortals, not God, but by the mid-13th century, most people agreed with the idea that witches could control natural forces.
Jewish Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...
populations were also blamed for climatic deterioration during the Little Ice Age. The Western European states experienced waves of anti-Semitism, directed against the main religious minority in their otherwise Christian societies. There was no direct link made between Jews and the weather; they were blamed only for indirect consequences such as disease. Outbreaks of the
Black Death The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Western Eurasia and North Africa from 1346 to 1353. It is the most fatal pandemic recorded in human history, causi ...
were often blamed on Jews. In Western European cities during the 1300s, Jewish populations were murdered to stop the spread of the plague. Rumors spread that Jews were either poisoning wells themselves, or telling lepers to poison the wells. To escape persecution, some Jews converted to Christianity, while others migrated to the
Ottoman Empire The Ottoman Empire, * ; is an archaic version. The definite article forms and were synonymous * and el, Оθωμανική Αυτοκρατορία, Othōmanikē Avtokratoria, label=none * info page on book at Martin Luther University ...
,
Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
or the
Holy Roman Empire The Holy Roman Empire was a political entity in Western, Central, and Southern Europe that developed during the Early Middle Ages and continued until its dissolution in 1806 during the Napoleonic Wars. From the accession of Otto I in 962 unt ...
, where they experienced greater toleration. Some populations blamed the cold periods and the resulting famine and disease during the Little Ice Age on a general divine displeasure. Particular groups took the brunt of the burden in attempts to cure it. In Germany, regulations were imposed upon activities such as
gambling Gambling (also known as betting or gaming) is the wagering of something of value ("the stakes") on a random event with the intent of winning something else of value, where instances of strategy are discounted. Gambling thus requires three ele ...
and drinking, which disproportionately affected the lower class and women were forbidden from showing their knees. Other regulations affected the wider population, such as prohibiting
dancing Dance is a performing art form consisting of sequences of movement, either improvised or purposefully selected. This movement has aesthetic and often symbolic value. Dance can be categorized and described by its choreography, by its repertoi ...
, sexual activities and moderating food and drink intake. In Ireland, Catholics blamed the
Reformation The Reformation (alternatively named the Protestant Reformation or the European Reformation) was a major movement within Western Christianity in 16th-century Europe that posed a religious and political challenge to the Catholic Church and in ...
for the bad weather. The '' Annals of Loch Cé'', in its entry for 1588, describes a midsummer snowstorm as "a wild apple was not larger than each stone of it" and blames it on the presence of a "wicked, heretical, bishop in Oilfinn", the
Protestant Protestantism is a Christian denomination, branch of Christianity that follows the theological tenets of the Reformation, Protestant Reformation, a movement that began seeking to reform the Catholic Church from within in the 16th century agai ...
Bishop of Elphin, John Lynch.


Depictions of winter in European painting

William James Burroughs analyzes the depiction of winter in paintings, as does Hans Neuberger. Burroughs asserts that it occurred almost entirely from 1565 to 1665 and was associated with the climatic decline from 1550 onwards. Burroughs claims that there had been almost no depictions of winter in art, and he "hypothesizes that the unusually harsh winter of 1565 inspired great artists to depict highly original images and that the decline in such paintings was a combination of the 'theme' having been fully explored and mild winters interrupting the flow of painting." Wintry scenes, which entail technical difficulties in painting, have been regularly and well handled since at least the early 15th century by artists in
illuminated manuscript An illuminated manuscript is a formally prepared document where the text is often supplemented with flourishes such as borders and miniature illustrations. Often used in the Roman Catholic Church for prayers, liturgical services and psalms, th ...
cycles that show the ''
Labours of the Months The term Labours of the Months refers to cycles in Medieval and early Renaissance art depicting in twelve scenes the rural activities that commonly took place in the months of the year. They are often linked to the signs of the Zodiac, and are ...
'', typically placed on the calendar pages of books of hours. January and February are typically shown as snowy, as in ''February'' in the famous cycle in the , painted in 1412–1416 and illustrated below. Since landscape painting had not yet developed as an independent genre in art, the absence of other winter scenes is not remarkable. On the other hand, snowy winter landscapes, particularly stormy seascapes, became artistic genres in the Dutch Golden Age painting during the coldest and stormiest decades of the Little Ice Age. Most modern scholars believe them to be full of symbolic messages and metaphors, which would have been clear to contemporary viewers. All of the famous winter landscape paintings by
Pieter Brueghel the Elder Pieter Bruegel (also Brueghel or Breughel) the Elder (, ; ; – 9 September 1569) was the most significant artist of Dutch and Flemish Renaissance painting, a painter and printmaker, known for his landscapes and peasant scenes (so-called ge ...
, such as ''
The Hunters in the Snow ''The Hunters in the Snow'' ( nl, Jagers in de Sneeuw), also known as ''The Return of the Hunters'', is a 1565 oil-on-wood painting by Pieter Bruegel the Elder. The Northern Renaissance work is one of a series of works, five of which still survi ...
'' and the '' Massacre of the Innocents'', are thought to have been painted around 1565. His son Pieter Brueghel the Younger (1564–1638) also painted many snowy landscapes, but according to Burroughs, he "slavishly copied his father's designs. The derivative nature of so much of this work makes it difficult to draw any definite conclusions about the influence of the winters between 1570 and 1600....". In addition, Breughel painted ''Hunters in the Snow'' in Antwerp, so the mountains in the picture probably mean it was based on drawings or memories from crossing of the
Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...
during his trip to Rome in 1551-1552. It is one of 5 known surviving paintings, probably from a series of 6 or 12, known as “the Twelve Months”, that Breughel was commissioned to paint by a wealthy patron in
Antwerp Antwerp (; nl, Antwerpen ; french: Anvers ; es, Amberes) is the largest city in Belgium by area at and the capital of Antwerp Province in the Flemish Region. With a population of 520,504,
,
Niclaes Jonghelinck Nicolaes Jonghelinck (1517–1570) was a merchant banker and art collector in Antwerp. He is best known for his collection of paintings by Pieter Bruegel the Elder and Frans Floris. His brother was the sculptor Jacques Jonghelinck. In the archive ...
(''Hunters in the Snow'' being for January): none of the other four that survive show a snow-covered landscape and both ''
The Hay Harvest ''The Hay Harvest'' (also known as ''Haymaking''), is an oil painting on wood panel by Pieter Bruegel (c. 1525–1569), executed in 1565. The most important of the Lobkowicz family's Northern pictures, it was hung in the dining room of the Antwe ...
'' (July) and '' The Harvesters'' (August) depict warm summer days. Even ''
The Return of the Herd ''The Return of the Herd'' is an oil on wood painting by Pieter Bruegel in 1565. The painting is one in a series of six works (High Springtime is presumed lost) that depict different seasons. The painting is currently in the collection of the Ku ...
'' (thought to be the painting for November) and ''
The Gloomy Day ''The Gloomy Day'' is an oil on wood painting by Pieter Bruegel in 1565. The painting is one in a series of six works, five of which are still extant, that depict different times of the year. The painting is currently in the collection of the K ...
'' (known to be for February) show landscapes free of snow. Burroughs says that snowy subjects return to Dutch Golden Age painting with works by
Hendrick Avercamp Hendrick Avercamp (January 27, 1585 (bapt.) – May 15, 1634 (buried)) was a Dutch painter during the Dutch Golden Age of painting. He was one of the earliest landscape painters of the 17th-century Dutch school, he specialized in painting th ...
from 1609 onwards. There is a hiatus between 1627 and 1640, which is before the main period of such subjects from the 1640s to the 1660s. That relates well with climate records for the later period. The subjects are less popular after about 1660, but that does not match any recorded reduction in severity of winters and may reflect only changes in taste or fashion. In the later period between the 1780s and 1810s, snowy subjects again became popular. Neuberger analyzed 12,000 paintings, held in American and European museums and dated between 1400 and 1967, for cloudiness and darkness. His 1970 publication shows an increase in such depictions that corresponds to the Little Ice Age, which peaks between 1600 and 1649. Paintings and contemporary records in Scotland demonstrate that
curling Curling is a sport in which players slide stones on a sheet of ice toward a target area which is segmented into four concentric circles. It is related to bowls, boules, and shuffleboard. Two teams, each with four players, take turns slidi ...
and ice skating were popular outdoor winter sports, with curling dating back to the 16th century and becoming widely popular in the mid-19th century. An outdoor curling pond constructed in Gourock in the 1860s remained in use for almost a century, but increasing use of indoor facilities, problems of vandalism, and milder winters led to the pond being abandoned in 1963.


