With planetary geometry matching the Late Antique Little lce age (LALIA) and hundreds of solar scientists now 100% certain that we are heading in to a grand solar minimum starting now, we should be looking at the effects of the mid 6th century as clues of what to expect starting now and plan accordingly.
By analysing tree-ring data for the past 2,000 years in Europe and Asia, scientists from the Swiss Federal Institute for Forest, Snow and Landscape Research WSL were able to precisely reconstruct the summer temperature for each year.
Scientists can analyse tree-ring widths in old trees to accurately predict temperatures.
By looking at these, they found that during the 6th century there was a drop in temperature of an average of three degrees celsius.
Ulf Büntgen, lead researcher on the project, said: "This was the most dramatic cooling in the Northern Hemisphere in the past 2,000 years.”
They believe that this climate change was triggered by three volcanic eruptions in 536, 540 and 547CE.
The team has dubbed this period the Late Antique Little Ice Age (LALLI).
This, they add, contributed to disease and famine to spread across the world.
They highlight the Justinian plague arose between 541 and 543CE which took the lives of millions of people over the ensuing centuries and contributed to the collapse of the Eastern Roman Empire.
This cooler period also allowed the Arab Empire to bloom in the Middle East as the Arabian Peninsula received more rain, meaning that more vegetation could grow which afforded them a larger army.
Additionally, more people migrated East towards China to escape famine and disease causing dramatic social shifts in Asia too.
Tensions rose between nomadic groups and the Chinese natives which caused the natives to form an allegiance with the Eastern Romans, which led to the conquering of Persia.
The knock-on effect caused by climate change in ancient times will give us a better idea of how to deal with modern day global warming, the researchers write in Nature Geoscience.
Professor Büntgen said: "We can learn something from the speed and scale of the transformations that took place at that time.”
A later “Little Ice Age” between 14th and 19th centuries has been well documented and linked to political upheavals and plague pandemics in Europe, but the new study is the first to provide a comprehensive climate analysis across both Central Asia and Europe during this earlier period.
“With so many variables, we must remain cautious about environmental cause and political effect, but it is striking how closely this climate change aligns with major upheavals across several regions,” added Büntgen.
The multidisciplinary research team made up of climatologists, naturalists, historians and linguists mapped the new climate information against a particularly turbulent period in history in Europe and central Asia. The volcanic eruptions probably affected food supplies – a major famine struck the region at precisely this time followed immediately by the pandemic.
Further south, the Arabian Peninsula received more rain allowing more vegetation to grow. The researchers speculate this may have driven expansion of the Arab Empire in the Middle East because the vegetation would have sustained larger herds of camels used by the Arab armies for their campaigns.
In cooler areas, several tribes migrated east towards China, possibly driven away by a lack of pastureland in central Asia. This led to hostilities between nomadic groups and the local ruling powers in the steppe regions of northern China. An alliance between these steppe populations and the Eastern Romans brought down the Sasanian Empire in Persia, the final empire in the region before the rise of the Arab Empire.
The researchers write, “The Late Antique Little Ice Age fits in well with the main transformative events that occurred in Eurasia during that time.”
Large volcanic eruptions can affect global temperature for decades. The researchers suggest that the spate of eruptions combined with a solar minimum, and ocean and sea-ice responses to the effects of the volcanoes, extended the grip of the freezing climate for over a century.
Büntgen points out that their study serves as an example of how sudden climatological shifts can change existing political systems. “We can learn something from the speed and scale of the transformations that took place at that time,” he said.
The temperature reconstruction, based on new tree-ring measurements from the Altai mountains where Russia, China, Mongolia and Kazakhstan meet, corresponds remarkably well with temperatures in the Alps in the last two millennia. The width of tree rings is a reliable way to estimate summer temperatures.
