By Denis Koshelev 

 

The growing urgency around climate change has pushed countries and industries worldwide to search for cleaner, more sustainable energy sources. Among the many options being explored, hydrogen has stood out as a strong candidate, with the potential to help decarbonize major parts of the global economy. But when it comes to how hydrogen is produced — specifically through green and blue methods — heated debates continue over their true environmental and practical merits.

 

There’s never been a more pressing time to shift toward a low-carbon global energy system. The Intergovernmental Panel on Climate Change (IPCC) warns that we’re on track to exceed 1.5°C of global warming above pre-industrial levels this century. [1] Against this backdrop, hydrogen has drawn increased interest as a flexible, powerful energy source, especially for sectors that are tough to electrify — like heavy industry and long-haul transport.

 

Hydrogen is On The Rise

 

Demand for hydrogen is going up. In 2023, global hydrogen use hit 97 million tonnes (Mt), marking a 2.5% increase over the previous year. [2] But even with this rise, hydrogen is still mostly being used in traditional areas like oil refining and chemical production, with limited expansion into newer sectors. [2] Right now, Asia leads in hydrogen production capacity with 43.3%, followed by Europe (26.8%) and the USA (26.2%). In Canada, production is highly regional, with Alberta and British Columbia at the forefront, and some notable activity in Ontario and Quebec. [10] Canada produces about 3 million tonnes annually, putting it among the world’s top ten producers. [11]

 

Still, hydrogen’s potential as a climate-friendly fuel is far from being realized. In 2023, low-emissions hydrogen made up less than 1% of global production, and its year-over-year growth was just 6%. This sharp contrast between traditional and cleaner methods of hydrogen production shows how much still needs to change for hydrogen to truly help combat climate change.

 

Hydrogen production tech has come a long way in recent years. Before 2015, alkaline water electrolysis dominated. But by 2016, polymer electrolyte membrane (PEM) electrolyzers started leading the way. That said, alkaline systems still have a 22% edge in production capacity, highlighting the ongoing competition between these technologies. [3]

 

Green vs. Blue Hydrogen: What’s the Difference?

 

Hydrogen can be produced in different ways, and not all of them are created equal when it comes to the environment. The biggest debate is between green and blue hydrogen, which vary widely in how they’re made and their impact on the planet. These differences really matter when we talk about hydrogen’s role in fighting climate change.

 

Green Hydrogen: Clean Power at a Cost

 

Green hydrogen is created by splitting water into hydrogen and oxygen through electrolysis powered by renewable energy, like wind, solar, or even nuclear. [4]

 

This method produces little to no direct carbon emissions. Life cycle assessments (LCAs) show that green hydrogen has a significantly smaller environmental footprint than other types, with average emissions around 2.02 kgCO₂eq per kilogram of hydrogen. [5]

 

The environmental benefits of green hydrogen are hard to ignore. Some studies suggest it can cut global warming impacts by as much as 66–95% when combined with other clean energy strategies. [6] With water vapour and heat as its main byproducts, it’s about as clean as it gets. [18]

 

But those benefits depend heavily on where the renewable energy comes from — and there are some downsides. One of the biggest concerns is water usage. Electrolysis needs a lot of water, which could be a problem in regions already facing shortages. Desalinating seawater helps, but it brings its own issues, like dumping salty brine into oceans and ecosystems.

 

Plus, green hydrogen often ties into ammonia and methanol production, which come with their own waste streams. These processes rely on chemical catalysts that can be toxic. If they’re not handled carefully, they can pollute water and soil. [19] On top of that, hydrogen is an indirect greenhouse gas. Leaks during production or storage can weaken its climate benefits. Even though green hydrogen cuts warming by more than 60% compared to fossil fuels, leaks — especially early on — could chip away at those gains. [20]

 

Blue Hydrogen: Fossil Fuels with Carbon Capture

 

Blue hydrogen comes from natural gas. Carbon emissions from the process are captured and stored, making it less polluting than traditional methods — at least in theory. [4]

 

When done right, with high CO₂ capture rates (about 93%) and low methane leakage, blue hydrogen can cut emissions significantly compared to regular natural gas use. [7]

 

Blue hydrogen is often seen as a bridge solution—cheaper to make than green hydrogen and easier to scale using existing infrastructure. But it’s still fossil fuel-based, and that comes with major drawbacks. Carbon capture isn’t perfect, methane can still leak, and relying on natural gas delays the shift to truly clean energy. [12][13] A 2021 study by academics from Cornell and Stanford universities labelled blue hydrogen, even with carbon capture, a “distraction” from genuinely sustainable hydrogen production. [14]

 

So, Is the Future Green or Blue?

