16.2 Famine, Climate Change, and Migration

The Effects of Climate Change in the Fourteenth Century

Perhaps the greatest challenge in grasping the impact of climate change on the past is the limitations of traditional historical sources. Texts and other written source materials often provide scant information about environmental fluctuations of earlier centuries. To overcome these barriers, the field of historical climatology focuses on reconstructing and analyzing climates of the past and comparing them with modern conditions, allowing scholars to expand the traditional source base of historical research. Historians study references to crop yields and weather fluctuations in weather journals and tax records, along with scientific data drawn from tree rings and organic material trapped beneath ice sheets in different parts of the world, which offer information about past temperature fluctuations and rainfall patterns (Figure 16.9).

Figure 16.9 Hidden Clues to History. Because trees can live for hundreds or even thousands of years, during which they experience a variety of environmental fluctuations, clues about these changing conditions are often hidden within the rings in their stumps, which historical climatologists can analyze. (credit: modification of work “The color and width of tree rings can provide snapshots of past climate conditions” by /NASA Climate Kids, Public Domain)

The investigation of such historical clues hidden in the natural world has enabled scholars to identify the ways in which environmental conditions and patterns of human migration and settlement have together shaped the course of human history. In the case of the calamitous fourteenth century, a series of unusual climatic changes led to a chain reaction of competition for resources and desperate attempts to mitigate the damage and despair that defined the century’s first decades.

At the beginning of the fourteenth century, subtle shifts in global mean temperature and rainfall had a profound impact on the climate of the Northern Hemisphere, unleashing devastating famines and plagues across Afro-Eurasia. These events caused significant human hardship, disrupted commerce, and contributed to the decline of once-great empires, even the seemingly impenetrable Mongol dynasty. Although premodern people did not understand these extraordinary environmental shifts, their lives were no less affected by them. In an era during which many people survived on subsistence agriculture, even the slightest change in seasonal weather patterns could devastate crops and result in widespread malnourishment and starvation. Poor nutrition weakens human immune systems, which—together with poor sanitation and the close quarters in which people lived in medieval towns—undoubtedly left many more vulnerable to the ravages of epidemic diseases. This was especially the case when the bubonic plague struck much of Afro-Eurasia by the middle of the century.

To place the dramatic meteorological changes of the fourteenth century in context, we must understand how they relate to larger climate patterns. Long-term weather fluctuations, during which periods of relative warmth and cold alternated over hundreds of years, have long been part of Earth’s ecological landscape and the narrative of environmental history. Within these longer periods of gradual climatological change, however, less predictable short-term fluctuations have also resulted from rapid changes in wind patterns, ocean currents, and seismic activity. From time to time, such erratic climatological shifts resulted in devastating reversals of typical weather patterns.

In the fourteenth century in particular, the Little Ice Age, a period of unusually cold weather that affected most of the Northern Hemisphere (Figure 16.10), led to significant variations in normal rainfall and a general drop in the mean annual temperature. Preceded by a Medieval Warm Period, a span of more temperate climate across the globe from the tenth through the thirteenth century, the cool temperatures and, in some areas, droughts radically reduced available resources and food supplies. Aggravated by rising population levels and declining agricultural productivity, food shortages caused significant hardship and financial distress as famine became commonplace and competition for resources intensified.

Figure 16.10 The Little Ice Age. This chart depicts the shift in the Northern Hemisphere’s temperature over the last millennium, including the Medieval Warm Period that began in the tenth century and the Little Ice Age that ran from the fourteenth century to approximately 1850. (data source: Northern Hemisphere Temperature Reconstruction by Moberg et al., 2005) (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Although a consensus about the causes of the Little Ice Age remains elusive, possible triggers may have included changes in ocean circulation patterns, shifts in the earth’s orbit, and several massive volcanic eruptions in the tropics that released clouds of sulfate particles into the atmosphere and reflected solar energy back into space at the end of the thirteenth century. Ultimately, these environmental changes resulted in an advance of mountain glaciers and an overall mean global temperature decrease of 0.6°C (with some areas experiencing as much as a two-degree drop in annual temperature). This decrease may seem insignificant, but in the absence of modern agricultural and irrigation techniques, it led to catastrophic crop failures and widespread famine in many parts of the Northern Hemisphere within the first few decades of the fourteenth century. The increase in glacier growth, moreover, affected many regions of the world, because the more water turned to ice, the less was available to evaporate and turn into rain. As a result, even areas far from glacial mountains suffered prolonged periods of drought.

Despite their global impact, the effects of the Little Ice Age were not the same everywhere. In the Mediterranean and West Africa, irregular rainfall and periods of drought dramatically reduced crop yields, whereas in China and northern Europe, cold weather and the freezing of lakes and rivers were especially pronounced. Elsewhere in Europe and Asia, in 1314, extraordinary rains began to fall that introduced a period of abnormally cold and wet winters. This deluge of precipitation resulted in poor harvests as people struggled to cultivate already overworked land. Outside Afro-Eurasia, evidence suggests that the North American interior also suffered when established agricultural systems faltered under hotter summers with less rain and colder winters, leading to severe population loss in the southwestern region.

Although the Little Ice Age was especially devastating in the 1300s, its effects persisted for many centuries. In addition to its immediate impact on crops, late medieval climate change led to longer-term deforestation because more wood was used for heating, in the Northern Hemisphere in particular. The climate shift not only altered building designs and clothing styles, which became adapted to colder temperatures, but in some places it also ultimately precipitated the eventual adoption of coal for heating and the beginning of human reliance on fossil fuels.