General Crisis of the seventeenth century

The General Crisis of the seventeenth century in Europe was a period of inclement weather, crop failure, economic hardship, extreme intergroup violence, and high mortality linked to the Little Ice Age. Episodes of social instability track the cooling with a time lapse of up to 15 years, and many developed into armed conflicts, such as the
Thirty Years' War The Thirty Years' War was one of the longest and most destructive conflicts in European history, lasting from 1618 to 1648. Fought primarily in Central Europe, an estimated 4.5 to 8 million soldiers and civilians died as a result of batt ...
(1618–1648). The war started as a war of succession to the Bohemian throne. Animosity between Protestants and Catholics in the Holy Roman Empire (now Germany) added fuel to the fire. It soon escalated to a huge conflict that involved all the major European powers and devastated much of Germany. When the war ended, some regions of the Holy Roman Empire had seen their population drop by as much as 70%. However, as global temperatures started to rise, the ecological stress faced by Europeans also began to fade. Mortality rates dropped, and the level of violence fell. This helped lead to the Enlightenment, which witnessed the emergence of innovations in technology (which enabled industrialization), medicine (which improved hygiene), and social welfare (such as the world's first welfare programs in Germany) and made life even more comfortable.


North America

Early European explorers and settlers of North America reported exceptionally severe winters. For example, according to Lamb, Samuel Champlain reported bearing ice along the shores of
Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
in June 1608. Both Europeans and indigenous peoples suffered excess mortality in
Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and nor ...
during the winter of 1607–08, and extreme frost was meanwhile reported in the Jamestown, Virginia, settlement. Native Americans formed leagues in response to food shortages. The journal of Pierre de Troyes, Chevalier de Troyes, who led an expedition to
James Bay James Bay (french: Baie James; cr, ᐐᓂᐯᒄ, Wînipekw, dirty water) is a large body of water located on the southern end of Hudson Bay in Canada. Both bodies of water extend from the Arctic Ocean, of which James Bay is the southernmost p ...
in 1686, recorded that the bay was still littered with so much floating ice that he could hide behind it in his canoe on 1 July. In the winter of 1780,
New York Harbor New York Harbor is at the mouth of the Hudson River where it empties into New York Bay near the East River tidal estuary, and then into the Atlantic Ocean on the east coast of the United States. It is one of the largest natural harbors in ...
froze, which allowed people to walk from Manhattan Island to
Staten Island Staten Island ( ) is a Boroughs of New York City, borough of New York City, coextensive with Richmond County, in the U.S. state of New York (state), New York. Located in the city's southwest portion, the borough is separated from New Jersey b ...
. The extent of mountain glaciers had been mapped by the late 19th century. In the north and the south temperate zones, Equilibrium Line Altitude (the boundaries separating zones of net accumulation from those of net ablation) were about lower than they were in 1975. In Glacier National Park, the last episode of glacier advance came in the late 18th and the early 19th centuries. In 1879, the famed naturalist
John Muir John Muir ( ; April 21, 1838December 24, 1914), also known as "John of the Mountains" and "Father of the National Parks", was an influential Scottish-American naturalist, author, environmental philosopher, botanist, zoologist, glaciologis ...
found that Glacier Bay ice had retreated . In
Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...
,
Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean t ...
, large temperature excursions were possibly related to changes in the strength of North Atlantic thermohaline circulation. Because the Little Ice Age took place during the
European colonization of the Americas During the Age of Discovery, a large scale European colonization of the Americas took place between about 1492 and 1800. Although the Norse had explored and colonized areas of the North Atlantic, colonizing Greenland and creating a short t ...
, it discouraged many early colonizers, who had expected the climate of North America to be similar to the climate of Europe at similar latitudes. They found that North America, at least in what would become Canada and the northern United States, had hotter summers and colder winters than Europe. That effect was aggravated by the Little Ice Age, and unpreparedness led to the collapse of many early European settlements in North America. Historians agree that when colonists settled at Jamestown, it was one of the coldest periods in the last 1000 years. Drought was also a problem in North America during the Little Ice Age, and the settlers arrived in Roanoke during the largest drought of the past 800 years. Tree ring studies by the University of Arkansas discovered that many colonists arrived at the beginning of a seven-year drought. The droughts also decreased the Native American populations and led to conflict because of food scarcity. English colonists at Roanoke forced Native Americans of Ossomocomuck to share their depleted supplies with them. That led to warfare between the two groups, and Native American cities were destroyed. That cycle would repeat itself many times at Jamestown. The combination of fighting and cold weather also led to the spread of diseases. The colder weather helped the parasites brought by Europeans in mosquitoes to develop faster. That in turn led to many malaria deaths among Native Americans. In 1642, Thomas Gorges wrote that between 1637 and 1645, colonists in Maine (then part of Massachusetts) experienced horrendous weather conditions. In June 1637, temperatures were so high that numerous European settlers died; travelers were forced to travel at night to stay cool. Gorges also wrote that the winter of 1641–42 was “piercingly Intolerable” and that no Englishman or Native American had ever seen anything like it. He also stated that the Massachusetts Bay had frozen as far as one could see, and that horse carriages now roamed where ships used to be. He stated that the summers of 1638 and 1639 were very short, cold, and wet, which compounded food scarcity for a few years. To make matters worse, creatures like caterpillars and pigeons fed on crops and devastated harvests. Every year about which Gorges wrote featured unusual weather patterns, including high precipitation, drought, and extreme cold or heat. Many inhabitants of North America had their own theories about the extreme weather. The colonist
Ferdinando Gorges Sir Ferdinando Gorges ( – 24 May 1647) was a naval and military commander and governor of the important port of Plymouth in England. He was involved in Essex's Rebellion against the Queen, but escaped punishment by testifying against the mai ...
blamed the cold weather on cold ocean winds. Humphrey Gilbert tried to explain Newfoundland's icy and foggy weather by saying that the Earth drew cold vapors from the ocean and drew them west. Many others had their own theories for North America being so much colder than Europe; their observations and hypotheses offer insight on the Little Ice Age's effects in North America.


