A new study has found that hydrogen made from fossil fuels could delay UK decarbonisation.

Researchers from Cornell and Stanford universities found that blue hydrogen, produced with carbon capture and storage, could be 20% worse for the climate than burning natural gas or coal for heat.

They said the focus should be on green hydrogen – made from water using renewable energy.

The study, published today by Energy Science and Engineering journal, raises questions about UK government plans to use blue hydrogen to replace fossil fuels and the proposed conversion of onshore gas sites to hydrogen production.

The academics have suggested blue hydrogen needs large amounts of natural gas and, even with the most advanced carbon capture and storage technology, there would be “a significant amount of the carbon dioxide and methane emissions that won’t be caught”.

They said blue hydrogen had “no role in a carbon-free future”. It was a “distraction” that could “divert focus away from genuinely green technologies”, they said.

Blue hydrogen is a key part of the UK government’s energy transition plans. There are major CCS projects proposed for northern England involving large oil and gas companies.

A government spokesperson said:

“Independent reports, including that from the Climate Change Committee, show that a combination of blue and green hydrogen is consistent with reaching net zero but alongside the strategy, we will consult on a new UK standard for low-carbon hydrogen production to ensure the technologies we support make a real contribution to our goals.”

But a co-author of the study, Professor Robert Howarth, of Cornell University, said:

“Politicians around the world, from the UK and Canada to Australia and Japan, are placing expensive bets on blue hydrogen as a leading solution in the energy transition.

“Our research is the first in a peer-reviewed journal to lay out the significant lifecycle emissions intensity of blue hydrogen. This is a warning signal to governments that the only ‘clean’ hydrogen they should invest public funds in is truly net-zero, green hydrogen made from wind and solar energy.”

The study found that the carbon emissions of blue hydrogen were barely better than grey hydrogen made using unabated gas.

And the fugitive methane emissions for blue hydrogen were higher than for grey hydrogen because of an increased use of natural gas to power the carbon capture.

The authors said:

“Perhaps surprisingly, the greenhouse gas footprint of blue hydrogen is more than 20% greater than burning natural gas or coal for heat and some 60% greater than burning diesel oil for heat.”

They added:

“Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption. Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.

“There really is no role for blue hydrogen in a carbon-free future. We suggest that blue hydrogen is best viewed as a distraction, something that may delay needed action to truly decarbonise the global energy economy.”

• The UK government is expected to publish its hydrogen strategy next month. The Cornell/Stamford study supports arguments made by the Weald Action Group about fossil hydrogen.

Ruth Hayhurst will be sending reports for DrillOrDrop from the COP26 conference in Glasgow in November .