New data from the National Oceanic and Atmospheric Administration show that hydrogen (H₂) concentrations increased from 2010 to 2019, which is consistent with the simulated increase in H₂ photochemical production (mainly from methane). But this cannot be reconciled with the expected decrease (increase) in H₂ anthropogenic emissions (soil deposition) in the same period. This shows gaps in our knowledge of the H₂ biogeochemical cycle that must be resolved to quantify the impact of higher H₂ usage.