Water, as we all know, is the most precious of resources here on planet Earth. On the most fundamental level, it sustains all life. But it also serves a myriad of crucial purposes that make it indispensable to human civilisation, including cooking, sanitation, cleaning, irrigation of crops, aquaculture, transportation…the list goes on. And, of course, it is an essential resource for the industrial and energy sectors.
This year, World Water Day took place on 22 March, and its key theme was ‘Glacier Preservation’. The theme is timely, with a recent study published in the journal Nature noting that the world’s glaciers are melting faster than ever recorded.1 In the most comprehensive scientific analysis carried out to date, it was discovered that over the past decade or so, glacier losses were more than a third higher than during the period 2000 – 2011.
Glacier preservation is seen as a top priority as the world works to mitigate and adapt to climate change. And the reduction of greenhouse gas emissions is essential to decelerate glacial retreat.
Step forward clean energy technologies. Blue and green hydrogen are widely regarded as having a key role to play in decarbonising our economy and achieving net zero emissions. However, there is, of course, no perfect solution to the challenge of climate change, and it is important to acknowledge that hydrogen does have an indirect influence on atmospheric warming. Research has suggested that the global warming potential (GWP) of hydrogen over a 100-year time horizon is 11 ± 5, which is significantly more than previous estimates.2 According to DNV, the climate benefits of hydrogen are still clear, since co-emitted combustion species (such as carbon monoxide, methane, and VOCs) are also reduced. However, in light of hydrogen’s indirect GWP, efforts should also be made to reduce leakage during production, storage, transportation, and use.3
And this brings us back to the issue of water. While hydrogen has the potential to help reduce the speed of glacial melting by lowering greenhouse gas emissions into the atmosphere, all hydrogen production technologies require significant quantities of water for production and cooling. A 2023 study by the International Renewable Energy Agency (IRENA) and Bluerisk attempted to shed some light on the extent to which water is required.4 Its findings suggest that green hydrogen is the most water efficient of all clean hydrogen types. In terms of water use as a cooling medium, blue hydrogen production is the most intensive, due to the significant water requirements of CCUS systems for heat transfer. Amongst its recommendations, the report suggests that green hydrogen projects should be prioritised for future development, in order to reduce exposure to future water-shortage-related risks. Other recommendations include increased investment and research to reduce the consumption of freshwater for cooling, and incentivising the use of seawater for hydrogen production and cooling in freshwater-stressed coastal areas.
In this issue of Global Hydrogen Review, Kurita considers the challenges of offshore seawater desalination for use in hydrogen production, and explains why it is a clear and viable option for green hydrogen projects wishing to take advantage of readily available wind energy and practically limitless water supply (p. 33). Meanwhile, EnviroChemie GmbH consider the use of industrial wastewater as an alternative source for bridging the gap between limited water availability and potential growth of green hydrogen production (p. 39).
- ‘Community estimate of global glacier mass changes from 2000 to 2023’, Nature, (19 February 2025).
- WARWICK, N., GRIFFITHS, P., KEEBLE, J., ARCHIBALD, A., PYLE, J., and SHINE, K., ‘Atmospheric implications of increased hydrogen use’, (April 2022).
- MAPLE, M., ‘Is hydrogen a greenhouse gas?’, DNV, (5 November 2023).
- ‘Water for hydrogen production’, IRENA and Bluerisk, (December 2023).
