Truly clean hydrogen is desperately needed: Will an ISO Standard help or hinder its climate potential?

By Morgan Rote, Pete Budden and Joe Williams

• The first international hydrogen standard is poised to shape national hydrogen policies, but in its current form it overlooks critical science on electricity sourcing, methane leakage and hydrogen’s own warming impacts — risking the credibility of clean hydrogen as a true climate solution.
• To ensure hydrogen delivers real climate benefits and advances COP30’s clean energy transition goals, the hydrogen standard should include robust, science-based guardrails.

This November, policymakers from around the world will be gathering in Brazil to chart the course of global climate action for the next 10 years. First on the Action Agenda is “accelerating zero- and low-emission technologies in hard-to-abate sectors.” In other words: hydrogen and other clean fuels that could help the world transition away from fossil fuels. But the extent to which hydrogen actually helps achieve this key COP30 clean energy transition objective depends heavily on the greenhouse gas emissions standards put into place to ensure its climate benefits.

Truly clean hydrogen is a crucial climate solution for some of the trickiest polluting sectors. Steel, ships and planes, which rely on fossil fuels and have a hard time directly electrifying, could instead be fueled by clean hydrogen or its derivatives (ammonia, methanol, etc.). But the climate impact of hydrogen varies greatly depending on how it is produced and managed. If it is produced from fossil-fueled electricity or by diverting existing renewables it can end up being worse for the climate than the fossil fuels it is replacing. Failure to limit methane leakage and capture CO2 when producing hydrogen from fossil fuels is also a major problem, as is leakage of hydrogen itself.

Right now, the first international standards for hydrogen are being developed by the International Organization for Standardization. While the Draft International Standard on hydrogen production has made some real improvements relative to the starting point, it still falls short of what’s needed to provide a rigorous underpinning for the global clean hydrogen industry — and is unlikely to reach that mark by the time it’s presented ahead of COP30 in Belém.

What is the ISO standard and why does it matter?

ISO is a well-known federation made up of national standards bodies — organizations from different countries — established to create sets of global standards, which are then widely accepted as best practice in different industries, from occupational health and safety to medical device regulation. And for the last two years, ISO has been working on a new standard that sets the methodology for calculating GHG emissions associated with hydrogen production.

This standard matters for several reasons. It’s important to have a globally agreed-upon way of counting emissions — this allows, for example, Japan to know that it’s importing a clean form of hydrogen or ammonia from an American producer; an IMO member state to know it’s meeting clean fuel targets; and a country like Brazil to know whether hydrogen fits into its net-zero plans.

This particular standard will likely be influential for national policymaking around the world. While the U.S., UK and EU have already set their own standards, countries like India, Indonesia, Japan and Brazil have all referenced an intent to incorporate the ISO standard into their own national hydrogen policies.

However, widespread adoption of this standard in its current form would be problematic. It does not represent a comprehensive accounting of GHG impacts and ignores much of the latest scientific research on emissions. Policymakers cannot merely replicate it in their H2 standards – they will have to supplement it with their own set of science-based guardrails.

The missing science in the ISO hydrogen standard

The hydrogen standard still ignores the latest science on several fronts.

First, it overlooks the range of emissions impacts associated with electricity use

For electrolyzers claiming to be running on renewable power, three key factors greatly affect the level of emissions: where the electricity is sourced from, whether it was available during the hour of use, and whether or not it would have already served some other use. If these factors are not accounted for, renewable hydrogen could actually increase climate warming.

The impact of these three factors is widely acknowledged, and elements have been incorporated into U.S., EU and UK standards for hydrogen. For example, the EU requires renewable hydrogen — including imports from other countries — to meet guardrails on all three factors to meet its regulatory definition and be eligible for subsidies.

These factors are also under consideration for electricity accounting more widely in various highly impactful accountability frameworks, including the GHG Protocol, SBTi and even ISO’s own general carbon footprint standard working group.

Yet the ISO hydrogen standard fails to require such reporting or describe why such metrics matter for emissions. This means that products following the ISO standard wouldn’t have to declare whether or not they have complied with these metrics, making their carbon footprint declaration meaningless, particularly in markets like the EU.

Second, it permits undercounting of upstream methane emissions

Upstream methane leakage represents one of the largest contributors to the climate impact of fossil-based hydrogen, and leakage rates vary widely by geography and operator. High-quality data on emission rates is now available; the UN-run International Methane Observatory offers a platform for basin-specific methane emissions rates, and the 140 plus members of the Oil and Gas Membership Partnership 2.0 have committed to strong verification practices for company-specific estimates.

Yet the ISO standard maintains the option to revert to national average leak rates, which have been widely found to underestimate compared to real measurements.

Third, it ignores hydrogen’s indirect warming potential

If hydrogen is not properly managed, fugitive or operational emissions can create a significant indirect warming impact by increasing the concentration of other greenhouse gases in the atmosphere. This risk has been documented by the IPCC, along with multiple international teams of scientists and the IPHE. We now estimate that every 1% of hydrogen emitted can reduce hydrogen systems’ climate benefits by about 3% in the near term.

Some geographies are proactively tackling this issue — namely the EU and UK, which are both actively involved in this body of research, have tasked their pipeline regulators and hydrogen operators respectively with leak prevention and alluded to future emissions quantification. Yet the current ISO methodology still treats hydrogen loss as harmless waste, rather than the potent climate warmer that it is.

What needs to be done?

ISO has a responsibility to reflect the latest climate science and best practices for emissions accounting. As its working group members acknowledge, this standard is designed to be a comprehensive resource for countries, able to inform hydrogen policies regardless of their own capacity or level of expertise on the subject. By failing to document climate impacts or promote transparency, ISO will fail its members and the broader hydrogen economy.

It is time to correct course.

ISO should immediately open a revision process to correct these oversights. In the meantime, policymakers must recognize the shortcomings of this standard and supplement it with their own sets of science-based guardrails.

The integrity of the hydrogen industry — the extent to which it helps meet COP30 climate objectives — is what’s at stake.

If you will be in New York next week, we invite you to join us for our session on the emissions accounting standards needed to ensure real climate benefits. Click here for more information and to register.