Mesoamerica

An analysis of several climate proxies undertaken in Mexico's Yucatán Peninsula, which was linked by its authors to Maya and
Aztec The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl ...
chronicles relating periods of cold and drought, supports the existence of the Little Ice Age in the region. Another study conducted in several sites in Mesoamerica like Los Tuxtlas and Lake Pompal in Veracruz, Mexico show a decrease in human activity in the area during the Little Ice Age. That was proven by studying charcoal fragments and the amount of maize pollen taken from sedimentary samples by using a nonrotatory piston corer. The samples also showed volcanic activity which caused forest regeneration between 650 and 800. The instances of volcanic activity near Lake Pompal indicate varying temperatures, not a continuous coldness, during the Little Ice Age in Mesoamerica.


Atlantic Ocean

In the North Atlantic, sediments accumulated since the end of the last ice age, which occurred nearly 12,000 years ago, show regular increases in the amount of coarse sediment grains deposited from icebergs melting in the now-open ocean, indicating a series of 1–2 °C (2–4 °F) cooling events that recur every 1,500 years or so. The most recent cooling event was the Little Ice Age. The same cooling events are detected in sediments accumulating off Africa, but the cooling events appear to be larger: 3–8 °C (6–14 °F).


Asia

Although the original designation of a Little Ice Age referred to the reduced temperature of Europe and North America, there is some evidence of extended periods of cooling outside those regions although it is not clear whether they are related or independent events. Mann states:
While there is evidence that many other regions outside Europe exhibited periods of cooler conditions, expanded glaciation, and significantly altered climate conditions, the timing and nature of these variations are highly variable from region to region, and the notion of the Little Ice Age as a globally synchronous cold period has all but been dismissed.
In China, warm-weather crops such as oranges were abandoned in Jiangxi Province, where they had been grown for centuries. Also, the two periods of most frequent
typhoon A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for a ...
strikes in
Guangdong Guangdong (, ), alternatively romanized as Canton or Kwangtung, is a coastal province in South China on the north shore of the South China Sea. The capital of the province is Guangzhou. With a population of 126.01 million (as of 2020 ...
coincide with two of the coldest and driest periods in northern and central China (1660–1680, 1850–1880). Scholars have argued that one of the reasons for the
fall of the Ming dynasty The transition from Ming to Qing, alternatively known as Ming–Qing transition or the Manchu conquest of China, from 1618 to 1683, saw the transition between two major dynasties in Chinese history. It was a decades-long conflict between the e ...
may have been the droughts and famines that were caused by the Little Ice Age. There are debates on the start date and the periods of Little Ice Age's effects. Most scholars agree on categorizing the Little Ice Age period into three distinct cold periods: in 1458–1552, 1600–1720, and 1840–1880. According to data from the
National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditi ...
, the eastern
monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...
area of China was the earliest to experience the effects of the Little Ice Age, from 1560 to 1709. In the western region of China surrounding the
Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the Ti ...
, the effects of the Little Ice Age lagged behind the eastern region, with significant cold periods from 1620 to 1749. Southwestern China became significantly colder and drier as a result of the weakening of the Asian Summer Monsoon caused by the decreased pressure gradient resulting from the cooling of the southern Eurasian landmass, while northwestern China, dominated by westerlies, saw an increase in precipitation. The temperature changes were unprecedented for the farming communities in China. According to
Coching Chu Coching Chu (; March 7, 1890 – February 7, 1974) was a Chinese geologist and meteorologist. Born in Shangyu, Zhejiang, Chu went to United States for his college education in 1910. He graduated from the College of Agriculture, University o ...
's 1972 study, the Little Ice Age from the end of the Ming dynasty to the start of the Qing dynasty (1650–1700) was one of the coldest periods in recorded Chinese history. Many major droughts during the summer months were recorded, and significant freezing events occurred during the winter months. That greatly worsened the food supply during the Ming dynasty. This period of Little Ice Age corresponded to the period's major historical events. The Jurchen people lived in Northern China and formed a tributary state to the Ming dynasty and its Wanli Emperor. From 1573 to 1620, Manchuria experienced famine caused by extreme snowfall, which depleted agriculture production and decimated the livestock population. Scholars have argued that it had been caused by the temperature drops during the Little Ice Age. Despite the lack of food production, the Wanli Emperor ordered the Jurchens to pay the same amount of tribute each year. That led to anger and sowed seeds to the rebellion against the Ming dynasty. In 1616, Jurchens established the Later Jin dynasty. Led by Hong Taiji and Nurhaci, the Later Jin dynasty moved South and achieved decisive victories in battles against the Ming dynasty's military, such as during the 1618 Battle of Fushun. After the earlier defeats and the death of the Wanli Emperor, the
Chongzhen Emperor The Chongzhen Emperor (; 6 February 1611 – 25 April 1644), personal name Zhu Youjian (), courtesy name Deyue (),Wang Yuan (王源),''Ju ye tang wen ji'' (《居業堂文集》), vol. 19. "聞之張景蔚親見烈皇帝神主題御諱字德� ...
took over China and continued the war effort. From 1632 to 1641, the Little Ice Age began to cause drastic climate changes in the Ming dynasty's territories. For example, rainfall in the Huabei region dropped by 11% to 47% from the historical average. Meanwhile, the
Shaanbei Shaanbei () or Northern Shaanxi is the portion of China's Shaanxi province north of the Huanglong Mountain and the Meridian Ridge (the so-called " Guanzhong north mountains"), and is both a geographic as well as a cultural area. It makes up the ...
region, along the
Yellow River The Yellow River or Huang He (Chinese: , Mandarin: ''Huáng hé'' ) is the second-longest river in China, after the Yangtze River, and the sixth-longest river system in the world at the estimated length of . Originating in the Bayan Ha ...
experienced six major floods, which ruined cities such as Yan’an. The climate factored heavily in weakening the government's control over China and accelerated the fall of the Ming dynasty. In 1644,
Li Zicheng Li Zicheng (22 September 1606 – 1645), born Li Hongji, also known by the nickname, Dashing King, was a Chinese peasant rebel leader who overthrew the Ming dynasty in 1644 and ruled over northern China briefly as the emperor of the short-li ...
led the Later Jin's forces into
Beijing } Beijing ( ; ; ), Chinese postal romanization, alternatively romanized as Peking ( ), is the Capital city, capital of the China, People's Republic of China. It is the center of power and development of the country. Beijing is the world's Li ...
