Fossil Fuel Derived Hydrogen Is Bad for Health and Worsens the Climate Crisis

Hydrogen is heavily marketed as a “clean” fuel, but most of the hydrogen produced in the US today is neither produced renewably nor derived from renewable sources.

  • 99% of hydrogen is derived from fossil fuels, mostly from methane, a fossil fuel intensive process that, according to Cornell and Stanford scientists, emits more greenhouse gases than diesel or coal.
  • The oil and gas industries claim that the fossil fuel pollution from producing hydrogen can be addressed through carbon capture and sequestration (CCS), but CCS also has serious drawbacks since it is also a fossil fuel intensive process

Furthermore, industry is proposing to blend hydrogen and natural gas (methane) for use in homes and buildings but this poses SERIOUS health, safety, and equity risks.

  • Burning hydrogen-methane blends increases nitrogen dioxide pollution and perpetuates reliance on fossil fuels
  • Hydrogen is highly flammable and increases the explosive potential of methane

Industry has also advocated for using green energy sources like wind and solar to make hydrogen for heating and cooking. There are two major drawbacks to this suggestion:

  1. Doing so uses a renewable technology that could be used directly; and
  2. Estimates of the amount of wind or solar to power even a small amount of hydrogen production suggest that this proposed approach is not viable.

In sum, the production and burning of fossil-fuel derived hydrogen is associated with large greenhouse gas emissions, which have significant negative consequences for health and are a known driver of climate disruption.

The Deep Dive: Why Fossil Fuel Derived Hydrogen Isn't Green

Fossil fuel-derived hydrogen (variously labeled as black, gray, blue or brown by marketers) is derived from methane and coal. It accounts for 99% of the hydrogen used in the United States.

Hydrogen made from water and renewable electricity is commonly referred to as “green” hydrogen and accounts for 1% of commercial use of the gas in the US. Understanding this distinction is critically important because there is great interest in marketing all hydrogen production as a “clean” alternative to natural gas.

While hydrogen is the most abundant element in the universe, it is predominantly found bonded to other molecules in chemical compounds like water and methane. Most hydrogen gas is produced by steam reformation, a process by which the hydrogen atoms are pulled off of methane (natural gas), which is composed of a single carbon atom with four hydrogen atoms attached. This process produces carbon dioxide emissions.

Burning hydrogen gas does not produce carbon dioxide, but it does produce the health harming air pollutant nitrogen dioxide.

Serious Risks to Health, Safety And Climate

The manufacture and use of fossil fuel derived hydrogen poses serious health risks, including (1) respiratory health harms (2) safety risks due to hydrogen’s explosive potential and (3) exacerbation of climate change. These risks all disproportionately affect vulnerable populations.

Risks to Respiratory Health

There is a significant risk to respiratory health due to air pollution created both through the production and burning of hydrogen; and through the burning of fuels composed of blended hydrogen and methane. The amount of nitrogen oxides (NOx) released can increase up to six-fold (compared with the burning of methane alone) as the amount of hydrogen is increased in a hydrogen-natural gas blend. Nitrogen oxides are a significant trigger for asthma and COPD exacerbations, and have been implicated as a likely cause of new asthma cases.

Blending Hydrogen and Methane Is Dangerous: Safety Risks Due to High Explosive Potential

Hydrogen is corrosive and highly combustible. It can ignite at almost any air-to-fuel ratio and is more explosive than methane gas. Moreover, adding hydrogen to natural gas would be expected to expand methane’s explosive limits. For this reason, piping the mix into homes and businesses carries the risk of explosion.

In addition, adding hydrogen to methane would make pipelines more brittle and increase the number and size of leaks. This would not only increase the risk of explosion but also increase the leakage of methane.

Massachusetts already has thousands of methane leaks across the state due to its aging natural gas infrastructure and lack of preventive maintenance. When methane leaks, so do the many air pollutants that travel with it, including benzene. Benzene is a volatile organic compound (pollutant) and known carcinogen associated with bone marrow suppression and leukemia.

Despite very high costs and the many health and safety risks of hydrogen, Massachusetts utility companies have requested authorization to mix hydrogen with methane, which the companies describe as a “renewable” and “fossil free” fuel source.

Klearly a bad idea. The film “ Glass Onion” suggests the dangers of using an untested and unsafe hydrogen technology that has been falsely advertised as suitable for domestic use. A house powered by “Klear,” a hydrogen-based fuel, has obvious safety issues as demonstrated by the dramatic explosion scene at the end of the movie.

Negative Climate Impact

When methane is used to produce hydrogen, the process emits carbon dioxide, an important driver of climate disruption. Even if carbon capture and storage (CCS) were utilized to make hydrogen, it has been estimated that the lifecycle greenhouse gas impact is more than 20 percent greater than burning methane gas or coal for heat and approximately 60 percent greater than burning diesel oil for heat, according to a recent article by Stanford and Cornell scientists in Energy Science Engineering. Their conclusion: fossil fuel derived hydrogen “is best viewed as a distraction, something that may delay needed action to truly decarbonize the global energy economy.”

In sum, the production and burning of hydrogen gas leads to carbon dioxide,  methane and nitrogen dioxide emissions. All three are potent greenhouse gases, key drivers of climate change.

Equity and Climate Justice

Blending hydrogen with methane will maintain a polluting infrastructure that harms communities of color disproportionately. Communities of color are already exposed to more air pollution from burning fossil fuels and they experience higher rates of air pollution related illnesses like asthma and COPD. Natural gas-hydrogen blends will be moved through current natural gas power plants and compressor stations, which are overwhelmingly situated amongst minority and/or low-income neighborhoods. Consequently, the increased air pollution generated and safety risks will disproportionately negatively impact the health of the most vulnerable communities.

In Sum: The Harms of Fossil Fuel Derived Hydrogen

While hydrogen is portrayed as a “carbon-free” fuel because it can be produced from renewable energy, only 1% is generated renewably. The other 99% is derived from fossil fuels, mostly methane. Increasing hydrogen production will therefore increase production of fossil-fuel derived hydrogen.

The burning of hydrogen doesn’t produce carbon dioxide emissions, but burning it does produce air pollution nonetheless, in the form of nitrogen dioxide, a respiratory irritant commonly known as smog. Production of hydrogen from fossil fuels increases carbon dioxide emissions since it is made from coal and methane.

Current proposals to use fossil fuel derived hydrogen will increase Massachusetts’ dependence on petrochemicals, worsen air pollution and exacerbate climate disruption. Proposals to blend hydrogen with methane (aka natural gas) perpetuate health inequities made worse by burning fossil fuels and pose additional safety risks.

As physicians, we must make our patients aware of all the reasons the “second-hand smoke” of hydrogen is as nefarious, or more so, than cigarette smoke to our patients, to our planet, and to us.


GBPSR’s Climate manager, Andee Krasner, and PSR National’s Environment and Health Program Director Barbara Gottlieb co-authored this important white paper on the health risks of fossil-fuel derived hydrogen.

This webinar from Food and Water Action Europe offers an excellent introduction to the public health risks inherent to developing this technology.

Brita Lundberg, Jane Limke and Eden Diamond. Vital Signs, November 2022: The false promise of fossil fuel derived hydrogen.

Both the Massachusetts Medical Society and AMA approved policy this year to increase public awareness of the negative health, safety and equity impacts of fossil fuel derived hydrogen and the dangers of mixing hydrogen and natural gas for use in homes.

For a more recent and comprehensive review, click here.