The research is part of the Euro-Med2k working group of the international Past Global Changes (PAGES) project. Last week, (29 January 2016) members of the group published a comprehensive analysis of summer temperatures in Europe in the last 2000 years, concluding that current summer temperatures are unprecedented during this period. The Euro-Med2k Working Group reconstructs and models past climate in the Europe and Mediterranean regions (including southern Europe, the Middle East and northern Africa) over the last 2,000 years. PAGES is part of Future Earth – a major international research program to study global sustainability.
Extreme weather events of 535–536The extreme weather events of 535–536 were the most severe and protracted short-term episodes of cooling in the Northern Hemisphere in the last 2000 years. The event is thought to have been caused by an extensive atmospheric dust veil, possibly resulting from a large volcanic eruption in the tropics, or debris from space impacting the Earth.Its effects were widespread, causing unseasonal weather, crop failures and famines worldwide.
Documentary evidenceThe Byzantine historian Procopius recorded of 536, in his report on the wars with the Vandals, "during this year a most dread portent took place. For the sun gave forth its light without brightness... and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear". The Gaelic Irish Annals record the following:
- "A failure of bread in the year 536 AD" – the Annals of Ulster
- "A failure of bread from the years 536–539 AD" – the Annals of Inisfallen
- Low temperatures, even snow during the summer (snow reportedly fell in August in China, which caused the harvest there to be delayed)
- Crop failures
- "A dense, dry fog" in the Middle East (with regular sandstorm) , China and Europe
- Drought in Peru, which affected the Moche culture.
Scientific evidenceTree ring analysis by dendrochronologist Mike Baillie, of the Queen's University of Belfast, shows abnormally little growth in Irish oak in 536 and another sharp drop in 542, after a partial recovery. Similar patterns are recorded in tree rings from Sweden and Finland, in California's Sierra Nevada and in rings from Chilean Fitzroya trees. Ice cores from Greenland and Antarctica show evidence of substantial sulfate deposits in around 533–534 ± 2, which is evidence of an extensive acidic dust veil.
Possible explanationsIt has been conjectured that the changes were due to ashes or dust thrown into the air after the eruption of a volcano (a phenomenon known as "volcanic winter"), or after the impact of a comet or meteorite. The evidence of sulfate deposits in ice cores strongly supports the volcano hypothesis; the sulfate spike is even more intense than what accompanied the lesser episode of climatic aberration in 1816, popularly known as the "Year Without a Summer", which has been connected to the explosion of the volcano Mount Tambora in Sumbawa. In 1984, R. B. Stothers postulated that the event might have been caused by the volcano Rabaul in what is now New Britain, near Papua New Guinea. In 1999, David Keys in his book Catastrophe: A Quest for the Origins of the Modern World (supported by work of the American volcanologist Ken Wohletz), suggested that the volcano Krakatoa exploded at the time and caused the changes. It is suggested that an eruption of Krakatoa described as occurring in 416 by the Javanese Book of Kingsactually took place in 535–536, there being no other evidence of such an eruption in 416. In 2009, Dallas Abbott of Columbia University's Lamont–Doherty Earth Observatory in New York published evidence from Greenland ice cores that multiple comet impacts caused the haze. The spherules found in the ice may originate from terrestrial debris ejected into the atmosphere by an impact event. In 2010, Robert Dull, John Southon and colleagues presented evidence suggesting a link between the Tierra Blanca Joven (TBJ) eruption of the Ilopango caldera in central El Salvador and the 536 event. Although earlier published radiocarbon evidence suggested a two-sigma age range of 408–536, which is consistent with the global climate downturn, the connection between 536 and Ilopango was not explicitly made until research on Central American Pacific margin marine sediment cores by Steffen Kutterolf and colleagues showed that the phreatoplinian TBJ eruption was much larger than previously thought. The radioactive carbon-14 in successive growth increments of a single tree that had been killed by a TBJ pyroclastic flow was measured in detail using accelerator mass spectrometry; the results supported the date of 535 as the year in which the tree died. A conservative bulk tephra volume for the TBJ event of ~84 km3 was calculated, indicating a large Volcanic explosivity index 6+ event and a magnitude of 6.9. The results suggest that the Ilopango TBJ eruption size, latitude and age are consistent with the ice core sulphate records of Larsen et al. 2008. A 2015 study further supported the theory of a major eruption in "535 or early 536", with North American volcanoes considered a likely candidate. It also identified signals of a second eruption in 539-40, likely to have been in the tropics, which would have sustained the cooling effects of the first eruption through to around 550.