, overthrew the Ming dynasty, and established the
Qing dynasty The Qing dynasty ( ), officially the Great Qing,, was a Manchu-led imperial dynasty of China and the last orthodox dynasty in Chinese history. It emerged from the Later Jin dynasty founded by the Jianzhou Jurchens, a Tungusic-speak ...
. During the early years of the Qing dynasty, the Little Ice Age continued to have a significant impact on Chinese society. During the rule of the
Kangxi Emperor The Kangxi Emperor (4 May 1654– 20 December 1722), also known by his temple name Emperor Shengzu of Qing, born Xuanye, was the third emperor of the Qing dynasty, and the second Qing emperor to rule over China proper, reigning from 1661 to ...
(1661–1722), most Qing territories were still much colder than the historical average. However, the Kangxi Emperor pushed reforms and managed to increase the socio-economic recovery from the natural disasters. He benefited partly from the peacefulness of the early Qing dynasty. That essentially marked the end of the Little Ice Age in China and led to a more prosperous era of Chinese history that is known as the High Qing era. In the
Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...
, the general assumption is that the cooling events were synchronous with those in Europe during the Little Ice Age because of the characteristics of moraines. However, applications of Quaternary dating methods such as surface exposure dating have showed that glacial maxima occurred between 1300 and 1600, slightly earlier than the recorded coldest period in the Northern Hemisphere. Many large Himalayan glacial debris fields have remained close to their limits since the Little Ice Age. The Himalayas also experienced an increase in snowfall at higher altitudes, which results in a southward shift in the Indian summer monsoon and an increase in precipitation. Overall, the increase in winter precipitation may have caused some glacial movements. Since the end of the Little Ice Age, there has been an almost continuous retreat of glaciers to present. In India, the region in
Balochistan Balochistan ( ; bal, بلۏچستان; also romanised as Baluchistan and Baluchestan) is a historical region in Western and South Asia, located in the Iranian plateau's far southeast and bordering the Indian Plate and the Arabian Sea coastline. ...
became colder, and its native
Baloch people The Baloch or Baluch ( bal, بلۏچ, Balòc) are an Iranian people who live mainly in the Balochistan region, located at the southeasternmost edge of the Iranian plateau, encompassing the countries of Pakistan, Iran, and Afghanistan. There a ...
started a
mass migration Mass migration refers to the migration of large groups of people from one geographical area to another. Mass migration is distinguished from individual or small-scale migration; and also from seasonal migration, which may occur on a regular basis ...
and began to settle along the
Indus River The Indus ( ) is a transboundary river of Asia and a trans-Himalayan river of South and Central Asia. The river rises in mountain springs northeast of Mount Kailash in Western Tibet, flows northwest through the disputed region of Kashmi ...
in
Sindh Sindh (; ; ur, , ; historically romanized as Sind) is one of the four provinces of Pakistan. Located in the southeastern region of the country, Sindh is the third-largest province of Pakistan by land area and the second-largest province ...
and
Punjab Punjab (; Punjabi Language, Punjabi: پنجاب ; ਪੰਜਾਬ ; ; also Romanization, romanised as ''Panjāb'' or ''Panj-Āb'') is a geopolitical, cultural, and historical region in South Asia, specifically in the northern part of the I ...
.


Africa

The Little Ice Age influenced the African climate from the 14th to the 19th centuries. Despite variances throughout the continent, a general trend of declining temperatures in Africa led to an average cooling of 1 °C. In Ethiopia and North Africa, permanent snow was reported on mountain peaks at levels at which it does not occur today.
Timbuktu Timbuktu ( ; french: Tombouctou; Koyra Chiini: ); tmh, label=Tuareg, script=Tfng, ⵜⵏⴱⴾⵜ, Tin Buqt a city in Mali, situated north of the Niger River. The town is the capital of the Tombouctou Region, one of the eight administrativ ...
, an important city on the trans-
Sahara , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...
n caravan route, was flooded at least 13 times by the
Niger River The Niger River ( ; ) is the main river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in south-eastern Guinea near the Sierra Leone border. It runs in a crescent shape through Mal ...
, but there are no records of similar flooding before or since that time. Several paleoclimatic studies of Southern Africa have suggested significant changes in relative changes in climate and environmental conditions. In Southern Africa, sediment cores retrieved from
Lake Malawi Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest f ...
show colder conditions between 1570 and 1820, which "further support, and extend, the global expanse of the Little Ice Age." A novel 3,000-year temperature reconstruction method, based on the rate of
stalagmite A stalagmite (, ; from the Greek , from , "dropping, trickling") is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites are typicall ...
growth in a cold cave in
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
, further suggests a cold period from 1500 to 1800 "characterizing the South African Little Ice age." The δ18O stalagmite record temperature reconstruction over a 350-year period (1690–1740) suggests that South Africa may have been the coldest region in Africa and have cooled by as much as 1.4 °C in summer. Also, the solar magnetic and Niño-Southern Oscillation cycles may have been key drivers of climate variability in the subtropical region. Periglacial features in the eastern Lesotho Highlands might have been reactivated by the Little Ice Age. Another archaeological reconstruction of South Africa reveals the rise of the Great Zimbabwe people because of ecological advantages from the increased rainfall over other competitor societies, such as the Mupungubwe people. Pollen records derived from
rock hyrax The rock hyrax (; ''Procavia capensis''), also called dassie, Cape hyrax, rock rabbit, and (in the King James Bible) coney, is a medium-sized terrestrial mammal native to Africa and the Middle East. Commonly referred to in South Africa as the ...
middens in the
Cederberg Mountains The Cederberg mountains are located near Clanwilliam, approximately 300 km north of Cape Town, South Africa at about . The mountain range is named after the endangered Clanwilliam cedar (''Widdringtonia wallichii''), which is a tree en ...
of southwestern South Africa indicate an increase in humidity in the region at the start of the Little Ice Age. Other than temperature variability, data from equatorial East Africa suggest impacts to the hydrologic cycle in the late 1700s. Historical data reconstructions from ten major African lakes indicate that an episode of “drought and desiccation” occurred throughout East Africa. The period showed drastic reductions in the depths of lakes, which were transformed into desiccated puddles. It is very likely that locals could cross Lake Chad, among others, and that bouts of “intense droughts were ubiquitous.” That indicates local societies were probably launched into long migrations and warfare with neighboring tribes, since agriculture was made virtually useless by the dry soil.


