In 1923, a crippling drought pushed the nomads of the Algerian Sahara as far north as Bou-Saada, just 150 miles south of the Mediterranean coast, in search of sustenance. The French colonial authorities worried that fighting would break out between the nomads and locals over scarce water. From their perspective, indeed, nearly every year between the early 1920s and the late 1940s was exceptionally dry.

But if everything is exceptional, then nothing is. Each year’s rainfall in fact varied considerably from place to place on the edges of the vast desert, and so unpredictably that the variation was wholly unexceptional. The nomads adapted their patterns of movement, and the rhythms of daily life, to accommodate both extraordinary drought and admittedly rare bounty.

The era of human-induced climate change has brought more awareness of the distinction between climate and weather. The “exceptional” droughts of the mid-twentieth century nevertheless raise troubling questions for contemporary Algeria.

Conflict over water at the northern edge of the Sahara did not begin with the colonial period. Nor did it always correspond to periods of drought. Throughout the nineteenth century, and no doubt earlier, tribal confederations on the Moroccan-Algerian border destroyed wells or otherwise denied their rivals access to water. One nineteenth-century Moroccan described the attendant suffering as a fact of life in the desert. Indeed, “the Dawi-Mani‘” on the Morocco-Algerian border “at one time handed over five to ten camels because their herds suffered from thirst,” indicating no compunction on the part of their trading partners about taking advantage of distress. Moreover, the causes of conflict could be petty: Even a business transaction gone awry could spur the use of water as a weapon of war.

Nevertheless, before the French arrived in North Africa, it was easier to resolve the disputes and relieve the misery. In times of drought, desert dwellers called on ties of Sufi practice, commerce, intermarriage and kinship for charity, mediation or determination of punishment.

The colonial intrusion disrupted these ties by drafting rules for nomadic movement, introducing new definitions of property and reordering the labor force. While acknowledging the necessity of migration away from the most parched expanses, colonial administrators begrudged the imposition of the migrants themselves. The logic of population movement -- the need to find water -- remained constant in each “exceptional” year, yet the location of that water and hence the patterns of movement inevitably varied. Migration worked precisely because it was responsive to local conditions and hence irregular. But the French found the arrival of hungry herders and their thirsty flocks destabilizing: Nomads moved without qualm from one jurisdiction to the next, and the extremity of their need made them less likely to respect the arbitrary rules of the colonizers. In the particularly punishing year of 1923, when nomads ventured to Bou-Saada, one captain there ruefully noted that “the delinquents did not truly believe themselves at fault.” Nor should they have -- seasonal migration usually began in the best of years in early summer, yet administrators insisted on advance warning of migration paths as early as March. Such impractical rules more or less invited flouting; no bureaucratic fiat could impose predictability on the rains of arid inland Algeria.

Colonial interest in policing movement had less to do with the suffering of Algerians, or even with fears of unrest, than it did with the protection of property. In years with adequate rainfall, pastoralists would bring their animals to graze on fields after the harvest. In the “exceptional” years of the mid-twentieth century, herds on the brink of starvation would decimate crops. French repression of Sufi orders and other religious networks frayed a crucial safety net for Algerians during lean years, and the redistribution of land to colonial settlers introduced a new variable into the calculus of survival. Colonist insistence on absolute possession, rather than usufruct, of the land conflicted with previous arrangements, not to mention the basic biological need of thirsty, hungry humans and hoofed animals alike. In addition, in the north-central Algerian Sahara in 1925, colonists rented their land to the dispossessed for exorbitant sums. Preying on the illiterate, they offered no proof of contract, and simply evicted the first tenants and re-leased the land to new victims.

Furthermore, political and technological changes in the twentieth century remade labor relations at the edges of the desert. Indigent visitors to agricultural areas had long found temporary work in the fields when times were bad, attesting both to significant local variation in rainfall and a durable, if disorganized, system for ameliorating the difficulties such variation caused. Colonial settlers, an administrator noted, at times preferred not to hire Algerian laborers, in one incident paying French soldiers looking for extra money far more than they would to desperate nomads and pastoralists. It was the rapid mechanization of agriculture that had the larger impact. Scarcely available to Algerian farmers, machines came to dominate the fields of colonial settlers. Combined with settler suspicion of nomads, the advent of mechanical harvesters, combines and tractors exacerbated the poverty of migrant Algerians during lean years, reducing the size of the manual work force that farmers needed and probably lowering wages.

In the 1920s, 1930s and 1940s, the colonial state could not accommodate the climatic variation of interior Algeria yet irredeemably altered centuries-old forms of effective response to drought. Bent on making everything regular and predictable, the French authorities had no way to deal with the suffering of “exceptional” scarcity.

Scientists differ as to how climate change will affect the weather in North Africa. A future of increasing instability and seasonal variation seems likely, however, and another 30-year stretch of “exceptional” years is not out of the question. Perhaps more surprisingly, the challenges of population movement, property and labor may continue to bedevil the Algerian state, nearly one hundred years later.

Climate change will further erode the rural Algerian economy, hastening migration to cities and exacerbating the crises of housing and unemployment there. Although obviously better intentioned than the colonial state, Algeria’s social welfare model leaves many vulnerable in both cities and in the countryside. Whether drought-stricken farmers remain in the bled or decamp to Algiers, they will require new livelihoods, new sources of income and new ways of life.

Property conflict seems at first glance a less likely source of unrest in contemporary North Africa. Nevertheless, as in the American Midwest, the economies of scale and political muscle of corporate agriculture will drive the allocation of resources -- particularly water -- toward further inequality. Algeria has no homegrown Monsanto or ADM, but it faces the additional complication of intense industrial water usage in rural areas by the oil industry. As the economic behemoth in the country, the petrochemical industry will face little pressure to cut back its exploitation of surface or fossil water in the Sahara.

Even the rosiest climate change scenario will fundamentally alter how people, whether in North Africa or beyond, work the land. Moreover, if states in the future do not guard increasingly unpredictable water resources, nomadism as a way of life, always looked at with suspicion by centralized states, is unlikely to survive unmodified. The hungry, thirsty Algerian nomads of the 1920s may reappear in Bou-Saada and points north in the coming decades.