Rebirth for Some, Only Death for Others : Part I

The 14 and 1500’s saw social and religious ferment, economic growth, and dramatic advances in mining, metallurgy, printing, timekeeping, shipbuilding, navigation, and weaponry. Crafts, commerce, and urban life were all revitalized.

A. Karlan

The Renaissance: 1453-1600

The next period of European history is called the Renaissance. Renaissance is a French word that means rebirth. The Renaissance was an age of accelerated change, experimentation, and of great artistic and literary achievements. It was the time of Donatello, Botticelli, Michelangelo, Leonardo daVinci, and Raphael. The Italians in particular tried to recapture the glory of the Roman Empire by refurbishing their cities. It was a time of technological innovations, great discoveries, and intellectual revolutions. There was also a revival of interest in the writings of the ancient Greeks and the Romans. With the fall of Constantinople to the Ottoman Empire, many of the remaining scholars of the Byzantine Empire fled to the West. They reintroduced the Greek tradition of learning and scholarship to the West and this new interest in learning was greatly enhanced by the invention of the printing press.

In 1454, the invention of the Gutenburg press (adapted from a previous Chinese invention and a wine press) began to make books available to the public quickly and cheaply. The classical knowledge of the ancient Greeks and Romans now moved from the domain of the Christian Church to the individual. As scholarship began to develop independently of the Church, the religious biases of the past were questioned. From this came a new way of thinking called humanism, the belief that man controlled his own fate, not God.

Economically this period was a prosperous almost giddy time and one of the reasons was that between 1470 and 1550 there was a slight warming trend in the global climate. The subsistence crisis and the plague had come to an end. It was a time with food to eat and money to spend. Those that survived inherited everything the dead had left behind. Those that took advantage of the new demand for specialty food and fiber became rich and the scarcity of laborers meant high wages. As the standard of living of the peasants rose there was again a demand for goods from abroad. This meant that there was once again money to be made importing luxury goods from the East, especially spices.

Spices played a special role in the culinary, economic and political life of Europe. Europeans were meat eaters by preference, but the supply was seasonal. A shortage of winter fodder made it essential that many cattle be slaughtered in the autumn. The meat soon deteriorated, even when it was preserved by salting. Spices helped to make it palatable; in addition they were reputed to be medicinal, many of them inspiring semi-mystical reverence.

Time Frame, a Time-Life Book Series

In 1453 the Ottoman Empire conquered Constantinople. The fall of Constantinople is generally seen as the end of the Middle Ages and the beginning of the Renaissance. For the Christian Europeans, however, the taking over of the territory of the old Byzantine Empire by the Turkish Muslims meant that the old overland trade routes were essentially cut off. In an attempt to meet the demand for luxury goods and spices, the Portuguese began seeking a new sea route to East. This was made possible by new techniques in shipbuilding, a new means of navigation, the excitement of exploration, and the renewal of tax revenues. As early as 1433, Portuguese sailors had begun exploring the coast of Africa in an attempt to navigate around it to India. In 1488 they reached the tip of Africa opening a sea route to the Orient and the Spice Islands. Then in 1492, a man with a “better idea” attempted to reach the East by sailing west across open ocean instead of around Africa.

The man’s name was Cristoforo Columbus. He based his idea that the best way to get to China was by sailing westward on a rediscovered map of the Greek geographer Ptolomy. Unfortunately his idea hung on a miscalculation which had led Ptolomy to exaggerate the size of the Eurasian landmass. According to Ptolomy the landmass stretched halfway around the world. Based on Ptolomy’s map Columbus figured that the Indies must be less that 2500 miles from the Canary Islands. This was of course wrong but it was about the distance from Spain to the yet unknown (to Europe) continent of North America. Although he did not know it, even at the time of his death, Columbus’s journey west did not discover a new route to India but a whole "New World". And in the process, he had connected this New World with pathogens of the Old World for the first time. The ecological balance of human beings and their infectious diseases was to be disrupted once again.