Antarctica

Kreutz et al. (1997) compared results from studies of West Antarctic ice cores with the Greenland Ice Sheet Project Two GISP2; they suggested a synchronous global cooling. An ocean sediment core from the eastern Bransfield Basin in the Antarctic Peninsula shows centennial events, which the authors link to the Little Ice Age and to the Medieval Warm Period. The authors note that "other unexplained climatic events comparable in duration and amplitude to the LIA and MWP events also appear." The
Siple Dome Siple Dome () is an ice dome approximately 100 km wide and 100 km long, located 130 km east of Siple Coast in Antarctica. Charles Bentley and Robert Thomas established a "strain rosette" on this feature to determine ice movement in ...
(SD) had a climate event with an onset time that is coincident with that of the Little Ice Age in the North Atlantic, based on a correlation with the GISP2 record. The Little Ice Age is the most dramatic climate event in the SD Holocene glaciochemical record. The Siple Dome ice core also contained its highest rate of melt layers (up to 8%) between 1550 and 1700, most likely because of warm summers.
Law Dome Law Dome is a large ice dome which rises to directly south of Cape Poinsett, Antarctica. The feature was roughly mapped by the United States Geological Survey from aerial photographs taken by U.S. Navy Operation Highjump, 1946–47, and has been ...
ice cores show lower levels of CO2 mixing ratios from 1550 to 1800, which Etheridge and Steele believe to be "probably as a result of colder global climate." Sediment cores in Bransfield Basin, Antarctic Peninsula, have neoglacial indicators by diatom and sea-ice taxa variations during the Little Ice Age. Stable isotope records from the Mount Erebus Saddle ice core site suggests that the Ross Sea region experienced average temperatures 1.6 ± 1.4 °C cooler during the Little Ice Age than the last 150 years.


Australia and New Zealand

Its location in the Southern Hemisphere made Australia not experience a regional cooling like that of Europe or North America. Instead, the Australian Little Ice Age was characterized by humid, rainy climates, which were followed by drying and aridification in the 19th century.Tibby, J; Tyler, JJ; Barr, C. �
Post little ice age drying of eastern Australia conflates understanding of early settlement impacts.
�� Quaternary Science Reviews. Vol. 202 (15 December 2018): 45–54.
As studied by Tibby et al. (2018), lake records from Victoria,
New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...
, and
Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...
suggest that conditions in the east and the south-east of Australia were wet and unusually cool from the 16th to the early 19th centuries. That corresponds with the “peak” of the global Little Ice Age from 1594 to 1722. For example, the Swallow Lagoon rainfall record indicates that from c. 1500–1850, there was significant and consistent rainfall, which sometimes exceeded 300 mm. The rainfalls significantly reduced after around 1890. Similarly, the hydrological records of Lake Surprise's
salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...
levels reveal high humidity levels around from 1440 to 1880, and an increase in salinity from 1860 to 1880 points to a negative change to the once-humid climate. The mid-19th century marked a notable change to eastern Australia's rainfall and humidity patterns. Tibby et al. (2018) note that in eastern Australia, the paleoclimatic changes of the Little Ice Age in the late 1800s coincided with the agricultural changes resulting from European colonization. After the 1788 establishment of British colonies in the Australia, which were concentrated primarily in the eastern regions and cities like Sydney and later Melbourne and Brisbane, the British introduced new agricultural practices like
pastoralism Pastoralism is a form of animal husbandry where domesticated animals (known as "livestock") are released onto large vegetated outdoor lands ( pastures) for grazing, historically by nomadic people who moved around with their herds. The anim ...
. Such practices required widespread deforestation and clearance of vegetation. Pastoralism and the clearing of land are captured in works of art such as the 1833 painting by the prominent landscape artist John Glover ''Patterdale Landscape with Cattle''. Over the next century, the deforestation led to a loss of biodiversity, wind and water-based soil erosion, and soil salinity. Furthermore, as argued by Gordan et al. (2003), such land and vegetation clearance in Australia resulted in a 10% reduction in the transport of water vapor to the atmosphere. That occurred in Western Australia as well, where 19th-century land clearing resulted in reduced rainfall over the region. By 1850 to 1890, those human agricultural practices, which were concentrated in eastern Australia, had most likely amplified the drying and aridification that marked the end of the Little Ice Age. In the north, evidence suggests fairly dry conditions, but coral cores from the
Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, A ...
show rainfall similar to today but with less variability. A study that analyzed isotopes in Great Barrier Reef corals suggested that increased water vapor transport from the southern tropical oceans to the poles contributed to the Little Ice Age. Borehole reconstructions from Australia suggest that over the last 500 years, the 17th century was the coldest on the continent. The borehole temperature reconstruction method further indicates that the warming of Australia over the past five centuries is only around half that of the warming experienced by the Northern Hemisphere, which further proves that Australia did not reach the same depths of cooling as the continents in the north. On the west coast of the Southern Alps of New Zealand, the
Franz Josef Glacier The Franz Josef Glacier (; officially Franz Josef Glacier / ) is a temperate maritime glacier in Westland Tai Poutini National Park on the West Coast of New Zealand's South Island. Together with the Fox Glacier to the south, and a third glac ...
advanced rapidly during the Little Ice Age and reached its maximum extent in the early 18th century. That was one of the few cases of a glacier thrusting into a rainforest. Evidence suggests, corroborated by tree ring proxy data, that the glacier contributed to a temperature anomaly over the course of the Little Ice Age in New Zealand. Based on dating of a yellow-green lichen of the '' Rhizocarpon'' subgenus, the Mueller Glacier, on the eastern flank of the Southern Alps within Aoraki / Mount Cook National Park, is considered to have been at its maximum extent between 1725 and 1730.


