The global tree restoration potential

TLDR

Tree restoration is one of the most effective climate‑change mitigation strategies, but future climate change may alter its potential coverage. Global mapping shows that up to 4.4 billion hectares of canopy could exist, with an additional 0.9 billion hectares available for restoration that could store 205 Gt of carbon, yet climate change could reduce this potential by ~223 million hectares by 2050, underscoring tree restoration as the most effective climate‑change solution and the urgent need for action.

Abstract

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.