Next Post :Rebirth for Some, Only Death for Others : Part II

The Mound Builders of Eastern North America

Most Americans are unaware that an American Indian civilization in our Great Plains built one of the largest pyramids anywhere in the world. We all know about the pyramids of Egypt and many of us are aware of the pyramids in Central America, but how many of us have ever even heard about Monk's Mound just outside St. Louis, Missouri? Monk's Mound was a ceremonial temple in the center of a once huge city, called Cahokia .

Cahokia was home to some tens of thousands of inhabitants. It was an important trading and religious center during its peak between 1050 and 1250 AD. Its artisans produced splendid copper ornaments, fine ceramics, and carved statues. Their structures were built of earth, rather than stone, and included defensive structures, sacred enclosures, altars, burial mounds, and temples. Monk's Mound (see the picture below), consisting of four platforms, was the most imposing structure in Cahokia and consisted of 22 million cubic feet of earth. The tallest of its four platforms was 100 feet high. Today, some 70 of the 120 original mounds in Cahokia survive and are maintained by our state park system.

Monks Mound Today

To sustain themselves, the Indians of Cahokia and the surrounding towns depended mainly on growing maize (corn) for food and the hunting of buffalo and antelope. For some 700 years, the Mississippian culture dominated the central and lower Mississippi, lower Ohio and Red River Valleys. At its height, there were hundreds of major towns and thousands of smaller settlements. Cahokia, a complex that covered nearly six square miles, was the largest. To feed such a population required an intensive, well-developed and organized system of agriculture. Yet, sometime around 1250 or 1300 AD, this civilization began to decline.

As with Mycenae, a change in the jet stream may have been the reason why. About 800 years ago, the jet stream changed course and moved further south than usual, bringing a 200-year drought to the northern Great Plains. July is the critical month for rain in that region. Today, the northern Great Plains receives about 25 inches of rain a year and produces good crops of maize and soybean. A drop in rainfall can profoundly affect the final crop yields, and slight shifts in the jet stream can result in rainfalls 25 percent or more below normal. Archaeologists, examining Mississippian sites in Iowa report a significant change in vegetation around 1200 AD to more drought tolerant species and a corresponding decrease in corn production.

Further south in Nebraska, where the jet stream was then passing, the July rainfall was unusually heavy, and the Indian population in this area began to increase. I wonder why? Could it be rainfall for crops… say corn?

Next Post: The Renaissance: Rebirth for Some, Only Death of Others

The Vikings

In the earlier posts about civilization crashes correlated with climate cooling, I made a point to show that when it happens, it has ramifications all over the world. The climate crisises of both 1200 - 800 BC and 150 - 600 AD impacted civilizations all over the world. The crisis of the Little Ice Age did the same thing. First let’s look at the Vikings in Greenland and then the Moundbuilders in North America.

The Vikings - During the High Middle Ages, the Scandinavians became world travelers. The Scandinavians, also called the Norsemen, traveled the rivers of Russia, traded with the Arabs, settled in Greenland, deforested Iceland, and set foot in North America.

The Scandinavian travelers, the Vikings, came across the Arctic Ocean to Iceland and Greenland in the ninth and tenth centuries (The Medieval Warm Period) unimpeded by drift ice and stormy weather. Drift ice is carried by ocean currents and scientists have found that there was a direct relationship between global temperature and ice sighting. Iceland, an island in the North Atlantic Ocean and 750 miles west of Norway, is located at the meeting place of the Arctic water and the Gulf Stream. In cold times the Arctic water carries the ice south. In warmer times the Gulf Stream dominates the area and the ice is kept away. The Greenlander's Sagas, early Icelandic prose narratives of the exploits of Lief Ericson and his son Eric the Red, do not mention drift ice until the 13th century. Over 100,000 people made the journey to settle in Iceland. No icebergs or severe winter storms impeded the ships bringing colonists or supplies from the mainland. The warmth of the climate allowed settlers in Greenland to grow vegetables and hay for their livestock. Today the Greenland homestead of Eric the Red is barren tundra (polar zone).

