WCRP Joint Scientific Committee member, Pierre Friedlingstein, and colleagues have published the Global Carbon Budget 2020 (https://doi.org/10.5194/essd-12-3269-2020).
Produced by more than 80 researchers working from universities and research institutions in 15 countries, this annual product compiles and assesses reports, papers, measurements, and model outputs to quantify sources and sinks of carbon in units of gigatonnes of carbon per year (GtC yr-1). Data up to the end of 2019 show a small (0.1 %) increase in carbon emissions for 2019 (11.5 GtC yr-1) as part of persistent fossil fuel, cement production, and land use change emissions. Sinks – ocean and land combined – amounted to 5.7 GtC yr-1 for 2019, resulting in an atmospheric CO2 increase of 5.4 GtC yr-1 (2.5 parts per million per year) and leading to 2019 yearly averaged global atmospheric CO2 concentrations of essentially 410 parts per million. A small imbalance (0.3 GtC yr-1) for 2019 demonstrates continuing reduction of key uncertainties but an as-yet imperfect quantification of the longer-term (1959–2019) variability of land sources and sinks and of ocean sinks. Preliminary estimates for 2020 relative to 2019 suggest a decrease in fossil fuel emissions of approximately –7 %; a full account of 2020 sources and sinks will appear in next year's global carbon budget. As part of the larger Global Carbon Project, these authors and institutions make data, analysis, and quantification – including explicit uncertainties and country-by-country accounts – completely freely and openly available through ESSD and the Integrated Carbon Observation System.