Given the critical role of hydrogen (H₂) in the global energy transition to mitigate climate change, understanding its biogeochemical cycle becomes crucial. H2 emissions from leakages, venting, and incomplete combustion can alter atmospheric chemistry and affect Earth’s radiative balance. Despite recent advances, our knowledge of the H₂ biogeochemical cycle remains limited. This session will feature cutting-edge research on the global H₂ cycle, spanning experimental and theoretical approaches of H₂ biogeochemistry, as well as top-down and bottom-up assessments of H₂ sources and sinks. We invite contributions that examine the H₂ budget across various spatial and temporal scales and also encourage studies that assess the social, environmental, and climatic implications of increased H₂ usage.