Mauritania can be classified as a relatively safe country (see also the assessment by the German Foreign Office (https://www.auswaertiges-amt.de/de/ReiseUndSicherheit/mauretaniensicherheit/219190#content_0). In addition to the Mauritanian government bodies, traditional cultural leaders, who have already participated in the previous planning events, also promote and support the project.
SAREP addresses nearly all SDGs of the United Nations. SAREP is not a development aid project; it operates as a green business project at eye-level with Mauritania.
It contributes, inter alia, via:
– The substitution of food imports
– The issuance of CO2 certificates
– Creation of permanent jobs
– Emigration prevention
– Education: Development and local know-how in the agricultural and forestry sector
– Providing municipal water supply
– The production of hardwood pellets for thermal use, as industrial C source (export)
– The production of bio-oils, food for local market, fuel for diesel engines (local & export)
– The production of feed protein (local & export)
– The production of certified food products (local & export).
Mauritania is a transit country for migrants heading north and to Europe, by land to Libya and by sea to the Canary Islands. Since these people are largely making their way because of the lack of economic prospects prevailing in their homeland, the project offers real alternatives with at least 2,000 permanent jobs per 10,000 ha unit. The traditional leaders explicitly welcome the creation of prospects for their children and grandchildren. Permanent jobs, secure incomes, migration prevention create social peace, reduce the breeding ground for extremist ideas, increase food security, create export commodities and improve civil society in the sense of good governance.
In the Sahel, innovative land use would clash with existing land use patterns. Conflicts with pastoral societies (transhumance) should be avoided.
Previous efforts to achieve greening in the Sahel have been based on rain-fed agriculture, or attempts to prevent daily overgrazing and to make plant and tree growth possible from cane. In general, these aid approaches aim to improve community water supplies and seek to provide local people with safe access to water and support local subsistence agriculture. SAREP aims at active industrial irrigation for the production of wood, carbon sinks, energy and food in the southern rim of the Sahara, avoiding conflicts with previous land use patterns and creating secure jobs on a large scale – keyword migration prevention. Irrigation uses seawater desalinated with renewable energy (wind and solar). The quantities of water produced are large enough to take over aspects of municipal water supply on the side.
As a green business, SAREP represents a strategic investment in climate protection, resource security and regional development. The project exclusively uses already existing technologies and research results.
The project assumes an IRR above 10%. Therefore, due to the economic viability, also in view of the required dimensions, a market-based financing can be assumed. Mauritania, as a partner of the project on an equal footing, has access to transnational financing opportunities, such as through the ADB or the EIB.
On the sales side, there is high demand for SAREP products:
– CO2 certificates for the upcoming decarbonization of the economy
– Food security and local food import substitution
– Energy /wood pellets as a downstream energy source after fossil fuels
– Bio-oil as fuel
No. Before the start of the project implementation, an environmental impact assessment will be conducted. More detailed information about potential interactions with several climatic or hydrological mechanisms can be found in the “Publications” section of this website.
In Mauritania, the Sahara desert borders the Atlantic Ocean. Using renewable energy (wind and PV) the seawater is desalinated via reverse osmosis. Already existing market-proven technologies are used for this that only are to be adapted in the dimensioning.
The price of water depends on the production capacity of the desalination plant. As an upscale effect, a price below 0.50 € /m³ is expected. Currently, water from the Senegal River, which has mainly been used for the Mauritanian water supply until now, costs several times more. Considering the very large water supply capacity of SAREP, it is possible to supply e.g. the capital, Nouakchott.
After desalination with reverse osmosis, the remaining brine contains twice as much salt compared to seawater. This brine can be used to replenish a historical dry salt lake north of Nouakchott. Here (on an area of about 4000 km²) the water content could be further reduced via evaporation and thus enable the future extraction of salts and metals from the brine.
Water is pumped through pipes with solar pressure boost in the inland. The extension of the water pipeline eastward to Mali is feasible. Goods for export reach the capital in the south or the overseas port in the north via the N2 highway. Transporting energy pellets from West Africa to Europe costs less than 5% of the energy they contain. The calorific value is higher than that of lignite.
If we reverse-engineer the calculations, starting with a target of 160 tCO2/ha/a, the presented calculations unveil essential insights into carbon sequestration and biomass dynamics within the realm of tree cultivation. According to Dr. Ohlde’s estimation, the carbon dioxide sequestered is projected to be 160 tCO2/ha/a. This yields to 43.6 tC/ha/a using the carbon conversion factor 3.67. Considering 48% is the percentage of carbon in the dry matter content, the composition of the trees would have been 91 tDM/ha/a (Carneiro et al., 2021). Similarly, the fresh matter content is approximated at 186 tFM/ha/a, constituting 50% of the total matter. Over a span of 30 years, the fresh matter content reaches 5,571 tFM/ha. In terms of above-ground biomass, excluding roots, is estimated to be 75% of the total fresh matter (Maghembe et al., 1983). Therefore, we get 4,781 tFM/ha. Notably, the stem biomass, excluding branches and foliage, represents 57% of the total (He et al., 2018). Thus, the total fresh matter becomes 2,381 tFM/ha. Taking the product of the fresh matter amount and the density of Prosopis Juliflora, which is 0.85 kg/l, we can obtain the volume, subsequently calculating the diameter of the trees (Saraswathi & Chandrasekaran, 2016).