Pacific Islands

Sea-level data for the
Pacific Islands Collectively called the Pacific Islands, the islands in the Pacific Ocean are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of se ...
suggest that sea level in the region fell, possibly in two stages, between 1270 and 1475. That was associated with a 1.5 °C fall in temperature, as determined from oxygen-isotope analysis, and an observed increase in the frequency of El Niño. Tropical Pacific
coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...
records indicate the most frequent and intense
El Niño-Southern Oscillation EL, El or el may refer to: Religion * El (deity), a Semitic word for "God" People * EL (rapper) (born 1983), stage name of Elorm Adablah, a Ghanaian rapper and sound engineer * El DeBarge, music artist * El Franco Lee (1949–2016), American ...
activity was in the mid-17th century.
Foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly ...
ld 18 O records indicate that the Indo-Pacific Warm Pool was warm and saline between 1000 and 1400, with temperatures approximating current conditions, but that it cooled from 1400 onwards and reached its lowest temperatures in 1700. That is consistent with the transition from the mid-
Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...
warming to the Little Ice Age. The nearby Southwestern Pacific, however, experienced warmer-than-average conditions over the course of the Little Ice Age, which is thought to be from the increased trade winds, which increased the evaporation and the salinity in the region. The dramatic temperature differences between the higher latitudes and the equator are thought to have resulted in drier conditions in the subtropics. Independent multiproxy analyses of Raraku Lake (sedimentology, mineralology, organic and inorganic geochemistry, etc.) indicate that
Easter Island Easter Island ( rap, Rapa Nui; es, Isla de Pascua) is an island and special territory of Chile in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian Triangle in Oceania. The island is most famous for its nearl ...
was subject to two phases of arid climate that led to drought. The first occurred between 500 and 1200, and the second occurring during the Little Ice Age from 1570 to 1720. In between both arid phases, the island enjoyed a humid period from 1200 to 1570. That coincided with the peak of the Rapa Nui civilization.


South America

Tree-ring data from Patagonia show cold episodes from 1270 and 1380 and from 1520 to 1670, during the events in the Northern Hemisphere. Eight sediment cores taken from
Puyehue Lake Puyehue Lake (), (Mapudungun: ''puye'', "small fish" and ''hue'', "place") is an Andean piedmont lake on the border of Los Lagos Region with Los Ríos Region of Chile. Puyehue is a lake of glacial origin. Several times during the Pleistocene gl ...
have been interpreted as showing a humid period from 1470 to 1700, which the authors describe as a regional marker of the onset of the Little Ice Age. A 2009 paper details cooler and wetter conditions in southeastern South America between 1550 and 1800 by citing evidence obtained via several proxies and models. 18O records from three Andean ice cores show a cool period from 1600 to 1800. Although it is only anecdotal evidence, the Antonio de Vea expedition entered San Rafael Lake in 1675 through Río Témpanos (Spanish for "Ice Floe River"). The Spanish mentioned no ice floe but stated that the San Rafael Glacier did not reach far into the lagoon. In 1766, another expedition noticed that the glacier reached the lagoon and
calved {{Short pages monitor Scientists have tentatively identified seven possible causes of the Little Ice Age: orbital cycles, decreased solar activity, increased volcanic activity, altered ocean current flows, fluctuations in the human population in different parts of the world causing
reforestation Reforestation (occasionally, reafforestation) is the natural or intentional restocking of existing forests and woodlands ( forestation) that have been depleted, usually through deforestation, but also after clearcutting. Management A de ...
or
deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...
, and the inherent variability of global climate.


Orbital cycles

Orbital forcing Orbital forcing is the effect on climate of slow changes in the tilt of the Earth's axis and shape of the Earth's orbit around the sun (see Milankovitch cycles). These orbital changes modify the total amount of sunlight reaching the Earth by up ...
from cycles in the earth's orbit around the sun has for the past 2,000 years caused a long-term northern hemisphere cooling trend, which continued through the Middle Ages and the Little Ice Age. The rate of
Arctic The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...
cooling is roughly 0.02 °C per century.

That trend could be extrapolated to continue into the future and possibly lead to a full ice age, but the 20th-century instrumental temperature record shows a sudden reversal of that trend, with a rise in global temperatures attributed to
greenhouse gas emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and ...
.


