As the energy transition gathers steam, naturally occurring hydrogen gas (H2) generated by the serpentinization of mantle rocks is a highly promising sustainable alternative to fossil fuels. To undergo serpentinization, mantle rocks that are normally situated at great depth need to be brought closer to the surface by plate tectonics and other geodynamic processes. Here, they may react with water to be efficiently serpentinized and generate natural H2, which can accumulate in reservoirs as it migrates to the surface (as part of a natural H2 system).Exploring natural H2 systems requires a solid understanding of their geodynamic history, which can be informed by numerical geodynamic modelling. Through such modelling we can trace how, when, and where mantle material enters the serpentinization window, as well as when active, large-scale faults penetrate exhumed mantle bodies allowing for water circulation, as well as serpentinization and H2 generation, to occur.Our recent modelling of rifting and subsequent rift inversion (Zwaan et al., in press) shows that, although serpentinization-related natural H2 generation is a phenomenon best known from (magma-poor) rifted margins and oceanic spreading ridges, annual volumes of natural H2 generated during inversion may be up to 20 times higher than during rifting, due to the colder thermal regime in rift-inversion orogenic environments. Moreover, suitable reservoir rocks and seals required for natural H2 accumulations to form are readily available in rift-inversion orogens, whereas they may not be present when serpentinization occurs in deep marine continental rift or oceanic spreading settings.Our model results thus provide a first-order motivation to turn to rift-inversion orogens for natural H2 exploration and are supported by indications of natural H2 generation in rift-inversion orogens such as the European Alps and Pyrenees.REFERENCE CITED: Zwaan, F., Brune, S., Glerum, A.C., Vasey, D.A., Naliboff, J.B., Manatschal, G., Gaucher, E.C (in press). Rift-inversion orogens are potential hotspots for natural H2 generation. Science Advances. Link to preprint: https://doi.org/10.21203/rs.3.rs-3367317/v