Steelworker working with very hot materials, amidst sparks.

A steel mill’s blast furnace: Hydrogen holds promise to reduce carbon emissions from steel manufacturing and in many other sectors.

Clean or dirty: Is hydrogen the climate-friendly energy solution we need?

Hydrogen holds tremendous potential for reducing greenhouse gas emissions and combating climate change. Policymakers and industry are pouring hundreds of billions of dollars into various hydrogen energy technologies.

But hydrogen is a leak-prone gas with a potent warming effect of its own that is widely overlooked. Whether a hydrogen energy revolution helps the climate will depend on how it’s produced, managed and used.

While hydrogen is mainly used today in fertilizer production and oil refining, supporters envision it everywhere from transportation fuel to home heating and cooking, and augmenting wind and solar generation.

But measures are needed to keep hydrogen from escaping into the atmosphere.

And even when leaks are minimal, hydrogen won’t be the best choice for every application. For needs like powering cars and heating homes, clean electricity from renewable sources will often be cheaper and better for the climate than hydrogen.

Newly recognized warming power

Scientists have long known that hydrogen triggers indirect warming effects in the atmosphere. But researchers from EDF and elsewhere say its warming power is much greater than previously recognized.

What’s more, standard scientific accounting used in international climate treaties and reporting requirements systematically understate hydrogen’s powerful near-term warming effects.

Climate impacts are nearly always calculated over a 100-year timeframe. But hydrogen doesn’t remain in the atmosphere for long, and its warming effects disappear after about two decades. This accounting mismatch masks damage caused by escaped hydrogen in the near term.

Recent research provides a clearer picture of hydrogen’s near-term climate impacts, finding it has eight times more warming power when measured over a 20-year period than was generally recognized just a few years ago.

That means it is critical to keep hydrogen from escaping. And as the smallest molecule, hydrogen is particularly difficult to contain.

Take action. Help ensure that hydrogen benefits the climate fight.

What is “clean” hydrogen?

Hydrogen is typically produced using fossil fuels, through energy-intensive processes that result in a lot of climate pollution.

But hydrogen can also be made using renewable energy to split water molecules into hydrogen and oxygen (“green” hydrogen), or by extracting it from natural gas under conditions in which most carbon dioxide emissions are captured and stored (“blue” hydrogen).

Neither blue nor green hydrogen is available at scale yet, but massive investments are now flowing into the sector and are expected to change that.

Made, managed and used properly, hydrogen could bring real climate benefits. But if too much hydrogen escapes, those emissions could reduce the climate benefits relative to fossil energy — especially in the near-term.

Benefits depend on leakage

In a groundbreaking 2022 study, EDF scientists explained how unchecked hydrogen emissions can undercut the climate benefit of moving from fossil fuels to hydrogen.

Switching to hydrogen could nearly eliminate the warming impacts from fossil fuels — if the hydrogen is made using renewable energy (that is not diverted from what is needed for the power grid), and strong measures are in place to prevent hydrogen leaks and other emissions.

But if lots of hydrogen enters the atmosphere through leaks and intentional releases known as venting and purging, that would dramatically reduce the climate benefits of even the cleanest hydrogen systems.

And in cases where hydrogen is produced from natural gas with high emissions of both hydrogen and methane — the main ingredient of natural gas — the 20-year warming impact of the hydrogen systems could be higher than that of fossil fuel systems. (Methane is a potent climate pollutant.)

Explore EDF research on the climate consequences of hydrogen

How hydrogen is used also matters

Preventing hydrogen from leaking into the atmosphere will be crucial. And use-case also matters.

Hydrogen is most appropriately used for applications where other clean alternatives are lacking, such as steel and cement production, or as a chemical for making alternative fuels for ships and planes. And since transporting hydrogen is likely to increase the risk of leaks, it makes sense to produce it close to where it’s used.

Prior research suggests deployment of green hydrogen can require two to 14 times more energy than available alternatives that use direct electrification.

That means in most cases it won’t make sense to divert clean electricity from the grid to make hydrogen for use in cars, homes or commercial buildings, where clean electricity can serve these energy needs directly.

Take action. Help ensure that hydrogen benefits the climate fight.

Our hydrogen experts

We bring wide-ranging perspectives and skills to our work on hydrogen. Meet some of the people who make it happen.


Ciel Jolley

+32 2 622 98 43 (office)

+32 478 97 76 30 (mobile)