India has been a tree plantation laboratory for over 200 years and has experimented with tree plantations, offering important lessons about the consequences different approaches to restoring forests have on local communities and the wider environment. Tree restoration has been promoted to reduce the amount of carbon in the atmosphere that warms the globe while simultaneously increasing biodiversity, the advantages that ecosystems provide, and even the productivity of livelihoods.
Global forested land restoration may be able to absorb carbon dioxide from the atmosphere and slow down global warming. The authors of the DOB Ecology-funded study created a global model of the potential for forest restoration using actual measurements of the amount of forest cover. The amount of extra tree cover that might exist outside of current woods, agricultural, and urban areas is depicted on their spatially explicit maps.
An additional 0.9 billion hectares of continuous forest might be supported by ecosystems. At maturity, this would imply growth in a wooded area of more than 25% and more than 200 gigatonnes of additional carbon. A modification of this kind could hold a quarter of the present atmospheric carbon stock.
The potential for global forest cover
One of our best chances to slow down the global increase in CO2 concentrations is probably the photosynthetic carbon capture that trees do. As a result, several international projects [including the New York Declaration on Forests, the associated AFR100, and the Bonn Challenge] have set high goals to support the conservation, afforestation, and restoration of forests worldwide. According to the Intergovernmental Panel on Climate Change’s (IPCC) most recent special report, 1 billion more hectares of forest would be needed by 2050 to keep global warming to 1.5°C.
Previous efforts to estimate global tree cover
To obtain rough estimates of the worldwide deterioration of forests, previous attempts to assess the potential for global tree cover have scaled current vegetation estimates to the biome or ecoregion levels. But to assess which environments could support trees numerically, we need to create models based on direct measurements of tree cover (as opposed to models produced from satellite data) from protected regions, where human activity hasn’t had a significant impact on the plant cover. We can interpolate these estimates of “natural tree cover” across the globe to produce a predictive understanding of the potential tree cover in the absence of human activity, provided we have enough observations spanning the entire range of environmental conditions, from the lowest to the highest possible tree cover.
Global Photointerpretation dataset offers the capacity to characterize potential tree cover under different environmental conditions
The ability to characterize the prospective tree cover under a particular set of environmental conditions is provided by the global photo interpretation dataset. The resulting publicly available map, which respects the natural ecosystem type (for example, from wooded savannah to dense forest), can be used as a benchmark map to evaluate restoration opportunities (such as planting trees and natural assisted regeneration) worldwide. Restoration efforts, however, must not result in the disappearance of current natural ecosystems, such as native grasslands, which can support enormous amounts of carbon and biodiversity. Our maps, which make use of current global land-cover layers, show that at least 0.9 billion ha more of canopy cover is probably possible.
Restored woodlands and forests have the potential to store up to 205 GtC if they are allowed to grow to a level comparable to that of current protected area ecosystems. Achieving this maximal restoration capability would lessen a significant amount of the global human atmospheric carbon burden to date (~300 GtC) since the airborne fraction of carbon dioxide is approximately 45% (1). Accordingly, one of the best options must slowing down climate change is ecosystem restoration.