Model underestimates of OH reactivity cause overestimate of hydrogen's climate impact

Deploying hydrogen technologies is one option to reduce energy carbon dioxide emissions, but recent studies have called attention to the indirect climate implications of fugitive hydrogen emissions. We find that biases in hydroxyl (OH) radical concentrations and reactivity in current atmospheric chemistry models may cause a 20% overestimate of the hydrogen Global Warming Potential (GWP). A better understanding of OH chemistry is critical for reliable estimates of the hydrogen GWP.