Limited carbon sequestration potential from global ecosystem restoration

Abstract

Ecosystem restoration is increasingly recognized as a means of climate change mitigation. Recent global-scale studies have suggested that ecosystem restoration could offset a substantial fraction of human carbon emissions since the Industrial Revolution. However, global carbon sequestration potential remains uncertain due to the tree-centric view of some models and difficulties in modelling restoration across different ecosystem types. Here we applied a model-based prediction workflow to estimate the carbon capture potential of restoring forest, shrubland, grassland and wetland ecosystems until 2100. We found that the maximum sequestration potential is 96.9 Gt of carbon, equivalent to 17.6% of the anthropogenic emissions to date, or 3.7–12.0% if taking into account future emissions until 2100. Our results suggest that ecosystem restoration has limited potential for climate change mitigation even if orchestrated with a pervasive shift towards sustainable, low-emissions economies globally. In addition, if we plan restoration targets to match future climatic conditions and consider state transitions of currently natural ecosystems due to climate change, the potential for natural climate solutions related to ecosystem restoration is close to zero. Therefore, we recommend that ecosystem restoration is pursued primarily for restoring biodiversity, supporting livelihoods and resilience of ecosystem services, as the climate mitigation potential will vary depending on the state transitions that occur between vegetation types. The maximum carbon sequestration potential from global terrestrial ecosystem restoration efforts until 2100 is 96.9 Gt, which is equivalent to 3.7–12.0% of anthropogenic emissions until then, according to model projections.