The period known as the Great Famine of 1315–1317 was a direct result of the Little Ice Age in much of Europe north of the Alps, an area of roughly 400,000 square miles. This widespread and prolonged food shortage prompted one of the worst population collapses in Europe’s recorded history. It is virtually impossible to know the actual death toll, but it is likely that up to 10 percent of northern Europe’s population of more than thirty million perished. Even though crop yields began to rebound in 1317, it took several more years for them to return to prefamine levels. Beyond the devastating loss of lives and human suffering, prolonged food shortages also led to widespread political and economic instability. The prices of necessary food staples like grain skyrocketed, and competition for resources generated social tension, conflict, and an increase in crime. Ultimately, the Great Famine led many to question the ability of church officials and monarchs to respond effectively to crises and catastrophes, which had long-term effects on public trust in these institutions (Figure 16.11).

Figure 16.11 An Allegory of the Great Famine. This image from a fourteenth-century manuscript created in Erfurt, Germany, at the time of the Great Famine depicts Death sitting atop a legendary creature known as a manticore, with famine perched on the fires of hell at the end of the manticore’s tail. (credit: “Death (“Mors”) sits astride a lion whose long tail ends in a ball of flame (Hell). Famine (“Fames”) points to her hungry mouth” by “Mariule”/Wikimedia Commons, Public Domain)

With very few options to remedy the devastation wrought by years of poor weather and famine, most people had little practical recourse other than migrating in search of better conditions. The collective anxiety and social tension of the era sometimes led to scapegoating, including persecutions of supposed witches based on the premise that they had the ability to control the weather as a means of causing others harm. Historians have traced connections between peaks of the Little Ice Age and spikes in witch-hunting activities. Although this type of persecution was by no means universal, it demonstrates the desperation many people must have felt in the face of unrelenting strife.

Mobility and Human Society

Throughout history, economic opportunity and access to new and varied resources have inspired merchants and traders to travel. In the premodern world, this was especially the case along the trade routes of North Africa and the Silk Roads, an active network of trade and commerce that attracted merchants and traders from across Afro-Eurasia (Figure 16.12).

Figure 16.12 Traveling the Silk Roads. This detail from a page of the Mallorquin (meaning “from the island of Majorca off the coast of Spain”) Atlas of 1375 shows the type of trade caravan that traveled through various legs of the Silk Roads journey. Given the length of the route, few merchants covered it in its entirety. (credit: “Caravan on the Silk Road” by Gallica Digital Library/Wikimedia Commons, Public Domain)

Travel was also a common requirement of religious devotion in the tradition of pilgrimage. Muslims desired and were even obligated, by one of the “pillars” of Islam, to complete the hajj, a visit to Mecca and Medina, the holy sites of their faith in modern Saudi Arabia. Many Christian faithful wanted to travel to sacred sites containing relics of the saints, believed to be imbued with special power, and also to the Holy City of Jerusalem, believed to be the site of Jesus’s crucifixion and resurrection. The surrounding area was the birthplace of the Christian Church. Jerusalem was also the site of the holiest of holies of Judaism, the most sacred of spaces where the Temple of Solomon had stood until its destruction by the Romans.

Beyond the demands of trade and religion, however, travel was far less possible for all but a small elite who could afford the time and expense required. Travel narratives and journals written by the select few who could embark on voyages provide much of our knowledge of premodern travel. In particular, the chronicles of Ibn Battuta, a Moroccan scholar who traveled across much of the Muslim world of Asia and Africa in the fourteenth century, offer much insight into the conditions and challenges travelers faced.

At the same time, worsening environmental conditions necessitated travel by many who would rarely have ventured beyond their immediate surroundings but now migrated in search of the resources they needed to survive. Leaving behind all that was familiar in the hope of finding a more stable and hospitable environment, they faced a variety of perils, including regional disputes, adverse weather conditions, illness, and banditry. It was difficult to arrange travel between the many different political entities that existed in the fourteenth century, and crossing borders could be exceptionally risky without the security provided by the presence of established networks or patrons, especially when it came to bandits and lack of access to safe waystations to rest. Moreover, at a time when people were struggling to secure basic necessities, travel was very expensive. Horses, carts, camels, and seafaring vessels were beyond the means of most people, so walking became the most common means of transportation for those in search of new opportunities and resources. Walking eight to ten hours a day, on poor roads and at times in poor weather conditions, likely made the experience all the more grueling for migrants who were already malnourished, weak, and vulnerable to opportunistic infections.

Although some people traveled back and forth across borders, the difficulties and expense of fourteenth-century travel made round trips uncommon. Many were forced to abandon their homes knowing they would likely never return. In times of drought and food shortages, these climate refugees faced precarious situations and uncertain prospects. They could become “strangers in strange lands,” foreigners whose unique customs and cultural practices—including religious traditions, dress, and language—marked them as “other” and worthy of scorn.

For those participating in commerce and bringing luxury goods over long distances for sale in faraway markets, however, the experience of travel could be very different. Though merchants and traders too were often seen as “other,” the goods they carried and their need for logistic support along the way, like food and caravansaries (inns along the common trade routes), directly enriched local societies and gave these travelers a different status.

Whether they were pilgrims, refugees, merchants, or soldiers traveling great distances in the premodern world, people on the move brought with them both the goods and traditions of their homelands. In the fourteenth century, an increase in this long-distance travel by a greater swath of people across Afro-Eurasia helped bring new technologies and traditions over geographic and cultural divides, but the desperation of some travelers meant the process was not without tensions. Beyond this, however, a growing threat in the form of infectious disease traveled with them, too, and it soon had a disastrous impact on society even beyond the droughts and famine that had caused many to abandon their homes.