The calculations assume that 1,548 trees will be planted in 1 ha. This means that each tree will be in a square area of 2.54m x 2.54m. All three scenarios below aim to store the same amount of carbon, but the maximum height and diameter of the trees and their distribution will vary as follows.
Scenario 1: if the tree’s maximum height is 8màthe diameter is 0.54m and the distance between trees will be 2.00m
Scenario 2: if the tree’s maximum height is 10mà the diameter is 0.48m and the distance between trees will be 2.06m
Scenario 3: if the tree’s maximum height is 12mà the diameter is 0.44 and the distance between trees will be 2.10m
Investors should be able to implement their goals in sufficiently large units. Options include compensation via certificates, production of sustainably produced food, production of organic vegetable oils as food or fuel.
In each unit, staple food crops are grown for local supply.
About 3,000 ha per 10,000 ha unit.
For the tree shelterbelt, about 11,000 m³/yr.
For agricultural crops up to 16,000 m³/a.
For Jatropha about 9,000 m³/a.
Afforestation has several advantages compared with other methods of carbon sequestration like “Direct Air Capture”. Afforestation in the SAREP context utilizes market-proven technologies and an additional value creation through the utilization of by-products is achieved. A more detailed comparison can be obtained from the “Publications” section of this website.
For phytosanitary and fire hazard reasons, the following mix of species, adapted to the given environmental conditions, was chosen: Prosopis, Acacia, Casuarina, Eucalyptus and Tamarix.
Prosopis is highly adapted and extremely productive, as the species is a legume. It is a premium hardwood that could also be used for furniture production. Prosopis cannot escape from the SAREP units in the middle of the Sahara because there is no water available in the surrounding area without irrigation.
Bamboo needs much more water and is a woody grass, no wood. It has a very high SiO2 content, which requires a more complex processing. Advantages exist only with an existing processing culture and technology, which both are not available in Africa. Biomass production is only between 10 and 35 tDM/ha/a.
Per ha the shelterbelt grows by 80 t DM/ha/a. That is 40 tC/ha/a. In CO2, this is 144 tCO2/ha/a.
Jatropha curcas requires only 50% of the water required for oil palm cultivation per ha. In terms of oil production, Jatropha has favorable water use efficiency; Soybean oil requires more than 100% more water for one liter of oil.
Production parameters in oil-crops
Yield (kg oil/ha)
Jatropha curcas: 2000
Land consumption (ha/kg oil)
Jatropha curcas: 0,0005
Water consumption (m³/kg oil)
Jatropha curcas: 4,5
Water consumption (m³/ha)
Jatropha curcas: 9000
Oil from Jatropha curcas is used as cooking oil, lamp oil or fuel. It can be used to run all diesel and marine engines (e.g. Mercedes CDI engines). It mixes perfectly with mineral fuels. It can also be reprocessed into jet fuel. Lufthansa has practically proven this. The worldwide demand is very high.
Breeding efforts over the past 15 years have produced high performance varieties. There are still varieties containing “toxic” phorbol esters, but also phorbol ester-free varieties as well as hybrid seeds are available. There is now a simple patented process for “detoxifying” phorbol ester-containing varieties.
The press cake has a crude protein content of 60%. The biological value of over 60% is even superior to that of soy protein. Jatropha cake can directly replace soybean as a protein component in animal feed and, as a by-product of oil production, does not have to be imported. Thus, it is another product “Made in Mauritania”.
In addition to the harvested oil, Jatropha curcas sequesters about 25 t CO2/ha/yr being a permanent crop.
Moringa oleifeira belongs to the behen nut family (Moringaceae), also called horseradish tree. Moringa is grown in permanent culture. The leaves of the Moringa tree contain all essential amino acids and fatty acids, as well as a wide range of vitamins and minerals. Behen oil is extracted from the seeds, which can be used as a lubricating oil, salad oil, for soap making, and in cosmetics. Ground seeds coagulate and precipitate water contaminants.
Existing cultivation techniques and crops used in local rainfed agriculture are NOT cultivated. The choice is mainly made for staple food crops that are also cultivated in successful irrigation farming, e.g. in Australia or in the southwest of the USA.
“Mini-Review on Jatropha Curcas” by Dr. Gerhard Ohlde, 09/2023