Hydrogen gas formed by natural processes in the subsurface of mountain ranges could represent a promising source of clean energy. A new international study led by Unil and GFZ shows that erosion plays a key and complex role in the formation and accumulation of this natural resource. This research confirms that the Pyrenees and the Alps could constitute key targets for natural hydrogen exploration.
What if mountain ranges such as the Alps or the Pyrenees concealed a source of clean energy beneath our feet? In 2025, a widely publicized study published in Science Advances and coordinated by the GFZ Helmholtz Centre for Geosciences showed that certain mountain belts could provide favourable conditions for the formation and storage of natural hydrogen (H₂).
Now, a new international study published in Journal of Geophysical Research: Solid Earth builds directly on this work, highlighting the decisive role of rock erosion in both the formation and potential reduction of these hydrogen accumulations. "Unexpectedly, erosion turns out to be a key and ambivalent factor in natural hydrogen production," says Frank Zwaan, lead author of the study, formerly at GFZ and now a researcher at the Faculty of Geosciences and Environment of the University of Lausanne (Unil), with visitor status at the University of Fribourg. "This research supports the view that the Pyrenees and the Alps are key targets for natural H2 exploration."
Hydrogen and the energy transition
The motivation behind this research stems from a major challenge: energy. Hydrogen could play a central role in the energy transition, thanks to its strong potential to power vehicles and decarbonize industrial processes. Yet today, its production still largely relies on polluting fossil fuels, while hydrogen production powered by green energy remains costly. In this context, the potential presence of exploitable natural hydrogen in the subsurface of mountain ranges such as the Alps or the Pyrenees appears as a promising avenue.
In these regions, tectonic plates first moved apart millions of years ago, forming rift basins, before converging and colliding to give rise to mountain ranges. As a result of these processes, rocks from the deep mantle were gradually brought closer to the surface, reaching conditions where temperatures allow them to efficiently react with water and release hydrogen (H₂), a chemical process known as serpentinization. The gas produced may then accumulate in porous rock layers that act as reservoirs, which could then be exploited for targeted applications.
"We already know that the Earth produces large amounts of hydrogen, and local-scale exploitation is already ongoing in Mali. The key question now is whether large-scale hydrogen accumulations can be found, because, as with petroleum systems, very specific conditions must be met, with all key elements in place at the right time," explains Frank Zwaan.
In their new study, the scientists used advanced numerical plate tectonic models to highlight the influence of a key factor that acts as a delicate regulator: erosion. Their models show that erosion can promote the uplift of mantle rocks toward the surface, which improves the conditions for serpentinization and therefore increases the potential for natural hydrogen generation. By contrast, erosion that is too rapid or too intense can reduce this potential, either by destroying reservoir rocks or by altering the temperature conditions required for hydrogen formation.
The simulations also point to another critical factor: the geological history of the regions studied. The duration of tectonic extension phases, long before mountain building, also influences the potential for hydrogen generation.
By comparing different mountain belts, the researchers show that not all ranges have the same potential. In the scenarios examined (the Alps, the Pyrenees, and the Betic Cordillera in Spain), the Pyrenees appear to be very favourable while also the Alps represent interesting potential. "These new results give us a better idea of where to investigate," says Frank Zwaan. "However, further research is essential to more precisely determine where natural hydrogen resources might be explored," he concludes.
Source: F. Zwaan, A. C. Glerum, S. Brune, D. A. Vasey, J. B. Naliboff, G. Manatschal and E. C. Gaucher, The Impact of Erosion Efficiency on Rift‐Inversion Orogen Evolution: Implications for Serpentinization‐Derived Natural H2 Resources, Journal of Geophysical Research: Solid Earth, 2026, DOI : https://doi.org/10.1029/2025JB033255