Around 1350, the drift ice and bad winter storms were making the voyages to Greenland and Iceland more difficult and more expensive. Eventually the voyages stopped altogether. Deforestation, overgrazing, and soil erosion reduced the inhabitants' ability to sustain themselves. The colder climate compounded their problems by shortening their growing season. Spring and fall temperatures determine the length of the growing season and a small drop in temperature can shorten the growing season by several weeks. This is enough to make the difference between having a good harvest and not having one. While grain was grown in most of Iceland during the early years only barley, a short season grain, could be grown after 1300. By 1450 all the settlers had perished. The Vikings that first settled Iceland were tall, averaging 5'7" in height. In their last years, according to a commission sent from Denmark to find the remains of the early settlers, they were "crippled, dwarf like, twisted and diseased" and less than five feet tall. Excavation of their graves indicated that they still wore European clothing and ate European food. They did not adopt the ways of the Indians that survived this change in the climate.

They failed to change their cultural ways and perished. Are we smart enough not to do the same?

The evidence suggests that during thirteenth and fourteenth centuries the jet stream shifted to the south bringing the cold Arctic air with it. Sailing records also suggest that the gulf steam moved south and both movements correlate with the increased volcanic activity in 1250-1500. This was a time of climate change for all the civilizations under the influence of the northern jet stream. The vineyards in England froze, alpine glaciers advanced across farmland in Norway, and the colonists in Iceland and Greenland starved. The climate change brought floods to China and, as we have already seen, wet weather to all of southern Europe with equally disastrous consequences, and drought stuck North America.

Next Post: The Mound Builders of Eastern North America

Other Casualties of the Black Death

The deaths of between one fourth and one third of the Old World’s people were not the only casualties of the Black Death. Another casualty was the fate of European Jews. For example, in Spain there was a large and successful Jewish population. These Jews were treated better than anywhere else in Christian Europe and they had prospered by serving as tax collectors, physicians, pharmacists, and estate managers. With the coming of the Black Death this tolerance came to an end and an era of “virulent anti-Semitism” began. By the time the plague had run its course in Southern Europe, whole communities of Spanish Jews no longer existed. In Germany it was much worse.

...the Jews were suddenly and violently charged with infecting the well and water, and corrupting the air. The whole world rose up against them cruelly on this account. In Germany... they were massacred and slaughtered by Christians, and many thousands were burned everywhere, indiscriminately.

Jean de Venette

In Switzerland, Jews were expelled, burned, and massacred. The violence against the Jews in Europe waned as the plague waned but by 1351, 60 major and 159 smaller Jewish communities were extinct, over 350 massacres had taken place, and the many of the remaining Jews immigrated to Eastern Europe, into Poland and Russia.

The psychological terror of the plague’s devastation not only led to scape-goating but it also left many of the survivors with a lost faith in themselves and in their institutions. The optimism of the High Middle Ages was replaced by pessimism. Art and literature reflected the gloom and doom of the time.

..the gay light, individualistic themes (in art) begun in the thirteenth century (1200’s)... were replaced by a new conservatism and moralizing tone brought by the Black Death.

Generally...themes of youth, exuberance, happiness and joy were played down. The dance of death became a common literary motif. Mystery plays with religious themes also became common, and they usually told of human decay and the torments of hell. There was much written about the ages of life mostly in the form of calendars, with analogies to the seasons of the year. In the thirteenth and early fourteenth centuries (1200-1330’s), the calendars emphasized spring and summer; in the late fourteenth and fifteenth centuries (1350-1500), they turned to themes of autumn and winter.

R. S. Gottfried

The faith in the clergy of both the Islamic and Christian religions, the very foundation of Middle Age society, was weakened by their response to the plague. Muslim clerics rejected the idea that the plague was a contagious disease transmitted from person to person and told their faithful not to flee. Instead the faithful were told it was God that disseminated the disease and they should stay and accept Allah’s will. This martyrdom did not sit well with many of the faithful. Other Muslim leaders told their followers that the plague was punishment for wrong-doing and that true believers would not be harmed. This, as many true believers found out, was not true.

