CLIMATE ambitions are high as we march steadily towards the COP26 conference in Glasgow later this year, and “blue hydrogen” features highly in the UK Government’s plans to reach net zero by 2050.

The European Commission also sees hydrogen as a “key priority” in achieving Europe’s transition to clean energy.

However, scientists in the US have reported that producing and using hydrogen could be as much as 20% worse for the climate than using natural gas.

Hydrogen is abundant and can be sourced from natural gas or water, but energy is needed during the sourcing process.

That made from natural gas incorporates carbon capture, utilisation and storage (CCUS) to be low-carbon, making what is usually known as “blue hydrogen”.

The procedure of sourcing it from water through electrolysis has to be powered by a low-carbon source of energy – such as that from renewables – to be a low-carbon process and to make “green hydrogen”.

“Blue hydrogen” is extracted from methane in natural gas, but academics at Cornell and Stanford universities have found its production and use in industry and homes could be up to 20% worse for the climate than using natural gas because of the emissions that occur when gas is extracted from the ground to produce it.

The National:

Dr Robert Howarth, above, a biogeochemist and ecosystem scientist at Cornell University, and Professor Mark Jacobson, director of Stanford University’s atmosphere/energy programme, said theirs was the first effort to examine the lifecycle greenhouse gas emissions of blue hydrogen – accounting for emissions of carbon dioxide and unburned “fugitive” methane.

In their paper, to be published in the journal Energy Science & Engineering, they said: “Far from being low carbon, greenhouse gas emissions from the production of blue hydrogen are quite high, particularly due to the release of fugitive methane.

“For our default assumptions (3.5% emission rate of methane from natural gas and a 20-year global warming potential), total carbon dioxide equivalent emissions for blue hydrogen are only 9-12% less than for grey hydrogen [that produced using fossil fuels].”

The researchers continued: “While carbon dioxide emissions are lower, fugitive methane emissions for blue hydrogen are higher than for grey hydrogen because of an increased use of natural gas to power the carbon capture.

“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, again with our default assumptions.

“In a sensitivity analysis in which the methane emission rate from natural gas is reduced to a low value of 1.54%, greenhouse gas emissions from blue hydrogen are still greater than from simply burning natural gas, and are only 18-25% less than for grey hydrogen.”

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.”

Friends of the Earth said back in November that there was a lot of “hype” around hydrogen, especially amongst those who liked the idea of “technological fixes”.

However, the group added: “Hydrogen can be made using renewable energy and water, but the fossil fuel companies are pushing to produce it from natural gas.

“Producing hydrogen from natural gas is much dirtier, but unfortunately it looks like the Prime Minister is going to back it.”

The UK Government’s strategy for hydrogen is expected to be published next month, but it is seen as an essential part of its commitment to cutting greenhouse gas emissions.

A 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.”