Solar activity

Solar activity includes any disturbances on the Sun such as sunspots and solar flares associated with the variable magnetic field of the solar surface and solar atmosphere (corona). Because
Alfvén's theorem In magnetohydrodynamics, Alfvén's theorem, or the frozen-in flux theorem, "states that in a fluid with infinite electric conductivity, the magnetic field is frozen into the fluid and has to move along with it." Hannes Alfvén put the idea forwar ...
applies, the coronal magnetic field is dragged out into the heliosphere by the solar wind. Irregularities in this heliospheric magnetic field shield Earth from galactic
cosmic ray Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...
s by scattering them, which allows scientists to track solar activity in the past by analyzing both the carbon-14 or beryllium-10 isotopes generated by cosmic rays hitting the atmosphere and which are deposited in terrestrial reservoirs such as tree rings and ice sheets. In the intervals 1400–1550 (the
Spörer Minimum The Spörer Minimum is a hypothesized 90-year span of low solar activity, from about 1460 until 1550, which was identified and named by John A. Eddy in a landmark 1976 paper published in '' Science'' titled '' "The Maunder Minimum"''.Maunder Minimum) there were very low recorded levels of solar activity and they are both within, or at least overlapped with, the LIA for most definitions. However, solar activity deduced from cosmogenic isotopes was as high between the Spörer Minimum and the Maunder Minimum as it was in about 1940, yet this interval is also within the LIA. Hence any relationship between solar activity and the LIA is far from a simple one. A study by Dmitri Mauquoy et al. confirmed that at the beginning of the Spörer Minimum, the carbon-14 production rate rose rapidly. These authors argued this rise coincided with a sharp drop in temperatures deduced from European peat bogs. This temperature drop is also seen in mean northern hemisphere temperatures deduced from a wide variety of paleoclimate indicators but the timing of the onset of the Spörer Minimum is actually some 50 years earlier. A 50-year response lag is possible but is not consistent with subsequent variations in inferred solar activity and average northern hemisphere temperature. For example the peak in solar activity between the Spörer Minimum and the Maunder Minimum is 50 years after the only peak in average northern hemisphere temperature that it could be associated with. A study by Judith Lean in 1999 also pointed to a relationship between the sun and the Little Ice Age. Her research found that there was a 0.13% total solar irradiance (TSI) increase (1.8 Wm^) over 1650–1790 which could have raised the temperature of the earth by 0.3 °C. In the calculated correlation coefficients of the global temperature response to their reconstruction of the solar forcing over three different periods, they found an average coefficient of 0.79 (i.e. 62% of the variation could be explained by the TSI) which indicates a possible relationship between the two components. Lean's team also formulated an equation in which the temperature change is 0.16 °C increase in temperature for every 0.1% increase in total solar irradiance. However, the main problem with quantifying the longer-term trends in TSI lies in the stability of the absolute radiometry measurements made from space, which has improved since the pioneering work of Judith Lean discussed above, but still remains a problem. Analysis comparing trends in modern observations of TSI and cosmic ray fluxes shows that the uncertainties mean that it is possible that TSI was actually higher in the Maunder Minimum than present-day levels, but uncertainties are high with best estimates of the difference between the modern-day TSI and the Maunder-Minimum TSI in the range ±0.5 Wm^ but with a 2\sigma uncertainty range of ±1 Wm^ At the center of the LIA, during the
Spörer Minimum The Spörer Minimum is a hypothesized 90-year span of low solar activity, from about 1460 until 1550, which was identified and named by John A. Eddy in a landmark 1976 paper published in '' Science'' titled '' "The Maunder Minimum"''.Maunder Minimum, sunspots were minimal and cosmogenic isotope deposition (carbon-14 and beryllium-10) was increased in these minima as a result. However, detailed studies from multiple paleoclimate indicators show that the lower Northern Hemisphere temperatures in the Little Ice Age began before the start of the Maunder Minimum but after the start of the Spörer Minimum and persisted until after the Maunder Minimum (and even after the much weaker Dalton Minimum) had ceased. The return to more active solar conditions between these two grand solar minima had no obvious effect on either global or Northern Hemisphere temperatures. The Central England Temperature provide evidence that low solar activity may have contributed to the LIA through the increased occurrence of cold winters, at least in Europe, but colder summers are more correlated with volcanic activity. Numerical climate modelling indicates that volcanic activity was the greater driver of the overall lower temperatures in the little ice age, as seen in a variety of paleoclimate proxies.


Volcanic activity

In a 2012 paper, Miller ''et al.'' link the Little Ice Age to an "unusual 50-year-long episode with four large sulfur-rich explosive eruptions, each with global sulfate loading >60 Tg" and notes that "large changes in solar irradiance are not required." Throughout the Little Ice Age, there was heightened volcanic activity. When a
volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates ...
erupts, its ash reaches high into the atmosphere and can spread to cover the whole earth. The ash cloud blocks out some of the incoming solar radiation, which leads to worldwide cooling for up to two years after an eruption. Also emitted by eruptions is
sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...
in the form of
sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic a ...
. When sulfur dioxide reaches the stratosphere, the gas turns into
sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...
particles, which reflect the sun's rays. That further reduces the amount of radiation reaching the Earth's surface. A recent study found that an especially severe tropical volcanic eruption in 1257, possibly
Mount Samalas Segara Anak is a crater lake in the caldera that formed during the explosive volcanic eruption of Mount Samalas in 1257. The caldera is next to Mount Rinjani on Lombok Island in Indonesia. "Segara Anak" means "child of the sea" and refers to the ...
(pre-caldera edifice of the active Rinjani) near
Mount Rinjani Mount Rinjani ( id, Gunung Rinjani) is an active volcano in Indonesia on the island of Lombok. Administratively the mountain is in the Regency of North Lombok, West Nusa Tenggara (Indonesian: ''Nusa Tenggara Barat'', NTB). It rises to , maki ...
, both in Lombok, Indonesia, followed by three smaller eruptions in 1268, 1275, and 1284, did not allow the climate to recover. That may have caused the initial cooling, and the 1452/1453 mystery eruption triggered a second pulse of cooling. The cold summers can be maintained by sea-ice/ocean feedbacks long after volcanic aerosols are removed. Other volcanoes that erupted during the era and may have contributed to the cooling include Billy Mitchell (c. 1580), Huaynaputina (1600), Mount Parker (1641), Long Island (Papua New Guinea) (ca. 1660), and Laki (1783). The 1815 eruption of Tambora, also in Indonesia, blanketed the atmosphere with ash, and the following year came to be known as the
Year Without a Summer The year 1816 is known as the Year Without a Summer because of severe climate abnormalities that caused average global temperatures to decrease by . Summer temperatures in Europe were the coldest on record between the years of 1766–2000. This ...
, when
frost Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a g ...
and snow were reported in June and July in both
New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...
and Northern Europe.


Ocean circulation

Around 2000s, the slowing of thermohaline circulation was proposed as an explanation. The circulation could have been interrupted by the introduction of a large amount of fresh water into the North Atlantic and might have been caused by a period of warming before the Little Ice Age that is known as the Medieval Warm Period. There is some concern that a
shutdown of thermohaline circulation The Atlantic meridional overturning circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean. It is characterized by a northward fl ...
could happen again as a result of the present warming. More recent research indicates that the overall Atlantic Meriditional Overturning Circulation may already be weaker now than it was during the Little Ice Age,
PDF in UNEP Document Repository
/ref> or perhaps even over the past millennium. While there is still a robust debate about the present-day AMOC strength, these findings make the link between AMOC and the Little Ice Age unlikely. However, some research instead suggests that a far more localized disruption of the North Subpolar Gyre convection was involved in the Little Ice Age. This is potentially relevant for the near future, as a minority of climate models project a permanent collapse of this convection under some scenarios of future
climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
.


Decreased human populations

Some researchers have proposed that human influences on climate began earlier than is normally supposed (see
Early anthropocene The Early Anthropocene Hypothesis (sometimes referred to as 'Early Anthropogenic' or 'Ruddiman Hypothesis') is a stance concerning the beginning of the Anthropocene first proposed by William Ruddiman in 2003. It posits that the Anthropocene, a prop ...
for more details) and that major population declines in Eurasia and the Americas reduced that impact and led to a cooling trend.


