Offshore and urban methane emissions in Gabon

Atmospheric CH₄ mole fractions have strongly increased since 1750 due to human activity and continue to rise. Reducing CH₄ emissions is often easily feasible and also economically interesting, especially from fossil fuel sources (e. g. leakages). For the development of effective reduction strategies and to prioritize actions, CH₄ emissions, their spatial distribution and their variability must be well constrained. This study presents airborne top-down emission estimates from Gabonese offshore oil installations as well as emissions from the Libreville urban area. A correlation with installation age and oil production is discussed, and a comparison with reported data and other top-down studies is presented. Further, co-emitted species such as C₂H₆, CO₂, CO and NO_y are shown for both offshore fossil fuel sources and the mixture of different urban sources, which include contributions from fossil fuel and biogenic origins (e.g. landfills).