Proceedings of the 11th International Carbon Dioxide Conference

Afforestation and reforestation (A/R) are seen as a main tool to provide carbon dioxide removal (CDR) at the scale needed to reach net-zero greenhouse gas emissions. However, we do not have a good understanding of where A/R is happening across the globe: The models used to quantify CO2 fluxes related to land use in global carbon budgets have not commonly separated out A/R from other land-use activities, and national greenhouse gas inventories (NGHGIs) do not separate CO2 fluxes on forests into those occurring due to human activity and those due to environmental changes. Here we present new estimates of CDR by A/R based on multiple bookkeeping models (those also used in GCP’s 2023 global carbon budget). We compare these with estimates of A/R and forest management based on the NGHGIs after correcting for natural fluxes. CDR through A/R amounts to 1,860 MtCO2 (1,160-2,230 MtCO2; full range across models) per year globally, averaged over 2013-2022. CDR in managed forests based on NGHGIs is 2000 MtCO2 per year over the same period. The two methods disagree on the trend over the last 20 years, with bookkeeping models showing a slight increase and adjusted NGHGIs a slight decrease in CDR, although both agree on a slowdown in the last few years. At the country level, the largest CDR through A/R stems from China, followed by the USA, Brazil, and Russia, but also small countries like Germany, France and Poland are among the top 10. Although A/R together with harvested wood products delivers more than 99% of all global CDR, current levels are not sufficient to compensate for residual emissions even under ambitious emission reduction scenarios, highlighting the need to expand forest area or scale up other CDR methods.