All modelled pathways limiting global temperature rise to 1.5°C with no or limited overshoot rely on carbon removal. Reforestation is a relatively cost-effective, readily available approach to carbon removal that, when implemented appropriately (i.e., by focusing on recovering forests’ ecological functions, rather than solely on replanting trees), can also generate additional benefits for adaptation, sustainable development, and biodiversity conservation. Restoring terrestrial ecosystems, including forests, is also a standalone goal of the GLD.
Yet data limitations pose significant challenges to monitoring reforestation globally, and remotely sensed data on the gross area of tree cover gain offers the best available proxy. However, these data may include tree cover gains that, while potentially beneficial for climate mitigation, do not meet common definitions of reforestation, such as afforestation across historically non-forested lands or regrowth after harvesting within already established plantations. In addition, increases in tree cover occur gradually as these plants grow, making it more challenging to reliably estimate using satellite remote sensing methods over short timescales.
Still, historical cumulative data suggest that worldwide, a total of 130 million hectares (Mha) experienced tree cover gain from 2000 to 2020. Yet this average annual rate of tree cover gain (6.5 Mha per year) will likely need to accelerate to help limit warming to 1.5°C; reverse forest loss as pledged in the GLD; and deliver the Bonn Challenge pledge to bring 350 Mha of deforested and degraded land into restoration by 2030.
Critically, while reforestation is needed to meet climate and biodiversity goals, it cannot serve as a substitute for protecting standing forests. For example, it may take decades (if not longer) for these ecosystems to regain species diversity, ecosystem structure, and ecological functions, all of which may impact carbon cycling and GHG fluxes within these ecosystems.
—
Note: We used tree cover gain (total gross area gained from 2000 to 2020) as the best available proxy indicator for reforestation. Potapov et al. (2022) define tree cover gain as the establishment or recovery of tree cover (woody vegetation with a height of greater than or equal to five meters) by the year 2020 in areas that did not have tree cover in the year 2000. Historical data were estimated using maps derived from remotely sensed data, and accordingly, they contain a degree of uncertainty.
Learn more about the methods for estimating reforestation (including the known limitations) in the most recent State of Climate Action report.
Full description, licensing, and other information available at original data source (Potapov et al. 2022)
All modelled pathways limiting global temperature rise to 1.5°C with no or limited overshoot rely on carbon removal. Reforestation is a relatively cost-effective, readily available approach to carbon removal that, when implemented appropriately (i.e., by focusing on recovering forests’ ecological functions, rather than solely on replanting trees), can also generate additional benefits for adaptation, sustainable development, and biodiversity conservation. Restoring terrestrial ecosystems, including forests, is also a standalone goal of the GLD.
Yet data limitations pose significant challenges to monitoring reforestation globally, and remotely sensed data on the gross area of tree cover gain offers the best available proxy. However, these data may include tree cover gains that, while potentially beneficial for climate mitigation, do not meet common definitions of reforestation, such as afforestation across historically non-forested lands or regrowth after harvesting within already established plantations. In addition, increases in tree cover occur gradually as these plants grow, making it more challenging to reliably estimate using satellite remote sensing methods over short timescales.
Still, historical cumulative data suggest that worldwide, a total of 130 million hectares (Mha) experienced tree cover gain from 2000 to 2020. Yet this average annual rate of tree cover gain (6.5 Mha per year) will likely need to accelerate to help limit warming to 1.5°C; reverse forest loss as pledged in the GLD; and deliver the Bonn Challenge pledge to bring 350 Mha of deforested and degraded land into restoration by 2030.
Critically, while reforestation is needed to meet climate and biodiversity goals, it cannot serve as a substitute for protecting standing forests. For example, it may take decades (if not longer) for these ecosystems to regain species diversity, ecosystem structure, and ecological functions, all of which may impact carbon cycling and GHG fluxes within these ecosystems.
—
Note: We used tree cover gain (total gross area gained from 2000 to 2020) as the best available proxy indicator for reforestation. Potapov et al. (2022) define tree cover gain as the establishment or recovery of tree cover (woody vegetation with a height of greater than or equal to five meters) by the year 2020 in areas that did not have tree cover in the year 2000. Historical data were estimated using maps derived from remotely sensed data, and accordingly, they contain a degree of uncertainty.
Learn more about the methods for estimating reforestation (including the known limitations) in the most recent State of Climate Action report.
Full description, licensing, and other information available at original data source (Potapov et al. 2022)