Christians, on the other hand, listened to their physicians, who were trained and licensed by the Church. Unfortunately the advice these learned men of the cloth gave on how to avoid the plague proved useless. In addition, many of the parish priests fled leaving no one to comfort the sick or deliver the last rites to those that died. When the plague subsided, the Church no longer had as powerful a hold on its subjects as it had before the outbreak of the plague. While most still believed in the teachings of the Church, they questioned whether the clergy were necessary to attain salvation. Many post-plague Christians felt they could communicate with God through a saint or directly themselves without the intervention of the clergy. Years of famine and pestilence had changed the attitude of the people from one of dependence to one of individualism and self-reliance.

Older ineffective methods and traditional authorities were cast away.

R. S. Gottfried

Dissatisfaction with the clergy, coupled with depopulation, also began to pull apart the social order of medieval society. Before the subsistence crisis and the return of the plague, medieval society was theoretically divided into three classes. The first class was the clergy. Their role was to obtain divine grace for all through prayer and good works. Because they were well educated, they also served as the society’s clerks and bureaucrats (this lead to corruption that added to the dissatisfaction over their inability to deal with the plague). The second class was the local king, the nobles, and military elite. The first and second classes owned the land. The third class was the agricultural workers, the peasants or serfs. In return for a place to live and the protection of the military, the serfs tilled the soil of the elite and grew the crops. In time this class also included the workers and merchants in the towns. These were the taxpayers of the society. (Sound familiar?) This societal structure is called feudalism.

When the plague ended, the first class, seen as corrupt and not to be doing their jobs, was discredited. The depopulation of Europe, which continued until the 1500’s due to recurrences of the plague and other infectious diseases, ended Europe’s subsistence crisis and turned the economics of the feudal system on its head. Before the plague the land-owners and hunger held complete control over the serfs. After the plague, food prices plummeted and there was shortage of labor. Land-owners had to hire wage laborers to farm their land. These laborers demanded higher wages and better food. They got both. The living standards of the third class rose while the income of the aristocracy fell (20 % between 1337 and 1353).

For the peasants who farmed the land, depopulation, providing they survived the plague, was a great boon. Yet for those who held the land as lords -- the aristocracy and the clergy-- it was disastrous. ... Land was no longer as valuable has it had been, but the laborers were worth much more than before. ... High wages and low prices were ruining the lords, while members of the third order (class) were embarking on 150 years of comparative prosperity.

R. S. Gottfried

When the aristocracy tried to reinstate the old order though legislation, there was a series of peasant revolts between 1358 and 1381. These revolts reflected the sharp conflicts between the classes that developed after the plague as the ruling classes attempted to deny the lower class the better fortune depopulation had brought.

The labor shortage also brought a boom in the slave trade. The Black Death depopulated the areas that were the traditional source of European slaves. Italian slave traders looked to new areas from which to obtain slaves. One place they looked was the plague-free Sahara Dessert of Africa. The slavery of Africans was also a casualty of the Black Death, a casualty that would have future ramifications in a place soon to be rediscovered, the New World.

Let’s check out what happened to those rediscovers – the Vikings. (The American Indians found it first! )

Next Post: The Vikings

By the way: One thing that was not a casualty of the depopulation of the Old World was the environment of Europe. Depopulation had a positive effect on the land. Fields lay fallow because the villagers that once farmed them were either dead or had fled. Forests and pasture-land were restored and over-cropping ended. The raising of animals was once again profitable and agriculture diversified. Instead of a monoculture of wheat, farmers began to grow grapes for wine, sugar and fruits, oats to feed livestock, barley to make ale and beer, and crops of hemp and flax for the one of the new industries of the time, the textile industry (underpants were all the rage). By the early 1400’s, the soil exhaustion of the 1300’s came to an end and yields began to rise.

Take home message ?....

Overpopulation which leads to environmental degradation is also an important factor affecting the ability of humans to feed themselves via agriculture. Climate change is very important but when it is compounded by overpopulation and environmental degradation, civilizations are in really big trouble. This is because the carrying capacity of the environment decreases even more – the ability of a civilization to feed itself diminishes.

