Carbon Emissions and Removals by Forests: New Estimates 1990–2020

Abstract. Trends in global, regional and national CO₂ emissions and removals from forest for the period 1990–2020, are estimated for the first time using data from the Forest Resources Assessment (FRA) 2020, providing new information with respect to the previous FRA 2015. Estimates indicate significant reduction of deforestation emissions over the study period, albeit more slowly than previously assessed, from an average of 4.3 Gt CO₂ yr⁻¹ during 1991–2000, to an average of 2.9 Gt CO₂ yr⁻¹ during 2016–2020. Remaining forest land was a significant net carbon sink globally and over the entire period, albeit decreasing in strength, from −3.4 Gt CO₂ yr⁻¹ in 1991–2000 to −2.5 Gt CO₂ yr⁻¹ during 2016–2020. The overall net contribution of forests to atmospheric CO₂(i.e., the combined effect of deforestation and forest emissions/removals) was an overall emission source of roughly 0.4 Gt CO₂ yr⁻¹ on average during 1991–2020, more than one-third less than previously estimated. Remarkably, the new data also suggest an overall net sink of about −0.7 Gt CO₂ yr⁻¹ during 2011–2015, never reported before. Forest emissions/removals data independently reported by countries to the United Nations Framework on Climate Change were in excellent agreement with the FAO estimates over the entire period 1990–2020, confirming a large sink on forest land estimated for 2011–2015. Data are made available as open access via the Zenodo portal (Tubiello, 2020), with DOI 10.5281/zenodo.3941973.