Fig. 6: Changes in fCO₂-product estimates over the last three updates of the global carbon budget analysis.

The last update of the fCO₂-product estimate was in 2023 (black line and grey shade). The previous two estimates were in 2022 (orange) and 2021 (blue). The left y axis represents the global CO₂ flux anomaly (for each time series the long-term mean between 1990 and 2020 was removed). GOBM estimates for the same three global carbon budget updates are also shown in dotted lines. The bar chart at the bottom represents the number of annual observations in the SOCAT database, for each annual version of SOCAT (v2021, v2022, and v2023; using the same colour code as for the line). fCO₂-product and GOBM data credit: Global Carbon Budget 2023, licensed under Creative Commons Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/deed.en), no changes were made.