The global potential for land restoration: Scenarios for the Global Land Outlook 2
Land restoration has the potential to deliver multiple environmental and societal benefits simultaneously, making it a highly integrated solution for sustainable development.
This study quantifies the potential effects of land restoration for soil, food, water, biodiversity and climate change at the global and regional levels, using three global land-use scenarios up to 2050.
- The way that land is used, managed and protected is central to achieving the goals of the UN Conventions on land degradation and desertification, climate change and biodiversity, as well as many of the Sustainable Development Goals. This is because the choices, synergies and trade-offs between sustainability ambitions often materialize on land.
Over the past years, attention to and ambitions for restoration have gained momentum, culminating in the UN Decade on Ecosystem Restoration (2021–2030). This study quantifies the potential effects of land restoration at the global and regional levels.
Three global land-use scenarios up to 2050 were constructed and analyzed to provide a view of the extent and risks of land degradation, and to estimate the potential of land restoration compared to a future without restoration. These three scenarios are the Baseline, Restoration and Restoration & Protection scenarios. The effects of land restoration were assessed for natural area, biodiversity, soil organic carbon, agricultural yields, water regulation and carbon storage
Three scenarios to explore the potential of land restoration
The Baseline scenario shows what would happen between 2015 and 2050 without land restoration measures.
- Land management negatively affects soil and biomass productivity on an estimated 12% of the global land area.
- Agricultural productivity is projected to increase, but current land management practices have an average negative effect of 2%, rising to 6% to 10% in some regions.
- Cropland expands by about 20% (~300 million ha), at the expense of natural areas.
- Of the remaining biodiversity, 6% is lost due to land-use change, intensive production and climate change.
- Average annual carbon emissions between 2015 and 2050 from land-use change and land management amount to 16% of current annual emissions.
In the Restoration scenario, around five billion hectares are restored using potential land restoration measures.
- Land condition and ecosystem functions improve between 2015 and 2050 due to the implementation of these measures.
- The measures include agroforestry, conservation agriculture, silvopasture, grazing management, grassland improvement, forest plantations, assisted natural regeneration and cross-slope barriers.
- Restoration boosts agricultural yields globally by 2% and by up to 10% in some regions, compared to the Baseline scenario.
- Conversion of natural land to agriculture is reduced and biodiversity loss is 11% less in 2050 compared to the Baseline scenario.
- Carbon storage in soils increases and loss of carbon in vegetation is reduced, resulting in a net gain of 17 GtC between 2015 and 2050.
- This can make a substantial contribution to meeting climate ambitions, when compared to current global emissions of 11 GtC/yr.
In the Restoration & Protection scenario, restoration measures are combined with protection of areas that are important to maintain ecosystem functions.
- This translates into 400 million hectares more natural land, and the prevention of one third of the global biodiversity loss in the Baseline scenario.
- However, food prices increase relative to the Restoration scenario and agriculture is required to intensify faster due to limited available land.
- Compared to the Baseline scenario, an additional 83 Gt of carbon is stored in soils and vegetation, equivalent to more than 7 years of current global emission.
Current global restoration commitments cover around one billion hectares and therefore one fifth of the potential for restoration in the scenario projections. Almost half of all commitments are found in sub-Saharan Africa. There are also large commitments in South Asia and Central and South America, relative to the total land area. Other regions report much smaller commitments to land restoration.
Implementing the current commitments requires investments estimated at 0.04% to 0.21% of annual global GDP for 10 years (USD 300 billion to USD 1,670 billion). Estimated costs are highest for sub-Saharan Africa due to the large restoration commitments in this region. The costs of implementing the restoration commitments are likely to be prohibitive for developing countries, unless international cost-sharing mechanisms for restoration are developed.
Restoration measures can prevent future land degradation, and this should be accounted for when assessing investment in restoration measures.
- Not accounting for prevented impacts would underestimate the potential benefits of land restoration.
- Prevention is crucial because land restoration is generally a long-term process.
- The stimulation of land restoration measures requires countries to integrate restoration into existing policies and institutions.
- Given the large commitments that countries are making, in particular in improved land management, effective governance requires policy interventions across multiple levels and sectors.
- While there are many different policies and institutions to build on or to newly develop, there is no one-size-fits-all policy.
- Policymakers require evidence of what works under which conditions, and such information is imperative for making the UN Decade of Restoration a success.
- Combining land restoration and protection measures with changes to production, supply chains and consumption patterns can achieve larger benefits.
- These measures can have synergy with land restoration, as reducing pressure on land can further improve the potential for land restoration
Global costs of land restoration and benefits to households. The benefits of land restoration are significant, but implementation of measures is complex due to high costs and their distribution.
The potential benefits of restoration as shown by the Restoration scenario are significant, although some potentially negative effects could not yet be incorporated in the modelling. However, implementing current commitments, or going beyond that, requires addressing how such implementation should be financed, how to balance private and public costs and benefits, and how to enable effective governance mechanisms.
Implementing current land restoration commitments requires investments that are estimated at 0.04% to 0.21% of annual global GDP, if implementation would be spread out over 10 years. The total costs range from USD 300 billion to USD 1,670 billion. The large spread is mainly due to large differences in the cost data available from various data sources.
Balancing the public and private benefits of land restoration requires effective governance. Effective governance of land restoration efforts requires policy interventions at micro, meso and macro levels. While land restoration often starts with micro-level restoration projects, there is scope for enhancing the incentives by landowners by considering complementary national policies. Such policies may further leverage private investment by providing better safeguards and legal certainty for private investors
There are no silver bullets for choosing the right mix of policies or projects to incentivize land restoration at scale. There is a paucity of empirical evidence on combinations of policies and projects that have proved successful for land restoration. Such information is urgently needed as the required interventions are site- or country-specific, and also as benefits take decades to materialize.
- This finding implies a need for more policy experimentation and evaluation to better understand how land restoration can be achieved at scale, at the lowest possible cost to societies. Such information is imperative for making the UN Decade of Restoration a success.
This PBL study on global restoration scenarios was carried out at the request of the United Nations Convention to Combat Desertification (UNCCD), which was established to combat land degradation, desertification and drought. The Convention addresses the improvement of living conditions of people in drylands and the restoration of degraded land and soils. This PBL study is a central component of the Global Land Outlook, 2nd edition that will be published late 2021.
The unformatted edited final full report can be requested from the authors. The full formatted report will be available shortly online.
- Download the report (PDF, 1 MB)
- To report Goals and commitments for the restoration decade
- To report Exploring future changes in land use and land condition (Global Land Outlook 2017)
- To PBL Theme site Nature based solutions
- To UNDP report Future perspectives on land for eastern Africa