Molecular hydrogen is gaining global attention as an alternative to fossil fuels, with the potential to significantly reduce carbon dioxide emissions, other greenhouse gases, and air pollutants. Although hydrogen itself is not a greenhouse gas, its chemical oxidation can affect greenhouse gases like methane, ozone, and stratospheric water vapor. The uncertainties on the climate impact of hydrogen are large, because the overall budget of atmospheric hydrogen is less understood. Sources of hydrogen in the atmosphere include both direct emissions and oxidation by volatile organic compounds in the atmosphere. Hydrogen is removed by consumption of bacteria in soils and by oxidation of OH in the atmosphere.
This session invites contributions aimed at enhancing our understanding of the hydrogen budget and the potential impacts of increased hydrogen use. Areas of interest include: utilizing observations of hydrogen sources and sinks; quantifying the indirect climate effects of hydrogen emissions on methane, ozone, stratospheric water vapor, and aerosols; measuring and quantifying hydrogen leakages; and exploring scenarios of future hydrogen economies, including the associated co-benefits of reducing fossil fuel emissions for both the climate and environment.