The Sahara Desert is known for its extreme temperatures and arid conditions, but it is not immune to rare weather phenomena. In recent years, the region has experienced unusual events such as snowfall and extreme rainfall, which have transformed the landscape. These events are not only surprising but also provide valuable insights into the desert’s climate and its potential future.
Extreme Weather Events
In January of last year, the Copernicus Sentinel satellite captured images of snowfall on the peaks of the province of Béchar, Algeria. This phenomenon is not unprecedented, as similar events have occurred in the past, such as in March 2018, when a storm covered the sand with a layer of snow in Ain Sefra. Additionally, consecutive snowfalls were recorded in December 2016 and January 2017 in Northern Sahara.
Cold Winters in the Sahara
Despite the scorching temperatures during the summer, winters in the Sahara can be quite cold. In mountainous areas, such as the Tibesti massif, ground temperatures have reached -17°C, according to satellite data. This suggests that the air temperature probably dropped below -10°C, highlighting the severity of the climate in certain regions.
Snowfall and Extreme Rainfall
In September 2024, an extratropical cycle brought intense rains to the region, creating lakes in areas such as Sebkha el Melah, Algeria, and near Erg Chebbi, Morocco. The rainfall was equivalent to a full year, and satellite images from NASA’s Landsat 9 showed how Sebkha el Melah transformed from a dry bed to a lake covering 191 square kilometers.
Ephemeral Lakes and Climate Change
These extreme events are not only natural spectacles but also provide insights into the region’s climatic past. NASA Earth Observatory researcher Joëlle Rieder highlighted that similar events have been recorded only twice since 2000, in 2008 and 2014. Ephemeral lakes like these can show us the climatic past of the region and help us understand how the desert’s climate may evolve in the future.
The Sahara’s Humid Past
The Sahara’s current extreme phenomena may be linked to its past, when the desert was a greener and more humid environment. During the African Humid Period, which occurred between 11,000 and 5,000 years ago, the region was home to vast lakes, abundant flora, and diverse fauna. Cave paintings from ancient inhabitants provide evidence of this past, showing hunting scenes and daily life in a surprisingly fertile environment.
Climate Models and Debate
While some climate models fail to replicate the rainfall needed to sustain the great lakes of the past, recent studies suggest that extreme rainfall events, similar to those of 2024, could have played a crucial role. According to Dr. Moshe Armon, these events could have kept the lakes partially filled for years or even decades, highlighting the importance of studying ephemeral lakes to predict the desert’s climate evolution.
Future of the Sahara’s Climate
Analyzing these events raises questions about the future of the Sahara in the context of climate change. The Intergovernmental Panel on Climate Change (IPCC) projects that some desert areas could become wetter, while others would experience greater aridity. As Armon points out, studying ephemeral lakes is key to predicting how the desert climate could evolve in the coming decades.
The Sahara is a complex climate system, influenced by a multitude of factors, from global atmospheric circulation to ocean currents. The interaction of these factors makes it difficult to predict exactly how the climate will evolve, but understanding the region’s past and present can provide valuable insights into its potential future.