Global Carbon Budget 2022

Background

“Global Carbon Budget 2022” extends the series of budgets to 2021 with a projection for 2022, documenting that fossil carbon dioxide (CO2) emissions likely surpass pre-COVID pandemic levels. Atmospheric CO2 growth remains high, with decadal mean growth around 5.2 GtC yr⁻¹ for 2012-2021 and concentrations exceeding 414 ppm.

Goals and Methods

This study updates fossil and land-use emissions, atmospheric growth, and land and ocean sinks for 1959-2021 and refines evaluation metrics for sink models. Fossil emissions are derived from country-level energy and cement data, harmonized across the Carbon Dioxide Information Analysis Center (CDIAC), BP, and cement process data; land-use change emissions come from multiple bookkeeping models driven by Land-Use Harmonization (LUH2) and History Database of the Global Environment 3.3 (HYDE3.3). Land and ocean sinks are estimated from process models constrained by expanded observation sets, with the budget imbalance used as a consistency check.

Conclusions and Takeaways

For 2012-2021, fossil emissions averaged 9.6 ± 0.5 GtC yr⁻¹ and land-use change emissions 1.2 ± 0.7 GtC yr⁻¹, with atmospheric growth of 5.2 ± 0.02 GtC yr⁻¹, an ocean sink of 2.9 ± 0.4 GtC yr⁻¹, and a land sink of 3.1 ± 0.6 GtC yr⁻¹, yielding a small negative budget imbalance. In 2021, fossil emissions reached 9.9 ± 0.5 GtC yr⁻¹, with projections placing 2022 around 10.0 ± 0.5 GtC yr⁻¹ and total emissions (including land-use change) near 11.1 ± 0.9 GtC yr⁻¹, indicating that the temporary dip in emissions during the COVID-19 pandemic is over. The budget confirms that the land and ocean combined still absorb about half of anthropogenic CO2, but highlights no clear long-term trend in the ocean-borne fraction and continuing uncertainties in land-use emissions, all of which constrain precise assessments of remaining carbon space for 1.5-2 °C targets.