Interest in rewilding is ripe but its future potential is uncertain
Restoring ecosystems is vital in addressing biodiversity loss, climate change and achieving the targets of the Kunming-Montreal Global Biodiversity Framework. Rewilding could play a key role in these restoration efforts, depending on demands for other types of land use in the future. The UK is one of the world’s most nature-depleted countries, with 71% of the land area being managed for agriculture.
Rewilding in the UK so far has often taken place on large private estates. However, new land management subsidies and an influx of private investment in nature-based solutions mean that rewilding may soon become more widespread. For example, in 2022 the UK Government announced plans to subsidise the restoration of 300,000 ha of wildlife habitats by 2042, with a special focus on wetland and peatland areas. Biodiversity and carbon credits entering the market has also created a major potential income stream for rewilding projects. These factors have led to some interest in rewilding among farmers and other land managers, often alongside regenerative agriculture.
While interest in rewilding is increasing, the potential of land available for rewilding in the future is uncertain. Many factors will affect this potential, including climate change impacts, changing priorities for land use and conservation and competing demands for land to produce goods.
Potential areas for rewilding can emerge in various ways:
· Land spared by intensification of land use elsewhere
· Popular demand for environmental restoration
· Desire for recreation
There are lots of opportunities for rewilding to occur, but it is important to consider priority conservation areas and societal objectives. Great Britain is a useful case study within the broader context of international rewilding efforts as it highlights the pressures that might prevent large scale rewilding and opportunities to support it.
A study to explore the potential of land for rewilding in Great Britain
A recent paper assesses and models the potential for rewilding in Great Britain in decades to come, taking into account different climatic and socioeconomic scenarios. Research involving land system simulations revealed that 0.5-2.7 million hectares may be available for rewilding in Great Britain by 2080.
Aside from long-term and loosely defined objectives for biodiversity recovery and carbon sequestration, rewilding areas do not usually have societal demands for specific goods or ecosystem services. This is the definition of rewilding used in the paper, which makes no assumptions about the exact nature of areas with potential for rewilding apart from the absence of extractive land management.
Researchers conducted a geographical assessment of the potential locations for rewilding in Great Britain. They used a high-resolution model (CRAFTY-GB) of the British land system linking local conditions to land management decisions and other key drivers. The objectives of the research were to define the extent of land areas available for rewilding, i.e. surplus to the requirements of other land uses such as food and timber production, in the absence of additional policy interventions.
The conditions considered included the future climatic and socio-economic environments defined by the Representative Concentration Pathways – Shared Socioeconomic Pathways (RCP-SSP) scenario framework. You can view a table detailing the scenarios and their implications for rewilding.
Potential areas for rewilding can be unmanaged, conservation-led and pastorally managed
Across all the scenarios, researchers identified areas with potential for rewilding (RPAs). There were two classes of land considered suitable for rewilding: unmanaged land that has been abandoned or never managed, and land managed for ecosystem services (e.g. flood regulation, landscape diversity and recreation) which they labelled as conservation.
A third type of land, subject to extensive pastoral management and supplying small quantities of livestock products alongside ecosystem services, was not included in the RPAs but was recorded as relevant, covering much of the UK’s most marginal agricultural land.
Results
Some key findings on RPA types were:
· The extent of land under very extensive grazing was large in all simulations, potentially providing further scope for rewilding.
· Relatively little land was modelled as becoming available to rewilding through abandonment.
· Conservation areas were more common and larger in extent than abandoned areas. Conservation areas usually emerged near to uplands. Abandoned land was more dispersed, but also occurred outside the most productive agricultural areas.
Differences between SSP outcomes were not always as expected
Spatial patterns were clearest in SSP1 (‘sustainability’) and least clear in SSP3 (‘regional rivalry’, where intense competition for land to satisfy food demands leads to increased agricultural use). SSP4 (‘inequality’) had the greatest levels of abandonment because intensification of the most productive agricultural areas meant that marginal production became uncompetitive.
Differences between SSP outcomes were sometimes surprising. For example, the large dietary shift away from livestock products in SSP1 (‘sustainability’) did not spare land proportionately for rewilding because this scenario also contained preferences for the remaining meat consumed to be produced via less intensive, pasture-based methods that require more land.
Across scenarios, many RPA hotspots were relatively close to urban centres, where demand for recreation could be satisfied.
Ancient woodland, peatland and wetland make up a small fraction of RPA areas
The locations of RPAs in 2080 that are characterised by ancient woodlands, peatlands and (potential) wetlands were fairly consistent across SSPs but made up a small proportion of the total RPA area.
There were some differences across SSPs, including:
· In SSP2 (‘middle of the road’), ancient woodland had usually become managed for very extensive grazing.
· Much ancient woodland was lost to other land uses, with the largest extent being maintained in SSP1 (‘sustainability’, where direct demand for native and natural woodland services exists) and SSP5 (‘fossil-fuelled development’, where woodland was indirectly spared by intensification elsewhere).
· The lowest extents were reached in SSP3 (‘regional rivalry’) because agricultural expansion occurred in response to shortfalls in food production.
· New native woodland peaked in SSP2. Some of these new native woodlands replaced non-native conifer plantations, especially in SSP1.
· The total wetland area was largest in SSP1, smaller in SSPs 2 and 4, and smallest in SSPs 3 and 5.
High potential in the least productive agricultural areas
The maintenance of food production alongside large RPAs is in line with previous studies’ findings that the least productive 20% of the UK’s farmland produces just 3% of calories and the least productive 10% just 1% of calories.
These least productive areas overlap substantially with high priority environments that host 90% of the most suitable locations for carbon storage and 91% of the best nature areas in the UK. These areas, and our RPAs, also occupy similar locations to the most habitat-rich areas of the UK. In contrast, existing protected areas in the UK do not cover the highest biodiversity priority areas.
From the limited but relatively untouched natural areas in SSP1 (‘sustainability’), to the small, fragmented and touristic areas in SSP5 (‘fossil fuelled development’), scope for natural processes to occur across large geographical extents varies hugely.
Climate change impacts are an uncertain threat
Carbon sequestration benefits are likely to be large but are uncertain, as climate change impacts could abruptly reverse any gains made. This is a major risk in high-emission scenarios, where carbon stocks and biodiversity are at serious risk. Targeted measures may be needed to preserve the largest carbon and biodiversity stocks in Britain’s land system, even if rewilding may emerge elsewhere in the absence of such measures.
There are lots of ecological and social implications to consider
Rewilding can have both positive and negative social implications. In the UK and internationally, priority areas for ecological restoration often overlap with the areas of relative socio-economic deprivation, suggesting a fundamental need – and, potentially, an opportunity – to generate benefits for people and nature in these locations.
Rewilding could occur at a large scale under a range of future conditions without impinging on essential land-based goods and services. However, the effects on other objectives and the extent to which policy and market-based interventions can shape those effects, requires and deserves further attention.