The Rats, the Flea and the Weather

Although the human flea can transmit Y. pestis, this flea is not the normal vector of this disease in humans. The most common vector is a flea that infests rats and this flea normally prefers rats to any other host. This means that the flea does not usually feed on a human host. So the environmental conditions that can lead to an epidemic of the bubonic plague in humans must also include some reason that forces the rat flea to bite humans. That condition is an increased death rate death in the population of rats. The flea only moves to a non-rat host when the population of rats decreases drastically.

One thing that can kill large numbers of rats is the bubonic plague itself. Rats can tolerate a modest population of the pathogen in their blood stream, but if it invades the lungs or the brain of the rat, this disease becomes lethal to rats (it also kills many domestic animals). Thus an epidemic of the bubonic plague among the rat population of a city can lead to epidemic among the human population of the city and their domestic animals.

Other circumstances can also cause massive die off of rats. For example, in 1994 an outbreak of the plague in Surat India was preceded by massive flooding. The floods drowned many of the city’s rats.

In addition, the climate can influence the severity of the disease. The likelihood of a flea’s bite transmitting the pathogen increases when the temperature is between 20 and 25 degrees C. At this temperature the bacilli multiply in the flea’s stomach in numbers large enough to cause a blockage and threaten the flea with starvation. This causes the flea to try to clear the blockage by regurgitation. If the temperature rises above 27 degrees C, the blockage in the flea’s gut dissolves. Also the larvae of the flea will die if the humidity is too low. Thus a cool, moist climate is the optimum for both the survival of the flea and transmission of the disease. And this was exacerbated by the Fusarium toxins in the food the people of Europe were eating during the Middle Ages.

Today, in the age of vaccines and informed physicians, we lack experience with epidemic diseases and both the general public and modern historians tend to underestimate the full force a new infection can have on a population. Thus we all overlook the role diseases have played in the course of history. We are even less aware of how plant diseases can influence the affairs of humans. Yet both have and will continue to significantly influence human health. And both are influenced by the weather, which, as I am trying to get across, is influenced by the global climate of the time!

“Biology and medicine prove to be crucial driving forces in human history…” Jared Diamond

Next Post: Other Casualties of the Black Death

And There is Even More to it Than That!

If the change in global temperature brings more rain to an area than it is used to, as happened in Western Europe during the Middle Ages, then it also means plant disease can increase and that in turn can increase the devastation caused by human disease. For example, during the Late Middle Ages, a postharvest disease caused by a fungus called Fusarium is believed to have increased the deaths caused by the bubonic plague in areas with increased rain.

Generally this fungus contaminates the seeds either before they are harvested or at the time of harvest. This fungus then grows within the seed during storage. For this fungus to continue to grow it requires a high moisture content in the seeds. Today most grain is stored at a moisture content of 12-14% which is too low for the fungi to grow and the fungi die after a few months in storage and do not infect other seeds. However during the Late Middle Ages, the people had neither the technology nor the knowledge to store grain at this moisture content. During the 13 and 1400’s the moisture content of harvested grain was at the mercy of the weather. Because the weather was moist during this time the moisture content in the seeds must have been high. The fungi in contaminated seed would have continued to grow under these conditions and would have infected other seeds.

As the fungus grows within a seed it not only causes decay of the seed but it also produces substances called mycotoxins. The ingestion of moldy grain containing these toxins can lead to a disease whose symptoms include necrosis of the skin, hemorrhage, liver and kidney damage, and death. Fusarium molds produce a number of mycotoxins. These toxins in both lethal and sublethal doses not only cause the above symptoms but they can also cause an immune deficiency. The toxins attack the lymphoid cells critical for the body’s defense against infection.

According to Mary Kilbourne Matossian in her book Poisons of the Past, the highest moralities of the plague during the late Middle Ages occurred in areas where surplus grain was stored (thus there would also be a surplus of rats) and with the incidence of high humidity, rain, and flooding.

