Annual greenhouse gas emissions from unabated fossil-fuel hydrogen production are on a par with those from the aviation industry, so it would make more sense for the world to focus on decarbonising existing H2 uses rather than long-term problems such as flying, according to one of the founders of the Hydrogen Science Coalition.

Tom Baxter, a senior lecturer at the University of Aberdeen, who spent more than four decades working as an oil & gas engineer, looked at aviation emissions data from the International Council on Clean Transportation (ICCT), and realised they were very close to those emitted annually by existing grey hydrogen production from natural gas and coal.

In 2019, 920 million tonnes of CO2 were emitted by the aviation industry globally, according to the ICCT, compared to about 850 million tonnes from hydrogen producers.

“Indeed, if hydrogen production methane emissions from the supply are included [the H2 figure in terms of CO2-equivalent] would be significantly higher,” Baxter wrote in a LinkedIn post.

“I find it surprising that current unabated hydrogen production receives so little attention in comparison to aviation. Many proposed low-carbon hydrogen schemes do not address current hydrogen production and elect to use low-carbon hydrogen for heat and power. Surely our first actions should be to decarbonise current highly polluting hydrogen production?”

About 70-75 million tonnes of grey hydrogen — often referred to as black or brown H2 when derived from coal or lignite — is produced each year, with most of that used for ammonia fertiliser production, oil refining and in the wider chemical industry.

“Of course it is important that all GHG [greenhouse gas] emitting sectors are addressed. But it is also important to prioritise the focus on the sectors that we can make short-term material GHG reduction gains as the coming decade is vital for checking global warming,” Baxter added.

“In my view, aviation is not a short-term target and it is currently receiving too much attention with respect to the benefits that can be achieved.”