Founded in 2005 as an Ohio-based environmental newspaper, EcoWatch is a digital platform dedicated to publishing quality, science-based content on environmental issues, causes, and solutions.
A type of geoengineering technology designed to oxidize atmospheric methane is not effective enough to reduce the impact of emissions, a new study has revealed.
Atmospheric scientists at the University of Utah were not convinced of a recent proposal to put hydrogen peroxide into the atmosphere as a way to oxidize methane emissions and improve air quality.
To test whether this method could work, the scientists used GEOS-Chem, a global chemical-transport 3D model, to model the use of aerosolized hydrogen peroxide, which would be sprayed from 50 600-meter-tall towers around North America.
Researchers modeled what would happen if each tower sprayed 612 grams of the hydrogen peroxide per second for 10 hours daily over the course of one year, a scenario based on a real proposal by an unnamed company.
However, the models showed that this scenario did not make much of a dent in the methane levels, and the technology could even lead to higher amounts of particulate matter pollution in areas that already had poor winter air quality. The scientists published their findings in the journal Environmental Science & Technology.
"This proposed solution just won't remove any meaningful amount of methane from the atmosphere. It's not going to solve global warming. At most, we found 50 towers could reduce 0.01% of annual anthropogenic methane emissions," Jessica Haskins, co-author of the study and an assistant professor of atmospheric sciences at University of Utah, said in a statement. "You'd need about 352,000 of them to remove 50% of anthropogenic methane. It's an insane number. And if you did 50 high-emission towers, you'd still need about 43,000."
As Haskins explained, the hydrogen peroxide would break down in the presence of sunlight and produce hydroxyl radicals (OH), which speed up the conversion of methane into carbon dioxide. While carbon dioxide emissions are also a concern for climate change, methane has a greater warming potential of up to 84 times compared to carbon dioxide, according to the European Commission.
But in the environment, the researchers explained that the hydroxyl radicals tend to react more to common double-bonded compounds found in the atmosphere, rather than the single-bonded methane molecules.
"OH doesn't react fast with methane," Haskins explained. "It's reacting with so many other things."
According to the study, multiple companies and organizations are exploring geoengineering to oxidize methane and other greenhouse gas emissions, primarily through iron-salt aerosols and hydrogen peroxide.
However, more research is being done to reveal how these potential technologies could actually impact the atmosphere and climate change.
A separate study, pre-printed in December 2024, also used modeling to explore how using tropospheric hydroxyl radicals (OH) or chlorine (Cl) in the atmosphere could decrease greenhouse gas emissions, including methane. The author concluded that using hydrogen peroxide was likely not feasible based on the amount needed to actually decrease atmospheric methane levels. Further, the research showed that all geoengineering methods analyzed in the study led to an increase in particulate matter pollution, which even exceeded air quality standards in some locations.
"We could buy ourselves about 50 years and avoid some of the immediate impacts of climate change if we did this, but no one had actually previously done any side-effects studies to see what was going to happen," Haskins said. "This is very first paper to assess any air quality side effects of such geoengineering solutions."
The study authors are not completely discrediting these technologies, but they do warn that more research and consideration is necessary before actually executing these methods.
"There's potential that future research could show that the air quality impacts of placing these towers close to methane point sources is minimal if they're activated at certain times of the year, and far from large population centers," said Alfred Mayhew, co-author of the study and a postdoctoral researcher with the Wilkes Center for Climate Science & Policy at University of Utah. "If that's the case, then this technology (or similar approaches) could play a very small role in combatting warming, but it's clear from our work that the air-quality side effects should be placed as a central consideration for any proposed real-world implementation of technology like this."