 

Hydrogen is expected to play a major role in the global shift to cleaner energy — especially in areas like steelmaking, shipping, and chemical manufacturing, where electricity alone might not cut it. [15][16]

 

Choosing between green and blue hydrogen isn’t simple. It depends on cost, scalability, carbon emissions, infrastructure, and how fast we can make the switch. Today, blue hydrogen tends to be cheaper thanks to existing natural gas systems and lower upfront costs. [8] But that’s changing fast. As technology improves and renewable energy gets even cheaper, green hydrogen costs are expected to drop sharply. [9] 

 

By 2050, experts say green hydrogen could make up 50–65% of global supply, while blue hydrogen might account for 20–35%, mainly in regions with cheap natural gas and strong carbon capture capabilities, like North America and the Middle East. [17]

 

So, will green hydrogen take the lead? It’s likely — but only if we can cut production costs, expand renewable power, and build the infrastructure to support it. As demand for clean hydrogen grows, grey hydrogen — the dirtier version — will likely fade. [17] Of course, green hydrogen is not a universal solution or the only “future” of energy. However, it is poised to become a vital part of the clean energy mix.

 

References

1. https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2024/Jul/IRENA_Green_hydrogen_strategy_design_2024.pdf

2. https://www.iea.org/energy-system/low-emission-fuels/hydrogen

3. Paraschiv, S., Paraschiv, L., & Serban, A. (n.d.). Global hydrogen production capacity for sustainable decarbonization and green transition in transport applications to mitigate climate change: A comprehensive overview.

4. Mahmoud Hamed, Tengku Nordayana Akma Tuan Kamaruddin, Nabilah Ramli, Mohd Firdaus Abdul Wahab (2023). A review on blue and green hydrogen production process and their life cycle assessments.

5. Maniscalco, M. P., Longo, S., Cellura, M., Miccichè, G., & Ferraro, M. (2024). Critical review of life cycle assessment of hydrogen production pathways.

6. Elegbeleye, I., Oguntona, O., & Elegbeleye, F. (2025). Green hydrogen: Pathway to net zero greenhouse gas emission and global climate change mitigation. 

7. Bauer, C., Treyer, K., Antonini, C., Bergerson, J., Gazzani, M., Gencer, E., Gibbins, J., Mazzotti, M., McCoy, S. T., McKenna, R., Pietzcker, R., Ravikumar, A. P., Romano, M. C., Ueckerdt, F., Vente, J., & van der Spek, M. (2021). On the climate impacts of blue hydrogen production.

8. https://montel.energy/resources/blog/blue-hydrogen-vs-green-hydrogen

9. https://fin-wiser.com/2024/02/22/hydrogen-production-a-cost-analysis-of-blue-vs-green-methods/

10. https://natural-resources.canada.ca/energy-sources/clean-fuels/hydrogen-strategy/hydrogen-strategy-canada-progress-report

11. Hydrogen Factsheet - Canada Prepared by Jens Honnen, Jakob Eckardt, Raffaele Piria (adelphi): https://adelphi.de/system/files/mediathek/bilder/H2%20Factsheet%20Canada_July%202022_publication_final_v2.pdf

12. https://montel.energy/blog/blue-hydrogen-vs-green-hydrogen

13. https://www.gevernova.com/gas-power/resources/articles/2024/green-vs-blue-hydrogen_whats-the-difference

14. https://www.rechargenews.com/energy-transition/blue-hydrogen-worse-than-gas-for-the-climate-landmark-studys-damning-verdict/2-1-1051084

15. https://www.cnn.com/2021/08/28/world/green-hydrogen-climate-explainer-blue-gray-intl-cmd

16. https://www.iea.org/reports/the-future-of-hydrogen

17. https://www.mckinsey.com/industries/oil-and-gas/our-insights/global-energy-perspective-2023-hydrogen-outlook

18. https://www.worldwildlife.org/stories/what-is-green-hydrogen-and-how-can-it-help-tackle-the-climate-crisis

19. https://blogs.iadb.org/sostenibilidad/en/key-aspects-for-managing-the-environmental-and-social-risks-of-green-hydrogen/

20. Sun, T., Shrestha, E., Hamburg, S. P., Kupers, R., & Ocko, I. B. (2024). Climate impacts of hydrogen and methane emissions can considerably reduce the climate benefits across key hydrogen use cases and time scales.