A team of researchers from the University of Oxford, Durham University, and the University of Toronto has identified the key geological factors necessary for locating clean, naturally occurring hydrogen resources beneath the Earth's surface. The study was published in the journal Nature Reviews Earth & Environment.
Abandoned water well, Montana, USA. Measurement of gases dissolved in groundwater may help discover natural hydrogen. Image Credit: Chris Ballentine
The study outlines the conditions required for the accumulation of natural hydrogen, generated by Earth over geological timescales, within the crust. Notably, the research highlights that geological environments possessing these necessary ingredients are found extensively across the world.
Hydrogen is a significant $135 billion industry, crucial for producing fertilizers and other vital industrial chemicals. It also represents a critical clean energy source for future low-carbon technologies, with a projected market value of up to $1 trillion by 2050.
These findings offer a potential solution to the challenges of hydrogen supply. They provide a roadmap for the industry to locate and extract natural hydrogen to meet global demand, potentially eliminating the reliance on hydrocarbons for this purpose.
A dependable source of hydrogen gas is crucial for societal operations. Hydrogen-derived fertilizers support food production for half of the world's population, and hydrogen is also a pivotal energy carrier in numerous plans for a carbon-neutral future, essential for mitigating the most severe climate change forecasts.
Hydrogen production relies on hydrocarbons, with the resulting waste gases contributing to 2.4% of global CO2 emissions. The demand for hydrogen is projected to rise from 90 million tons in 2022 to 540 million tons by 2050, making it imperative that future hydrogen production is free of CO2 emissions. Production combined with carbon capture and storage or renewable energy sources like wind and solar are potential future hydrogen sources, but are not yet economically competitive.
The research indicates that the Earth's continental crust has naturally produced a vast amount of hydrogen gas over the last billion years—enough to satisfy human energy needs for at least 170,000 years. Despite some losses and current inaccessibility, the remaining natural hydrogen could serve as a clean, emission-free energy source.
Limited historical data on hydrogen sampling and measurement have hampered scientists' understanding of the location and quantity of hydrogen within the Earth's crust. Developing an exploration strategy is therefore essential to locate accessible and commercially viable deposits of natural geological hydrogen.
We have successfully developed an exploration strategy for helium and a similar ‘first principles’ approach can be taken for hydrogen.
Jon Gluyas, Study Co-Author and Professor, Durham University
The study details the essential factors for developing an exploration strategy aimed at identifying various 'hydrogen systems. This encompasses understanding the quantity of hydrogen generated and the specific rock types and conditions under which this occurs, the mechanisms by which hydrogen migrates underground from these source rocks, the geological conditions that facilitate the formation of a hydrogen gas field, and the processes that lead to the depletion or destruction of hydrogen.
The authors identify areas where our understanding of these key factors is robust, while also pointing out areas requiring further investigation—such as the efficiency of rock reactions and how geological processes bring the necessary rocks and water together for these reactions to occur.
While some potential hydrogen sources, like those originating from the Earth's mantle, have been the subject of much speculation and exaggeration, this research indicates that they are not practical sources. Instead, the authors demonstrate that the components for a complete hydrogen system can be found in a variety of common geological environments within the Earth's crust. Some of these systems can be relatively young, forming hydrogen in recent geological time (millions to tens of millions of years), while others are truly ancient (hundreds of millions of years old)—but crucially, they are found globally.
Combining the ingredients to find accumulated hydrogen in any of these settings can be likened to cooking a soufflé – get any one of the ingredients, amounts, timing, or temperature wrong and you will be disappointed. One successful exploration recipe that is repeatable will unlock a commercially competitive, low-carbon hydrogen source that would significantly contribute to the energy transition – we have the right experience to combine these ingredients and find that recipe.
Chris Ballentine, Study Lead Author and Professor, Department of Earth Sciences, University of Oxford
The significant potential of naturally occurring geological hydrogen has inspired the authors to establish Snowfox Discovery Ltd., an exploration company dedicated to locating commercially viable accumulations of this natural resource.
Journal Reference:
Gluyas, J., et al. (2025) Natural hydrogen resource accumulation in the continental crust. Nature Reviews Earth & Environment. doi.org/10.1038/s43017-025-00670-1