Scientists are warning that hydrogen fuel could make climate change worse. 

The world’s desperate search for a climate-friendly fuel has landed on hydrogen. Efforts are occurring around the world to use it as a new fuel for factories, buildings, ships and planes without pumping carbon dioxide into the sky.

But scientists warn that hydrogen leaked into the atmosphere contributes to climate change much like carbon. In fact, it could even make warming worse over the next few decades, depending on how it is made, distributed and used. 

“The potency is a lot stronger than people realise,” says Ilissa Ocko, a climate scientist with the non-profit Environmental Defence Fund. 

“We’re putting this on everyone’s radar now not to say ‘no’ to hydrogen but to think about how we deploy it.”

Hydrogen does not trap heat the way CO₂ does. However, it can set off a series of chemical reactions that warm the air when it is released, acting as an indirect greenhouse gas. 

Although it cycles out of the atmosphere faster than carbon dioxide, it can do more damage than CO₂ in the short term. 

Over 20 years, hydrogen has 33 times the global warming potential of an equal amount of carbon dioxide, according to some estimates.

With governments worldwide investing billions to build a hydrogen economy, this issue is becoming more significant. 

Researchers say that the risks are not a reason to give up on hydrogen, but they must be accounted for in any future system for producing, distributing and using the gas. 

Preventing leaks will be fundamental to the climate-friendliness for these systems. This is especially true for the utility companies experimenting with blending hydrogen into their existing natural gas pipelines, as a hydrogen economy riddled with leaks would undercut its own effectiveness.

“We’re at risk of proceeding with the build-out of new infrastructure that’s essentially going to repeat all those past harms,” says Julie McNamara, deputy policy director for climate and energy with the Union of Concerned Scientists. 

“We don’t have the time or luxury to get it wrong.”