A new study has found that increasing organic carbon in soils does more than store greenhouse gases: it also changes how soils hold and distribute water, with benefits that are especially significant in dry and water-limited regions. The research was led by Dr. Inne Vanderkelen and Professor Edouard Davin, in collaboration with Wyss Academy colleagues Marie-Estelle Demory and Myke Koopmans, the University of Bern, and the National Center for Atmospheric Research in the United States. Using a global land-surface model, the team ran simulations based on realistic soil carbon sequestration scenarios, including one aligned with the international “4 per 1000” initiative, which proposes increasing soil organic carbon stocks by 0.4% per year as a lever for climate action.

The results show that carbon-enriched soils retain more water in the root zone, reduce water stress for plants, and shift the balance of water away from runoff and toward ecosystem use. While the effects are modest when averaged globally, they are consistent and most pronounced in regions already facing water scarcity, such as the western United States, the Sahel, and parts of southern Africa 

The findings add to a growing body of evidence that nature-based solutions can deliver multiple benefits at once. Soil carbon sequestration, the study suggests, should be understood not only as a climate mitigation strategy but also as a tool for climate adaptation, helping ecosystems and agricultural systems become more resilient in the face of increasing drought, especially where water is already scarce.

The research strengthens the scientific case for integrated land management that addresses climate resilience, sustainable land use, and water security together.

The paper was published on 11 June 2026 in Biogeosciences (Vol. 23, pp. 3829–3854). (DOI: 10.5194/bg-23-3829-2026 )

Figure 4.9 in Caretta, M.A., A. Mukherji, M. Arfanuzzaman, R.A. Betts, A. Gelfan, Y. Hirabayashi, T.K. Lissner, J. Liu, E. Lopez Gunn, R. Morgan, S. Mwanga, and S. Supratid, 2022: Water. In: Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 551-712, doi:10.1017/9781009325844.006.