Hydrogen, the so-called ‘fuel of the future’, is coming. The European Green Deal and subsequent RepowerEU communication has given hydrogen a central role in Europe’s energy transition. Both public and private investments in hydrogen worldwide are growing. The European Commission predicts that by 2050, €470 billion will be invested in European hydrogen projects.

With all of the excitement and discussion around new climate solutions, the Environmental Defense Fund has published a study warning that hydrogen is a leak-prone gas with a potent warming effect that is widely overlooked, even by experts.

While it has the potential to be a clean fuel, it also runs the risk of being an indirect climate pollutant, as it easily leaks into the atmosphere. Our research suggests that, when done correctly, hydrogen can have near-zero climate impacts - but done incorrectly, it could be worse, in the near-term, than the fossil fuels it’s intended to replace. Whether hydrogen turns out to be a climate Jekyll or Hyde will depend both on how it’s made and how much of it leaks.

Hydrogen is an indirect greenhouse gas. It doesn’t trap heat, but, through a series of chemical reactions, it increases the amount of greenhouse gases like methane, which is accelerating the rate of global warming. Hydrogen’s effects on the climate are short-lived but potent, say EDF scientists Steven Hamburg and Ilissa Ocko, co-authors of the new study. “If we overlook near-term climate impacts,” says Ocko, “we risk more climate damage during our lifetimes. Addressing them is going to help us today as well as the generations of tomorrow.”

According to EDF’s research, if hydrogen has a high leak rate, and it’s produced from natural gas with a high methane leak rate, then replacing fossil fuels with hydrogen could increase warming for several decades. On the other hand, if it’s produced using renewable energy and water and leak rates are minimal, switching to hydrogen could nearly eliminate the warming impacts from fossil fuels.

We have a lot more to learn about hydrogen before it can deliver on its promise, but this much is clear: hydrogen’s value in addressing the climate crisis depends on where it is used, how it’s produced and if leakage is minimised. The industry is in its infancy and now is the time to make sure we address these concerns — not after we’ve built out the system.

Read EDF’s Climate consequences of hydrogen emissions