The newly completed research report from St1 confirms that increasing vegetation that sequesters CO2 from the atmosphere and at the same time brings other benefits locally is possible, even in dry and long-barren conditions. Carbon sinks created by new vegetation offer a significant tool for mitigating climate change, increasing the earth’s green cover and at the same time substantially improving local living conditions.
Energy company St1 ran a pilot project in Morocco between 2018 and 2022, during which fast-growing tree species were planted in an arid area and their ability to form a significant, measurable carbon sink was studied. The aim of the pilot was to find an optimal solution for cost-effective forest growth and carbon sequestration with the help of soil improvement and irrigation systems. The pilot was carried out in cooperation with the local university, Université Mohammed VI Polytechnique. The Natural Resources Institute Finland LUKE directed and monitored the field tests at the plantation area in Benguerir.
The improvement of local conditions is an important factor
The pilot project studied seven tree species and found that eucalyptus, moringa, and carob trees sequestered the most CO2 per hectare. Among the irrigation methods used, the underground drip irrigation system promoted growth most effectively. No differences in terms of growth were observed between peat and biochar, the two soil improvement products tested in the study. The total pilot area amounted to 3.7 hectares, and a small-scale agroforestry trial was also carried out between the planted trees. All tree species and crops planted in the area for the purpose of the project were locally relevant.
The results of the pilot suggest that under conditions similar to the pilot area, the most viable option for maximizing carbon sequestration and crop production involves a mixed system. Key components of this system include moringa and carob trees as the primary species, complemented by shrubs, other crops, or alleys with quinoa and fava beans. Eucalyptus trees could be incorporated as windbreakers. In general, afforestation projects should improve local food production in places where it is absolutely needed.
A functioning market is needed for carbon sequestration
The example calculation made on the basis of the two-year results of the pilot study shows that the cost of sequestering one tonne of CO2 using the mixed plant system within the specified conditions amounts to approximately EUR 97. The cost of the sequestered CO2 includes two years’ worth of non-recurring expenses related to the establishment of the plantation and maintenance costs for the same duration. Within conditions similar to the pilot project, a significant portion of the expenses would arise from the renewable energy-powered irrigation system. During the first few years, the seedlings establish roots and experience accelerated growth. In typical circumstances, the life cycle of the carbon sink naturally exceeds two years, after which the cost of the final sequestered tonne of CO2 will be influenced by the trees' growth rate, variations in growing conditions, and the irrigation requirements.
"The pilot demonstrates that despite extremely challenging conditions, the implementation of afforestation is technically feasible. Although the cost level of a carbon credit calculated on the basis of the pilot, is higher than the average in the current voluntary carbon market, it nevertheless provides a multi-faceted and truly additional approach to mitigating climate change. It would be prudent to more ambitiously develop also mandatory legislation to expedite the funding and widespread launch of similar initiatives,” says Ville Hulkkonen, St1's Director, Public Affairs.
St1, Ville Hulkkonen, Director, Public Affairs, tel. +358 44 077 7226
St1, Anniina Lampinen, Carbon Sequestration Specialist, tel. +358 40 184 0163
Moroccan pilot project research report: Carbon farming and afforestation in arid zones