Land restoration can make a significant contribution to sustainable development at the global level

04-06-2021 | News item

A study by PBL Netherlands Environmental Assessment Agency shows that land restoration has global potential to contribute to multiple sustainability challenges, on food and agriculture, water, biodiversity and climate change. This study provides projections on the extent and risks of land degradation, and assesses the potential effects of land restoration compared to a future without restoration. Globally, an estimated five billion hectares of land can be restored through various restoration measures, resulting in improvements to soil carbon, water, agricultural production and climate change mitigation.

Implementing countries’ current land restoration commitments will require 10 years of investment, estimated at 0.04% to 0.21% of annual global GDP. Besides the advantages of land restoration, the disadvantage is that implementation is complex due to the involvement of many different parties. Stimulating land restoration measures therefore requires an integrated and coherent approach to governance and project development. Land restoration can limit but not stop biodiversity loss; this requires additional system changes. June 5th marks the launch of the UN Decade on Ecosystem Restoration (2021-2030).

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 in early 2022.

A future without 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 (Figure 1). 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 agriculture 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.

Area with negative productivity trend, corrected for climate change, 2000-2018. Bar chart showing that all regions show a negative productivity trend for total area and share of land areas, in particular sub-Saharan Africa, Middle East and North Africa, and Central and South America.
Figure 1Negative trends in productivity, based on satellite observations, is one of the three core indicators for land degradation.

New insights into a potential future with restoration

In the Restoration scenario, around five billion hectares are restored using potential land restoration measures. The measures include agroforestry, conservation agriculture, silvopasture, grazing management, grassland improvement, forest plantations, assisted natural regeneration and cross-slope barriers (Figure 2).

Locations of improved land management and restoration measures as applied in the restoration scenarios. World map that shows different combinations of restoration measures can be applied globally.
Figure 2The area where land restoration is estimated as potentially possible is based on the degree to which soil and vegetation can be restored given current land use. In most locations multiple measures are estimated to be possible, and they can often be combined as well.

Restoration results in multiple improvements in key ecosystem functions

Land condition and ecosystem functions improve between 2015 and 2050 due to the implementation of these restoration measures (Figure 3). 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.

Global effect of restoration scenarios in land condition and ecosystem functions. Bar chart left showing improvements across 6 ecosystem functions in two restoration scenarios compared to the baseline scenario in 2050. Bar chart right showing improvements in ecosystem functions in all three scenarios compared to 2050.
Figure 3The effect of the two land restoration scenarios, compared to the baseline scenario, shows the potential of land restoration to improve multiple ecosystem functions.

Current global restoration commitments cover around one billion hectares and therefore one fifth of the potential for restoration in the scenario projections

Of the potential area under the restoration scenarios that is suitable for restoration measures, around 20% is covered under countries’ current restoration commitments (Figure 4). Globally, these restoration commitments cover about 1 billion hectares, and potential area for restoration is estimated at 5.2 billion hectares, under the restoration scenarios. In sub-Saharan Africa, current restoration commitments add up to about half of the estimated area with potential for restoration. Sub-Saharan Africa is one of the regions with the largest share of land affected by land degradation, and it is also the region that is projected to have the highest expansion of agricultural land area up to 2050, underscoring the importance of the large commitments on land restoration in the region. The other regions show much lower coverage by current commitments relative to the potential restoration area.

Restoration commitments compared to areas restored in restoration scenarios. Bar chart showing that all global regions have commitments for restoration, that are around 20% of the total area that can be restored in restoration scenarios.
Figure 4The comparison between the commitments by countries and the estimated potential for land restoration shows that the ambitions by countries in Sub-Saharan Africa cover nearly half the estimated potential. In the other regions the gap between countries' commitments and the estimated potential for land restoration is larger.

Land restoration’s strength is also it’s weakness

The multiple potential benefits of restoration draw interest from actors in agriculture and sustainable land use, water, biodiversity conservation, and climate change adaptation and mitigation. This creates the risk of fragmentation in projects and policies. Integrating these actors into projects makes investment decisions complex and increases transaction costs. Fragmented planning, funding and implementation are underscored by the lack of coherence between national plans for land restoration in the Rio Conventions. 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. The benefits for livelihoods are also poorly understood. Knowledge on effective policy and governance approaches to bridge this complex distribution of costs and benefits remains scarce.

Moving from commitments to implementation at scale requires an integrated approach

The stimulation of land restoration measures requires an integrated governance approach and enabling environment, to build on the multiple synergies between different sustainable development ambitions, but also address complicated trade-offs. Even in the most ambitious scenario of land restoration and ambitious nature conservation, biodiversity still declines compared to 2015. Combining land restoration and protection measures with changes to production, supply chains and consumption patterns can achieve larger benefits.