DescriptionThe Year Without a Summer was an agricultural disaster. Historian John D. Post has called this "the last great subsistence crisis in the Western world". The unusual climatic aberrations of 1816 had the greatest effect on most of New England, Atlantic Canada, and parts of western Europe. Typically, the late spring and summer of central and northern New England and southeastern Canada are relatively stable: temperatures (average of both day and night) average between about 20 and 25 °C (68 and 77 °F) and rarely fall below 5 °C (41 °F).
North AmericaIn the spring and summer of 1816, a persistent "dry fog" was observed in parts of the eastern U.S. The fog reddened and dimmed the sunlight, such that sunspots were visible to the naked eye. Neither wind nor rainfall dispersed the "fog". It has been characterized as a "stratospheric sulfate aerosol veil". At higher elevations, where farming was problematic in good years, the cooler climate did not quite support agriculture. In May 1816, frost killed off most crops in the higher elevations of Massachusetts, New Hampshire, and Vermont as well as upstate New York. On June 6, snow fell in Albany, New York, and Dennysville, Maine. Many commented on the phenomenon. Sarah Snell Bryant, of Cummington, Massachusetts, wrote in her diary, "Weather backward." At the Church Family of Shakers in upstate New York, near New Lebanon, Nicholas Bennet wrote in May 1816, "all was froze" and the hills were "barren like winter". Temperatures went below freezing almost every day in May. The ground froze solid on June 9. On June 12, the Shakers had to replant crops destroyed by the cold. On July 7, it was so cold, everything had stopped growing. The Berkshire Hills had frost again on August 23, as did much of the upper northeast. A Massachusetts historian summed up the disaster:
Severe frosts occurred every month; June 7th and 8th snow fell, and it was so cold that crops were cut down, even freezing the roots .... In the early Autumn when corn was in the milk it was so thoroughly frozen that it never ripened and was scarcely worth harvesting. Breadstuffs were scarce and prices high and the poorer class of people were often in straits for want of food. It must be remembered that the granaries of the great west had not then been opened to us by railroad communication, and people were obliged to rely upon their own resources or upon others in their immediate locality.In Cape May, New Jersey, frost was reported five nights in a row in late June, causing extensive crop damage. In July and August, lake and river ice was observed as far south as northwestern Pennsylvania. Frost was reported as far south as Virginia on August 20 and 21. Rapid, dramatic temperature swings were common, with temperatures sometimes reverting from normal or above-normal summer temperatures as high as 95 °F (35 °C) to near-freezing within hours. The weather was not in itself a hardship for those accustomed to long winters. The real problem lay in the weather's effect on crops and thus on the supply of food and firewood. Thomas Jefferson, retired from the presidency and farming at Monticello in Virginia, sustained crop failures that sent him further into debt. On September 13, a Virginia newspaper reported that corn crops would be one half to two-thirds short, and lamented that "the cold as well as the drought has nipt the buds of hope". A Norfolk, Virginia Newspaper complained:
It is now the middle of July, and we have not yet had what could properly be called summer. Easterly winds have prevailed for nearly three months past... the sun during that time has generally been obscured and the sky overcast with clouds; the air has been damp and uncomfortable, and frequently so chilling as to render the fireside a desirable retreat.Regional farmers did succeed in bringing some crops to maturity, but corn and other grain prices rose dramatically. The price of oats, for example, rose from 12¢ a bushel($3.40/m³) in 1815 (equal to $1.55 today) to 92¢ a bushel ($26/m³) in 1816 ($12.85 today). Crop failures were aggravated by an inadequate transportation network: with few roads or navigable inland waterways and no railroads it was expensive to import food.
