The solution to stop the expansion of the Sahara no one is talking about

A massive restoration effort is currently underway across the Sahel to combat land degradation and halt the southward expansion of the Sahara Desert. Countries spanning the continent including Senegal, Ethiopia, Niger, Nigeria, Burkina Faso, Mali, Chad, Mauritania, Eritrea, Djibouti, and Sudan have engaged in wide-ranging replanting initiatives. So far, they've restored about 20-30 million hectares, representing 20-30% of their ambitious 100 million hectare goal by 2030.

These efforts have evolved significantly over time. What began as regimented tree-planting in monoculture patterns has transformed into a more sophisticated approach that integrates indigenous farming practices like zai pits (similar to permaculture swales), holistic restoration techniques such as Forest Managed Natural Regeneration, and community empowerment for sustainable land management.

However, there's another crucial path that would complement these Sahelian restoration efforts, one that remains largely overlooked in current discussions. There is a key supplier of rain to the Sahel and Sahara that lies to the south, largely unnoticed in restoration efforts: the Congo rainforest.

What's happening in Africa mirrors developments in South America, where scientists have traced how the Amazon rainforest provides rain to downwind countries like Bolivia, Paraguay, Argentina, and Uruguay. The Amazon breathes water into the atmosphere, and that moisture travels vast distances. This knowledge has entered public and political discourse, shaping calls to protect the Amazon despite continued deforestation.

Africa's atmospheric connections have been more forgotten, but researchers are beginning to reveal these hidden links. UCLA atmospheric scientist Rong Fu discovered that Amazon forests begin transpiring more water one to two months before the wet season arrives, essentially breathing the wet season into existence. Scientists Makarieva and Gorshkov reached similar conclusions. Fu then collaborated with Sarah Worden and others to demonstrate that the same phenomenon occurs in the Congo. The rainforest's transpiration alters large-scale atmospheric circulation, drawing in ocean moisture and initiating earlier wet seasons. (Heres a previous article from this newsletter on her work.)

[Congo rainforest]

Researchers Ruud van der Ent and Hubert Savenije mapped the invisible global pathways of moisture, tracking where it rises from land and where it returns as rain. [van der Ent 2010]. In Europe, water evapotranspired in the west falls again in the east. On the US west coast, evapotranspiration travels across the continent, falling as rain throughout the middle of the country, the east coast, and into Canada.

Their mapping revealed something particularly significant about Africa. The Congo Basin serves as a major moisture source for Sahel rainfall. As they noted in their research: "The Congo basin in its turn is a major source of moisture for rainfall in the Sahel."

The most read article in this newsletter is on van der Ent and Savenije’s work - it’s called “The map of the small water cycle” . The map gives us a both gestalt sense and detailed quantifiable data on water moisture transport. Its a map of the flow of moisture across the globe in its dance between air, land, and ocean.

Since 1990, the Congo has lost over 20 million hectares of forest. In 2024 alone, it lost more than 1 million hectares due to mining, logging, fuelwood harvesting, and small-scale agriculture. This destruction directly impacts the Sahel, but it has escaped the consciousness of African populations, governments, and NGOs due to our compartmentalized view of ecosystems. Ecologists aren't yet working with cutting-edge atmospheric scientists to understand how evapotranspiration in one ecosystem affects water supply in another region thousands of miles away. Our restoration efforts remain disconnected from atmospheric considerations.

This compartmentalization reflects what Michel Foucault identified as the disciplinary organization of knowledge: how information gets partitioned into bounded domains that obscure the very connections sustaining life. Our ecological understanding hasn't yet advanced beyond disciplinary boundaries that fragment what should be understood as flowing, interconnected systems.

Just as healing one organ in the human body can promote healing elsewhere through interconnected systems, the earth operates similarly. James Lovelock's concept of Gaia and geophysiology comes to mind here. The Congo rainforests function like a heart pumping the earth's lifeblood, which is water, but when destroyed, that vital circulation fails to reach other parts of Africa.

These are called teleconnections in atmospheric science, where one region impacts another hundreds or thousands of miles away. This isn't merely an intriguing connection; it's key to understanding the earth’s circulatory system and it’s way of regulating itself. (For more on teleconnections see research by scientists like Roni Avissar, and Abigail Swann. For the idea of water as the lifeblood of the earth see Wilhelm Ripl’s work.)

Our water management practices and restoration efforts must expand to embrace this broader, atmospheric understanding. To truly succeed in restoring the Sahel and halting Sahara expansion, focusing solely on local efforts isn't enough. It's equally critical to halt destruction and actively support restoration programs within the Congo Basin, recognizing its indispensable role as a rain provider for the Sahel. The understanding of, and acting on these atmospheric connections, helps to heal the interconnected systems that sustain life across the African continent.

Addendum: I found out after writing this that Douglas Sheil has written a good overview paper on this Central Africa region generating rainfall for rest of Africa e.g. 40% of Sudan’s rain comes from Central Africa

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References

Avissar, Roni, and David Werth. "Global hydroclimatological teleconnections resulting from tropical deforestation." Journal of Hydrometeorology 6, no. 2 (2005): 134-145

Ripl, Wilhelm. "Water: the bloodstream of the biosphere." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358, no. 1440 (2003): 1921-1934. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020JG006024

Swann, Abigail LS, Marysa M. Laguë, Elizabeth S. Garcia, Jason P. Field, David D. Breshears, David JP Moore, Scott R. Saleska et al. "Continental-scale consequences of tree die-offs in North America: identifying where forest loss matters most." Environmental Research Letters 13, no. 5 (2018): 055014

Worden, Sarah, Rong Fu, Sudip Chakraborty, Junjie Liu, and John Worden. "Where does moisture come from over the Congo Basin?" Journal of Geophysical Research: Biogeosciences 126, no. 8 (2021): e2020JG006024

Van der Ent, Rudi J., Hubert HG Savenije, Bettina Schaefli, and Susan C. Steele‐Dunne. "Origin and fate of atmospheric moisture over continents." Water Resources Research 46, no. 9 (2010).