A new study led by the University of Sheffield has cautioned that the global shift towards green hydrogen may not deliver the expected climate benefits unless major changes are made in how hydrogen is produced and transported, Businessworld reported.
Published in the journal Nature Communications Sustainability, the research says the environmental impact of hydrogen varies widely depending on the energy sources used across its supply chain. Although green hydrogen is being promoted as a solution to cut emissions in sectors such as steel, chemicals and heavy transport, the study warns that its climate advantage can be reduced if production depends on electricity generated from fossil fuels.
The researchers examined 20 possible hydrogen production and transport scenarios across 14 countries between 2023 and 2050. The countries studied include the United States, United Kingdom, Germany, Japan and China. Five different production methods were assessed, including electrolysis and biomass-based processes, along with the effect of transport systems on overall emissions.
The findings show that hydrogen produced through electrolysis currently has among the highest global warming impacts because much of the electricity used in the process comes from carbon-intensive power grids. At present, about 96 per cent of global hydrogen production remains linked to fossil fuel-based energy systems, raising concerns over whether expanding hydrogen use will automatically cut emissions.
However, the study notes that hydrogen could become much cleaner if electricity systems shift rapidly towards renewable energy. By 2050, some hydrogen supply chains could lower environmental impacts by more than 90 per cent compared with current levels, if renewable electricity becomes the main power source.
The researchers also highlight the role international supply chains could play. One scenario suggests that hydrogen produced in the United Kingdom using proton exchange membrane electrolysis and exported to the United States could achieve significantly lower environmental impacts, provided both countries move to cleaner power systems.
