Climatic alterations, with the consequent droughts and natural disasters, are one of the great drivers of migration. That is why specialists assume that global warming will cause, and in fact is already causing, an extraordinary migratory flow. But this phenomenon is not new. Although many great historical events have entered textbooks as military invasions, in reality, their origin obeys a pattern behind which is a climatic anomaly. One of them is, according to a group of researchers from the CSIC and the University of Granada, the well-known arrival of the Muslims to the Iberian Peninsula at the beginning of the 8th century, in which the terrible drought that took over had a decisive influence. the region in the immediately preceding years.
The speed of the fall of the Visigothic kingdom before the Muslim push, between the years 711 and 726, has been the subject of a debate among historians from which it appears that such a sudden collapse could only be explained by a weakness that had already existed before. The historian José Soto Chica, who has participated in the research, explains that “the political and social structures of the Visigothic kingdom, which had dominated the Peninsula for three centuries and which had been one of the most prosperous in the West, began to collapse from from the year 680.”
What was the reason? Some Mozarabic chronicles indicate that from the end of the 7th century there was a long period of lack of rain and abnormally low temperatures, which would have resulted in poor harvests and famine. In an eminently agricultural society, these circumstances could very well be responsible for the social and political instability of those years, but specialists did not give much credence to the written sources of the time.
A group of scientists set out to look for evidence that would corroborate the severity and impact of that drought in other ways. And, as they point out, they found them. Another member of the team, paleoclimatologist Jon Camuera, explains that the researchers studied remains of pollen as well as the formation of stalagmites in caves in the Iberian Peninsula and Morocco in search of clues. They concluded that the long episode of drought and cold did indeed occur and that it was serious. “We detected, for example, the proliferation in that period of artemisia, a plant that grows in very dry environments,” says Camuera. A modest plant would therefore constitute one of the main proofs of why the Muslim domination of the Peninsula began.
On the other side of the Strait of Gibraltar, as confirmed by the group of scientists who published their work in Nature Communications, the climatic conditions were not better. Soto Chica argues that the same factors that caused the collapse of the social and political structures of the Visigoths, for the population on the other side of the Mediterranean, were a stimulus to look further north for the solution to their problems. “Surely in North Africa they were just as bad as the peninsular population,” he points out, “but facing hunger and hardship as a conqueror is not the same as facing the conquered.”
However, researchers are cautious about whether the climate was the only factor that motivated the invasion, although they do assume that it was a very important element in the beginning of the period of Muslim domination that would last for centuries. If the climate issue was so important, one might wonder if the conquest of the Peninsula was a migratory rather than a military movement. “Maybe it was both things,” the historian clarifies, “because it is not strange that in the past they have mixed and violent migrations have occurred.”
Soto Chica alludes to other similar phenomena that, although they are basically remembered as military operations motivated by the ambition of leaders or monarchs, are actually due to subsistence migratory movements of populations highly dependent on agricultural production. This chapter would include, for example, the very strong pressure of the barbarian peoples on the late Roman Empire.
Although the causes of the fall of the Western Roman Empire have been the subject of a very long historiographical debate, there are numerous specialists who point in this direction. For example, historian John L. Brooke, author of Climate change and the course of global history, points out that the entry of large migratory flows and the Germanic invasions were due to the fact that the conditions Climatological conditions in their places of origin had worsened to such an extent that these peoples were forced to look for new resources and new cultivation areas. A weakened Rome could not face them.
Nor could he face the feared Huns who devastated much of the empire in the middle of the 5th century. Recent research from the University of Cambridge indicates that a severe drought between the years 430 and 450 abruptly modified the traditional ways of life of this people, until then peaceful, which went from basing its subsistence on pastoralism to crossing the Danube to obtain new resources by blood and fire.
The same could be said of the expansion of the Mongol empire in the 13th century, according to the results of paleoclimatic analyzes carried out in 2014 by American scientists. Their conclusions indicate that shortly before Genghis Khan unified the Mongol tribes and began his conquests, there was a long period of drought for which the only solution was precisely the conquest of new territories. The common characteristic of these examples is that their ultimate motive is a subsistence crisis as a result of climatic anomalies and not the political or territorial ambition of their leaders.
Today’s climate migrations are no longer armed, they cannot even be considered invasions although some conspiracists think otherwise. But they are going further, as numerous studies confirm. To give some examples, a few years ago, researchers from the New Zealand University of Otago pointed out that climate anomalies have recently become the main cause of migration to OECD countries. And in 2021 the UN pointed out that global warming will cause more than 200 million displaced people by the year 2050 and that taking into account only internal emigration. Although currently these large population movements are not capable of putting an end to states and regimes, they do, as is demonstrated almost daily, maintain intact their capacity to question the political and social stability in the receiving countries.
