WMO Greenhouse Gas Bulletin - No.17: The State of Greenhouse Gases in the Atmosphere Based on Global Observations through 2020

This Bulletin represents the analysis of observations from the WMO GAW Programme through 2020. It shows globally averaged surface mole fractions for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and compares them with the mole fractions during the previous year and with the preindustrial levels. It also provides insights on the change in radiative forcing by long-lived GHGs (LLGHGs) and contribution of individual gases to this increase.