This study models the total amount of land globally that is suitable for reforestation, finding that there is sufficient space to meet the IPCC’s recommendation of reforestation on 1 billion hectares to limit global warming to 1.5C by 2050. The potential forest land identified in this study excludes urban and agricultural land; rather, it “exists in areas that were previously degraded, dominated by sparse vegetation, grasslands, and degraded bare soils” [Bastin 2019]. Yet for reforestation efforts to meet this potential, time is of the essence. By 2050, climate change will have shrunk the additional amount of land capable of supporting forest ecosystems by about a quarter.
The restoration of trees remains among the most effective strategies for climate change mitigation. We mapped the global potential tree coverage to show that 4.4 billion hectares of canopy cover could exist under the current climate. Excluding existing trees and agricultural and urban areas, we found that there is room for an extra 0.9 billion hectares of canopy cover, which could store 205 gigatonnes of carbon in areas that would naturally support woodlands and forests.This highlights global tree restoration as our most effective climate change solution to date. However, climate change will alter this potential tree coverage.We estimate that if we cannot deviate from the current trajectory, the global potential canopy cover may shrink by ~223 million hectares by 2050, with the vast majority of losses occurring in the tropics. Our results highlight the opportunity of climate change mitigation through global tree restoration but also the urgent need for action [Bastin 2019: 1].
The restoration of trees remains among the most effective strategies for climate change mitigation [Bastin 2019: 1].
More than 50% of the tree restoration potential can be found in only six countries (in million hectares: Russia,+151; United States,+103; Canada, +78.4; Australia, +58; Brazil, +49.7; and China, +40.2), stressing the important responsibility of some of the world’s leading economies.
Bastin, Jean-Francois, et al., 2019, The global tree restoration potential, Science 365, https://www.crowtherlab.com/wp-content/uploads/2019/06/190705_The-global-tree-restoration-potential.pdf.