Laura Yang: Potential overestimation of hydrogen's GWP-100

Abstract

Hydrogen fuel can help decarbonize the economy, but hydrogen leakage has indirect climate consequences. Atmospheric oxidation of hydrogen by hydroxyl radicals (OH) increases methane, ozone, and stratospheric water vapor concentrations. Current global 3‐D atmospheric chemistry models estimate a global warming potential for hydrogen of 12 ± 3 over a 100‐year horizon (GWP‐100), but these models overestimate global OH concentrations and underestimate OH reactivity (OHR). These OH biases lead to overestimates of the responses of methane and ozone to hydrogen. In this talk, I will present how models OH bias may lead to an overestimation of hydrogen’s GWP-100 by 20%. I will also discuss how a better understanding of the factors controlling global OH concentrations and OHR is needed to refine hydrogen GWP estimates.

Bio

Laura Yang, Ph.D., is an atmospheric chemist and Postdoctoral Research Fellow at Washington University in St. Louis. She earned her Ph.D. in Environmental Science and Engineering from Harvard University as an NSF Graduate Research Fellow in 2024. Her research combines chemical transport models, satellite observations, and aircraft data to better understand air quality, atmospheric oxidation chemistry, and the climate impacts of emerging energy systems. At META, she will discuss how assessment of hydrogen’s climate impact is affected by biases in modeled hydroxyl radical (OH) concentrations, and what this means for evaluating hydrogen as part of the clean energy transition.