For centuries, the inhabitants of the Algerian Sahara found ways to adapt to extreme temperatures without electricity. The study "Inventory of ancestral modes of adaptation to high air temperatures in the Algerian Sahara" by Mohammed Faci and others gathers the climate-adaptation customs handed down across generations and groups them into two categories: how houses are built and the habits of daily life.
In the fortified villages (the ksour), the dwellings are built close to one another, with very few façades exposed to the sun and narrow, winding alleys that stay permanently in shade. As they narrow, the alleys speed up the cool evening air, producing an effect similar to pinching a hose. The houses are closed off from the outside and open to the sky through an inner courtyard, the patio, which in the M'Zab is covered by a mesh (the "Chebeq") and oriented at 45°, so that it remains shaded in summer yet lets the sun in during winter.
The walls work against the heat too. Between 70 cm and 1 m thick, they are made mainly of stone, earth (Toub) or gypsum, materials that absorb heat very slowly and release it at night. In the Oued Souf, for example, walls of desert rose and gypsum ensure a difference of up to 10 °C between outside and inside. Small openings of 10–20 cm keep the air circulating, while domes and vaults, with holes of 10-30 cm, let the hot air escape upwards. In summer people sleep on the terrace (the "Stah"), which is cooler, and the walls are coated with light-coloured lime to reflect the light. Those who can afford it dig out a cellar to shelter in during the hottest hours.
Turning to the everyday habits: families move around inside the house following the cool, and some relocate for the whole summer (June to September) to the milder palm grove. Work is done at dawn and in the late afternoon, avoiding the central hours of the day; the air is cooled with porous terracotta jars, people eat fruit, vegetables, milk and dates instead of hot meals, and they wear loose, light-coloured cotton garments such as the Gandoura and the Malhfa. Traditional remedies are not lacking either, such as henna-and-onion compresses.
The figures, however, also point to a loss of these customs. While 86% of those interviewed feel that temperatures have risen over the past twenty years, these techniques are disappearing: today traditional materials are used in only 6% of cases, and eating habits (95%) and traditional clothing (81%) have largely been abandoned. Food preservation has changed in 98% of cases and water cooling in 99%, now entrusted to refrigerators and cold rooms.
Heat waves can kill: an estimated 70,000 people died in Europe in 2003 and more than 55,000 in Russia in 2010. Algeria is increasingly affected as well. Since the 1990s the number of hot days has been rising, and in the Sahara it has grown by more than 50%, to the point that for about 5.5 months a year the population lives in conditions of severe thermal discomfort.
Faced with this problem, modern technological solutions receive a great deal of attention, while the methods that desert populations have refined over centuries remain little studied. As cities expand, many of these practices have been abandoned and risk being lost. This is precisely where the study comes in: to document them before they disappear and to understand how they might be brought back into climate-change adaptation strategies.
To collect the techniques reported in the study, the researchers carried out a field survey from May 2017 to July 2019, travelling across the nine areas of the Algerian Sahara: Saoura, Gourara, Touat, Tidikelt, the M'Zab valley, Oued Rhir, Oued Souf, Tassili n'Ajjer and Hoggar, regions where the sun shines for an average of 7 to 10 hours a day.
A total of 350 people were interviewed, selected from among those who hold this knowledge: elders, notables, researchers and local officials (women make up 7%; 42% are under 50, 38% between 50 and 60, and 20% over 60). The team used semi-structured interviews based on a guide of 41 questions, 6 of them open-ended to leave room for personal accounts, tested beforehand with a pilot in Taghit. Each interview lasted between 15 minutes and an hour and a half.
The study "Inventory of ancestral modes of adaptation to high air temperatures in the Algerian Sahara" by Mohammed Faci and others gathers the climate-adaptation customs handed down across generations and groups them into two categories: how houses are built and the habits of daily life.
In the fortified villages (the ksour), the dwellings are built close to one another, with very few façades exposed to the sun and narrow, winding alleys that stay permanently in shade. As they narrow, the alleys speed up the cool evening air, producing an effect similar to pinching a hose.
Turning to the everyday habits: families move around inside the house following the cool, and some relocate for the whole summer (June to September) to the milder palm grove. Work is done at dawn and in the late afternoon, avoiding the central hours of the day; the air is cooled with porous terracotta jars, people eat fruit, vegetables, milk and dates instead of hot meals, and they wear loose, light-coloured cotton garments such as the Gandoura and the Malhfa. Traditional remedies are not lacking either, such as henna-and-onion compresses.
As cities expand, many of these practices have been abandoned and risk being lost. This is precisely where the study comes in: to document them before they disappear and to understand how they might be brought back into climate-change adaptation strategies.