“For two years prior to the pandemic of 1348 in Europe the weather was extraordinary rainy and humid and crops were poor. The summer of 1348 was exceptionally wet in England, where the plague began its ravage; on the other hand it was not so wet in Scotland that year and the plague did not spread widely there until the wet summer of 1350.

The coldest and driest regions were untouched by plaque during the pandemic. Iceland, northern Norway and Sweden, Finland and large areas of Russia and the Balkans escaped the blight. So did the mountainous and desert areas of the Near East.”

Mary K. Matossian

Knowing that toxin producing fungi like Fusarium flourish in moist conditions, Matossian speculates that the ingestion of moldy grain by the rats markedly increased the mortality of rats thus increasing the likelihood that the rat flea would move to other animals including humans. (The mortality of horses, cattle, sheep and goats was exceptionally high during the wet period between 1345 and 1350). In addition, the humans were eating bread made with the moldy toxin-infested grain. The ingestion of mycotoxins would have compromised their immune system making them more likely to die when exposed to the plague pathogen. Thus, the increased mortality rates in some places most likely can be explained by a combination of the virulence of Yersinia pesti, the bacteria that causes disease known as the Black Death, and immune deficiencies caused by mycotoxin food-poisoning in both rats and humans

“Man does not live by bread alone - but he must have bread. And he must have bread that is truly the staff of life, not a scepter of death.”

Mary K. Matossian

Next Post: The Rats, the Flea and the Weather

After the Fall of Rome

The first civilizations (Sumeria, Eygpt, Myceanea etc.) were more or less isolated from each other. With the second rise of civilization in Europe and Asia (i.e. the Roman Empire and the Han Dynasty in China) things get a bit more complicated. This was because the world’s population centers were no longer isolated from each other. That meant something new – the movement of human diseases.

Routine travel by sailing ships and by caravan across the length and breadth of the Old World began to reach its peak organization between 100 and 200 CE. During this time thousands of people began to travel the trade routes established between the four centers of civilization, from China through India and the Middle East to the Mediterranean and back. And with them came disease, human disease.

According to William McNeil in his book Plagues and Peoples, between 150 and 600 AD, “new” infectious diseases attacked the people of both China and Rome. These diseases killed millions of people and the social impact of this heavy death toll was devastating. One of those diseases was Bubonic Plague. This disease is believed to have been a part of the demise of the Roman Empire but in the 1300’s it hit Europe with a vengeance.

Let’s take another look at the climate over the last 6000 years (graph above). Look at the temperatures after Rome declines. There is a small dip in the global temperature. That was enough to bring down Rome and plunge the European world into a second Dark Age, or the Early Middle Ages.

The temperature rises again to where it was before Rome declined. This is time period historians call the High Middle Ages. It is also called the Medieval Warm Period. This was a good time in Europe. During this period populations increased in Europe and wheat grew well all the way north into Scandinavia.

Then the global temperature falls again during a time called the Late Middle Ages. This is the beginning of what scientists call The Little Ice Age.

“Around 1300, centuries of European prosperity and growth came to a halt. A series of famines and plagues, such as the Great Famine of 1315–1317 and the Black Death, reduced the population by as much as half according to some estimates. Along with depopulation came social unrest and endemic warfare.”

The Little Ice Age Temperature Graph

The temperature rises slightly again (see graph above) and we have the Renaissance, another good time in Western Europe and then Europe gets hit again with cold temperatures, the coldest period of the time called the Little Ice Age.

In his book, "The Little Ice Age: How Climate Made History, 1300–1850", anthropology professor Brian Fagan of the University of California at Santa Barbara, tells of the plight of European peasants during the 1300 to 1850 chill: famines, hypothermia, bread riots, and the rise of despotic leaders brutalizing an increasingly dispirited peasantry. "In the late 17th century," writes Fagan, "agriculture had dropped off so dramatically that Alpine villagers lived on bread made from ground nutshells mixed with barley and oat flour. Finland lost perhaps a third of its population to starvation and disease.”

Can you see a pattern here? When the weather is good for farming, populations grow and prosper. When weather for is bad for farming, populations decrease because of starvation, disease, and warfare.

Next Post: And There is Even More to it Than That!