The Black Death in Europe

The
Black Death The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Western Eurasia and North Africa from 1346 to 1353. It is the most fatal pandemic recorded in human history, causi ...
is estimated to have killed 30% to 60% of the European population. In total, the plague may have reduced the
world population In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for th ...
from an estimated 475 million to 350–375 million in the 14th century. It took 200 years for the world population to recover to its previous level.
William Ruddiman William F. Ruddiman is a palaeoclimatologist and Professor Emeritus at the University of Virginia. Ruddiman earned an undergraduate degree in geology in 1964 at Williams College, and a Ph.D. in marine geology from Columbia University in 1969. Ru ...
proposed that those large population reductions in Europe, East Asia, and the Middle East caused a decrease in agricultural activity. Ruddiman suggests that
reforestation Reforestation (occasionally, reafforestation) is the natural or intentional restocking of existing forests and woodlands ( forestation) that have been depleted, usually through deforestation, but also after clearcutting. Management A de ...
took place as a result, causing additional carbon dioxide uptake from the atmosphere, leading to the cooling noted during the Little Ice Age.


Mongol invasions

A 2011 study by the Carnegie Institution's Department of Global Ecology asserts that the
Mongol invasions and conquests The Mongol invasions and conquests took place during the 13th and 14th centuries, creating history's largest contiguous empire: the Mongol Empire ( 1206-1368), which by 1300 covered large parts of Eurasia. Historians regard the Mongol devastati ...
, which lasted almost two centuries, contributed to global cooling by depopulating vast regions and replacing cultivated land by carbon-absorbing forest.


Destruction of native populations and biomass of the Americas

William Ruddiman further hypothesized that a reduced population in the Americas after European contact started in the 16th century could have had a similar effect. In a similar vein, Koch and others in 1990 suggested that as European conquest and disease brought by Europeans killed as many as 90% of Indigenous Americans, around 50 million hectares of land may have returned to a wilderness state, causing increased carbon dioxide uptake. Other researchers have supported depopulation in the Americas as a factor and have asserted that humans cleared considerable amounts of forest to support agriculture there before the arrival of Europeans brought on a population collapse. Richard Nevle, Robert Dull and colleagues further suggested not only that anthropogenic forest clearance played a role in reducing the amount of carbon sequestered in Neotropical forests but also that human-set fires played a central role in reducing biomass in Amazonian and Central American forests before the arrival of the Europeans and the concomitant spread of diseases during the
Columbian exchange The Columbian exchange, also known as the Columbian interchange, was the widespread transfer of plants, animals, precious metals, commodities, culture, human populations, technology, diseases, and ideas between the New World (the Americas) in ...
. Dull and Nevle calculated that reforestation in the tropical biomes of the Americas alone from 1500 to 1650 accounted for net
carbon sequestration Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in lan ...
of 2–5 Pg. Brierley conjectured that the European arrival in the Americas caused mass deaths from epidemic disease, which caused much abandonment of farmland. That caused much forest to return, which sequestered more CO2. A study of sediment cores and soil samples further suggests that CO2 uptake via reforestation in the Americas could have contributed to the Little Ice Age. The depopulation is linked to a drop in CO2 levels observed at
Law Dome Law Dome is a large ice dome which rises to directly south of Cape Poinsett, Antarctica. The feature was roughly mapped by the United States Geological Survey from aerial photographs taken by U.S. Navy Operation Highjump, 1946–47, and has been ...
, Antarctica.


Population increases at mid- to high latitudes

It is suggested that during the Little Ice Age, increased deforestation had enough effect on the Earth's
albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refle ...
(reflectiveness) to cause regional and global temperature decreases. Changes in albedo were caused by widespread deforestation at high latitudes, which exposed more snow cover and thus increased reflectiveness of the Earth's surface, as land was cleared for agricultural use. The theory implies that over the course of the Little Ice Age, enough land was cleared to make deforestation a possible cause of climate change. It has been proposed that the Land Use Intensification theory could explain this effect. The theory was originally proposed by Ester Boserup and suggests that agriculture advances only as the population demands it. Furthermore, there is evidence of rapid population and agricultural expansion, which could warrant some of the changes observed in the climate during this period. This theory is still under speculation for multiple reasons: primarily, the difficulty of recreating climate simulations outside of a narrow set of land in those regions; so that one cannot rely on data to explain sweeping changes or to account for the wide variety of other sources of climate change globally. As an extension of the first reason, climate models including this period have shown increases and decreases in temperature globally. That is, climate models have shown deforestation as neither a singular cause for climate change nor a reliable cause for the global temperature decrease.


Inherent variability of climate

Spontaneous fluctuations in global climate might explain the past variability. It is very difficult to know what the true level of variability from internal causes might be given the existence of other forces, as noted above, whose magnitude may not be known. One approach to evaluating internal variability is the use of long integrations of coupled ocean-atmosphere global climate models. They have the advantage that the external forcing is known to be zero, but the disadvantage is that they may not fully reflect reality. The variations may result from chaos-driven changes in the oceans, the atmosphere, or interactions between the two. Two studies have concluded that the demonstrated inherent variability was not great enough to account for the Little Ice Age. The severe winters of 1770 to 1772 in Europe, however, have been attributed to an anomaly in the North Atlantic oscillation.


See also

* * * * * * * * *


References


Further reading

* * * Waldinger, Maria (2022). "The Economic Effects of Long-Term Climate Change: Evidence from the Little Ice Age". ''Journal of Political Economy.'' *


External links


Abrupt Climate Change Information from the Ocean & Climate Change Institute
links to
Woods Hole Oceanographic Institution The Woods Hole Oceanographic Institution (WHOI, acronym pronounced ) is a private, nonprofit research and higher education facility dedicated to the study of marine science and engineering. Established in 1930 in Woods Hole, Massachusetts, i ...
articles * (discussion of Woods Hole research) *
Dansgaard cycles and the Little Ice Age (LIA)
(It is not easy to see a LIA in the graphs.) *
Was El Niño unaffected by the Little Ice Age?
(2002)

c. 2003

updated 2009 * undated review article

(2008)
HistoricalClimatology.com
links, resources, and feature articles on the Little Ice Age and its present-day relevance.
Climate History Network
association of historical climatologists and climate historians, many of whom study the Little Ice Age and its social consequences. {{Authority control 2nd millennium History of climate variability and change Holocene 1930s neologisms Historical eras Volcanic winters