As climate change continues to grip the world's attention, the shift toward cleaner energy alternatives gains traction, and hydrogen fuel is frequently proposed as a crucial element in this energy transition. Despite its potential, a recent study by MIT underscores a critical challenge for hydrogen's climate benefits: preventing leaks. According to a report published by MIT News, the climate impact of hydrogen leakage is "non-negligible" and could affect climate-warming greenhouse gases (GHGs) such as tropospheric ozone and methane, with the impact of methane being particularly significant.
The allure of hydrogen as a fuel is rooted in its clean-burning nature, releasing no GHGs when combusted. However, the research team at MIT, with funding from the university's Energy Initiative’s Future Energy Systems Center, has developed a model that paints a more nuanced picture, disclosing that leaked hydrogen can indirectly cause climate change. As hydrogen leaks from pipelines or storage facilities, it can deplete the hydroxyl radical (OH)—often referred to as the "detergent of the atmosphere" for its role in removing methane and other pollutants from the air.
Delving into the specifics of this impact, the study—led by Candice Chen, a PhD candidate in the Department of Earth, Atmospheric and Planetary Sciences (EAPS) at MIT—utilizes a comprehensive approach involving 66 chemical reactions, contrasting with the lesser "four-equation model" used in previous research. While both methodologies recognize the deleterious effects of hydrogen leakage, the new model suggests the climate impacts might not be as critical as once thought. Chen explains, "There’s a small countering effect. Indirectly, the methane helps produce the thing that’s getting rid of it." This counterbalance, resulting from the conversion of increased methane into new OH radicals, was not fully captured by the less robust four-equation model used in 2022.
When comparing leaked hydrogen to leaked natural gas, the MIT teams reveal an important advantage of hydrogen despite the prevention challenges – its climate impact is about three times less than that of methane, on a per mass basis. This finding, while stressing the importance of controlling leaks, tentatively endorses the switch from natural gas to hydrogen. However, focusing on the bigger picture, the study indicates that establishing leak-free hydrogen infrastructure is imperative to realize hydrogen's potential as an effective alternative to fossil fuels.
In response to the findings of the study, the researchers offer a clear directive for the process of transition to hydrogen fuel. It's not merely about adopting hydrogen, but ensuring its emission containment is at the forefront of the move. As MIT's report summarizes, the team's research opens avenues for protecting the climate more effectively - by minimizing leakage of hydrogen, we stand a chance at achieving net-zero carbon emissions by the year 2050, as targeted by global initiatives.
