Research
The goal of this programme is to understand the climate and air quality impacts of hydrogen-based energy systems.
Switching from fossil fuels to hydrogen can offer significant climate benefits when hydrogen is produced via low carbon methods. Hydrogen can serve as a clean energy carrier, reducing reliance on fossil fuels and lowering carbon dioxide emissions. However, when emitted into the atmosphere, hydrogen contributes to climate change by increasing the amounts of greenhouse gases such as methane, ozone and water vapour. Ozone is also an air pollutant due to its effects on people and the environment. This is a problem as fugitive hydrogen emissions emitted during the production, storage and distribution of hydrogen will offset some of the climate benefits from reductions in carbon dioxide emissions. Understanding and mitigating the complex interactions between hydrogen and other atmospheric constituents is crucial for leveraging hydrogen as a tool in combating climate change.
Our research focuses on determining the environmental implications of fugitive hydrogen emissions occurring through the large-scale distribution, storage and use of hydrogen.
Three independent projects will work together to assess H2 fugitive emissions, how H2 will be used, the impact of fugitive H2 emissions on atmospheric composition and climate, the air quality impacts of hydrogen-based energy systems and how much H2 is taken by soil microbes.
HECTER
Hydrogen’s impact on global and regional climate
HECTER will determine the impact of fugitive hydrogen emissions on global and regional climate using the UK Earth System Model (UKESM). Information on chemical uncertainties and radiative forcing derived from UKESM, along with new constraints on hydrogen soil uptake from ELGAR, will feed into a policy tool using the FaIR simple climate model. The FaIR policy tool will generate GWP100s and cumulative-CO2 benefits for any hydrogen emission scenario.
COSH-AIR
Future scenarios of hydrogen usage and the impact on air pollution
COSH-AIR will use the global and UK whole-economy energy system models, TIAM-UCL and UK TIMES, to create a suite of global and UK scenarios of future hydrogen energy system deployment. These scenarios will quantify the development of hydrogen infrastructure over the transition to Net Zero and estimate fugitive hydrogen emissions from the energy system.
Air quality and health implications of adopting hydrogen energy systems in the UK will be examined using the UK Integrated Assessment Model (UKIAM).
ELGAR
Hydrogen consumed by soil microbes
The aim of this project is to better understand the uptake of hydrogen by microbes in soils using a combination of laboratory-based experiments and field observations.
These measurements will enhance our knowledge of the amount of hydrogen consumed by soil microbes and how H2 uptake will respond to changes in land-use and climate. Understanding the amount of H2 consumed by microbes in soils, as opposed to undergoing chemical reactions in the atmosphere, is critical for understanding future climate feedbacks from fugitive hydrogen emissions.
The experimental findings will be synthesised into a process-based model for integration into global atmospheric H2 modelling systems.
Publications
- Brown, M. A. J., Warwick, N. J. and Archibald, A. T., (2025), Multi-model assessment of future hydrogen soil deposition and lifetime using CMIP6 data, Geophysical research Letters, 52.
- Bryant, H. and Stevenson, D. (2024), The influence of hydrogen on carbon monoxide in the troposphere. Weather, 79: 190-195.
- Bryant H. N., Stevenson D. S., Heal M. R. and Abraham N. L. (2024) Impacts of hydrogen on tropospheric ozone and methane and their modulation by atmospheric NOx. Front. Energy Res. 12:1415593. doi: 10.3389/fenrg.2024.1415593
- Cowan, N., Roberts, T., Hanlon, M., Bezanger, A., Toteva, G., Tweedie, A., Yeung, K., Deshpande, A., Levy, P., Skiba, U., Nemitz, E., and Drewer, J.: Quantifying the soil sink of atmospheric hydrogen: a full year of field measurements from grassland and forest soils in the UK, Biogeosciences, 22, 3449–3461, https://doi.org/10.5194/bg-22-3449-2025, 2025.
- Derwent, R. G., Jenkin, M. E., Stevenson, D. S., Utembe, S. R., Khan, A. H. and Shallcross, D. E., (2025), Influence of the oxidation of non-methane volatile organic compounds on tropospheric hydrogen: A STOCHEM-CRI global Lagrangian model study, Atmospheric Environment, 352.
- Tardito Chaudhri, A. K. and Stevenson, D. S., (2024), Soil Deposition of Atmospheric Hydrogen Constrained using Planetary Scale Observations, EGUsphere [preprint], (in press, Atmospheric Chemistry and Physics)