EuropeCool temperatures and heavy rains resulted in failed harvests in Britain and Ireland. Families in Wales travelled long distances as refugees, begging for food. Famine was prevalent in north and southwest Ireland, following the failure of wheat, oats, and potato harvests. In Germany, the crisis was severe; food prices rose sharply. With the cause of the problems unknown, people demonstrated in front of grain markets and bakeries, and later riots, arson, and looting took place in many European cities. It was the worst famineof 19th-century Europe. The effects were widespread and lasted beyond the winter. In western Switzerland, the summers of 1816 and 1817 were so cool that an ice dam formed below a tongue of the Giétro Glacier high in the Val de Bagnes. Despite engineer Ignaz Venetz's efforts to drain the growing lake, the ice dam collapsed catastrophically in June 1818.
AsiaIn China, the cold weather killed trees, rice crops, and even water buffalo, especially in the north. Floods destroyed many remaining crops. Mount Tambora's eruption disrupted China's monsoon season, resulting in overwhelming floods in the Yangtze Valley. In India, the delayed summer monsoon caused late torrential rains that aggravated the spread of cholera from a region near the River Ganges in Bengal to as far as Moscow.
CausesThe aberrations are now generally thought to have occurred because of the April 5–15, 1815, Mount Tambora volcanic eruption on the island of Sumbawa, Indonesia (then part of the Dutch East Indies, but under French rule during Napoleon's occupation of the Netherlands), described by Thomas Stamford Raffles. The eruption had a volcanic explosivity index (VEI) ranking of 7, a colossal event that ejected at least 100 km3 (24 cu mi) of material. It was the world's largest eruption since the Hatepe eruption in 180 AD. Other large volcanic eruptions (with VEIs at least 4) around this time were:
- 1812, La Soufrière on Saint Vincent in the Caribbean
- 1812, Awu in the Sangihe Islands, Dutch East Indies
- 1813, Suwanosejima in the Ryukyu Islands, Japan
- 1814, Mayon in the Philippines
EffectsAs a result of the series of volcanic eruptions, crops in the aforementioned areas had been poor for several years; the final blow came in 1815 with the eruption of Tambora. Europe, still recuperating from the Napoleonic Wars, suffered from food shortages. Food riots broke out in the United Kingdom and France, and grain warehouses were looted. The violence was worst in landlocked Switzerland, where famine caused the government to declare a national emergency. Huge storms and abnormal rainfall with flooding of Europe's major rivers (including the Rhine) are attributed to the event, as is the August frost. A major typhus epidemic occurred in Ireland between 1816 and 1819, precipitated by the famine caused by the Year Without a Summer. An estimated 100,000 Irish perished during this period. A BBC documentary, using figures compiled in Switzerland, estimated that the fatality rates in 1816 were twice that of average years, giving an approximate European fatality total of 200,000 deaths. New England also experienced major consequences from the eruption of Tambora. The corn crop was significantly advanced in New England and the eruption caused the crop to fail. In the summer of 1816, corn was reported to have ripened so badly that no more than a quarter of it was usable for food. The crop failures in New England, Canada, and parts of Europe also caused the price of wheat, grains, meat, vegetables, butter, milk, and flour to rise sharply. The eruption of Tambora also caused Hungary to experience brown snow. Italy's northern and north-central region experienced something similar, with red snow falling throughout the year. The cause of this is believed to have been volcanic ash in the atmosphere. In China, unusually low temperatures in summer and fall devastated rice production in Yunnan, resulting in widespread famine. Fort Shuangcheng, now in Heilongjiang, reported fields disrupted by frost and conscripts deserting as a result. Summer snowfall or otherwise mixed precipitation was reported in various locations in Jiangxi and Anhui, located at around 30°N. In Taiwan, which has a tropical climate, snow was reported in Hsinchu and Miaoli, and frost was reported in Changhua.
