What is our assessment?

Based on our assessment, removing methane from the air using photocatalytic methane-oxidizing surface coatings is plausible, but its effectiveness and potential climate impact are currently limited by technological and practical uncertainties. However, because methane is such potent GHG, we will “Keep Watching” this solution. 

What is it?

This solution aims to remove methane from the air by coating large surfaces that contact air, such as buildings and wind turbine blades, with photocatalytic chemicals that convert methane to CO₂ on contact (Jackson et al., 2021; Lebling & Harasaki, 2025). Methane-oxidizing coatings use sunlight to drive the chemical reaction and rely on natural air movement to bring methane in the air into contact with the coated surface (Abernethy & Jackson, 2024). 

Does it work?

Methane is a potent but short-lived greenhouse gas, more than 80 times stronger than CO₂ at trapping heat on a 20-year basis (IPCC, 2023). Actions that accelerate methane conversion to CO₂ would reduce its disproportionate warming impact (Jackson et al., 2019). Several photocatalytic compounds, such as titanium dioxide, can convert methane into CO₂ and can be incorporated into thin coatings such as paint and applied to a variety of surfaces. However, the chemical reaction to convert methane to CO₂ is not 100% efficient and, because the atmospheric concentration of methane is so low (~2 ppm compared to 430 ppm for CO₂ ), the amount of methane removed is limited by the area of the coated surface and the rate at which methane molecules contact it (Abernethy & Jackson, 2024; Pennacchio et al., 2024). Research into using methane-oxidizing coatings is still in its early stages and limited to a few modeling and laboratory studies. Modeling estimates suggest that the area of coated surfaces needed to achieve a meaningful climate impact would be impractically large (Pennacchio et al., 2024). 

Why are we excited?

Because methane is such a potent GHG, actions that reduce its concentration in the atmosphere have immediate climate benefits. Unlike direct air capture or carbon capture and storage, there is no need to capture or store any gases because the goal is to oxidize methane to CO₂ (Ming et al., 2022). Using a chemical treatment that can be incorporated into coating materials such as paint is minimally invasive or disruptive. In addition, because the solution relies on natural air movement rather than fans, its energy demands and operating costs are low. The effectiveness of this solution could be enhanced if it were deployed in areas with habitually elevated methane concentrations, such as cattle, waste management facilities, oil and gas facilities, and rice paddies (Nisbet-Jones et al., 2021). 

Why are we concerned?

Significant advances in the methane removal efficiency of photocatalytic surface coatings are needed for this solution to be effective, scalable, and practical (Lebling & Harasaki, 2025). Other unknowns include the durability and lifespan of the photocatalytic coatings on different types of surfaces and under different environmental and weather conditions (Lei et al., 2025; Liu et al., 2023). Costs are unknown due to these limitations, and could be high relative to other more targeted methane reduction solutions such as managing oil and gas methane, managing coal mine methane, improving landfill management, and increasing centralized composting. New tools for monitoring and measuring changes in the low concentrations of atmospheric methane will need to be developed to quantify the amounts of methane removed for accurate accounting and verification. Finally, some researchers argue that use of photocatalytic coatings to neutralize potent GHGs would be more effectively and impactfully directed at longer-lived climate pollutants such as nitrous oxide (Lackner, 2020).