Cultural effectstephra in the atmosphere led to unusually spectacular sunsets during this period, a feature celebrated in the paintings of J. M. W. Turner. This may have given rise to the yellow tinge predominant in his paintings such as Chichester Canal circa 1828. Similar phenomena were observed after the 1883 eruption of Krakatoa, and on the West Coast of the United States following the 1991 eruption of Mount Pinatubo in the Philippines. The lack of oats to feed horses may have inspired the German inventor Karl Drais to research new ways of horseless transportation, which led to the invention of the draisine or velocipede. This was the ancestor of the modern bicycle and a step toward mechanized personal transport. The crop failures of the "Year without a Summer" may have helped shape the settling of the "American Heartland", as many thousands of people (particularly farm families who were wiped out by the event) left New England for what is now western and central New York and the Midwest (then the Northwest Territory) in search of a more hospitable climate, richer soil, and better growing conditions. Indianabecame a state in December of 1816 and Illinois two years later. British historian Lawrence Goldman has suggested that this migration into the Burned-over district of New York was responsible for the centering of the anti-slavery movement in that region. Vermont alone experienced a decrease in population of between 10,000 and 15,000, erasing seven previous years of population growth. Among those who left Vermont were the family of Joseph Smith, who moved from Norwich, Vermont (though he was born in Sharon, Vermont) to Palmyra, New York. This move precipitated the series of events that culminated in the publication of the Book of Mormon and the founding of the Church of Jesus Christ of Latter-day Saints. In June 1816, "incessant rainfall" during that "wet, ungenial summer" forced Mary Shelley, John William Polidori, and their friends to stay indoors at Villa Diodati overlooking Lake Geneva for much of their Swiss holiday. They decided to have a contest to see who could write the scariest story, leading Shelley to write Frankenstein, or The Modern Prometheus and Lord Byron to write "A Fragment", which Polidori later used as inspiration for The Vampyre — a precursor to Dracula. In addition, Lord Byron was inspired to write the poem "Darkness", by a single day when "the fowls all went to roost at noon and candles had to be lit as at midnight". Justus von Liebig, a chemist who had experienced the famine as a child in Darmstadt, later studied plant nutrition and introduced mineral fertilizers.
- Toba catastrophe 70,000 to 75,000 years ago
- The 1628–26 BCE climate disturbances, usually attributed to the Minoan eruption of Santorini
- The Hekla 3 eruption of about 1200 BCE, contemporary with the historical Bronze Age collapse
- The Hatepe eruption (sometimes referred to as the Taupo eruption), around 180 CE
- Extreme weather events of 535–536 have been linked to the effects of a volcanic eruption, possibly at Krakatoa, or Ilopango in El Salvador.
- The Heaven Lake eruption of Paektu Mountain between North Korea and the People's Republic of China, in 969 (± 20 years), is thought to have had a role in the downfall of Balhae.
- The 1257 Samalas eruption of Mount Rinjani on the island of Lombok in 1257
- An eruption of Kuwae, a Pacific volcano, has been implicated in events surrounding the Fall of Constantinople in 1453.
- An eruption of Huaynaputina, in Peru, caused 1601 to be the coldest year in the Northern Hemisphere for six centuries (see Russian famine of 1601–1603); 1601 consisted of a bitterly cold winter, a cold, frosty, late (possibly nonexistent) spring, and a cool, wet summer.
- An eruption of Laki, in Iceland, caused thousands of fatalities in Europe, 1783–84.
- The eruption of Mount Pinatubo in 1991 led to odd weather patterns and temporary cooling in the United States, particularly in the Midwest and parts of the Northeast. An unusually mild winter was followed by an unusually cool, wet summer and a cold, early autumn in 1992. Enhanced rainfall occurred across the West Coast of the United States, particularly California, during the 1991–92 and 1992–93 rainy seasons.