Rewilding is an approach to nature restoration that animates conservationists, farmers and even the Royal family like perhaps no other. Notwithstanding the controversies, what would it take for rewilding to play a bigger role in climate change action in the UK, asks Leo Mercer.

For some, rewilding is emblematic of a bygone era where wolves were free to stalk a wild hinterland with no human presence. For others, rewilding conjures up images of healthy, resilient and dynamic landscapes that regenerate habitats, priority ecosystems and the species that live within them. Different viewpoints aside, rewilding is increasing in prominence as conservationists, landowners and urban dwellers push to restore nature and also reimagine how land is used in order to better adapt to and mitigate climate change. 

The stakes are high. Last month, the latest report from the United Nations Environment Programme forecast that the world is heading for a 2.5–2.9°C temperature rise above pre-industrial levels by 2100. There is widespread understanding that removal of emissions needs to be pursued in parallel to emission reductions to keep the Paris Agreement target of 1.5°C alive. Nature is also under severe pressure. Since 1970, the UK has seen precipitous falls in aggregate species abundance with 13 per cent declines on average and a 60 per cent reduction in the abundance of priority species. A goal for many governments is to understand how to respond to climate change while also delivering co-benefits for nature.

Historically, a healthy and resilient natural environment has not been ascribed monetary value. The Dasgupta Review for the UK government on the economics of biodiversity highlights the interlinkages between economic systems and nature. By failing to value nature and account for it in decision-making processes, we have facilitated its continued degradation. Thus, by quantifying with much greater precision the sequestration and other non-carbon benefits of rewilded land, we can begin to ever so slightly tilt the balance in favour of these land uses, which have historically been un- or undervalued.

We have recently considered these issues by exploring how rewilding can decarbonise land use in the UK. Our report was devised to help government agencies across all the UK’s nations understand how to better include “nature” in net zero pathways, by showing how rewilding fits into current agri-environmental policy and what data would be needed should administrations decide to target rewilding for net zero purposes.

Rewilding and net zero – definitional issues and data gaps hampering progress

In the UK there are substantial pressures on land from housing, farming, green energy and infrastructure development, as well as the prevailing view that livestock farming – which takes up significant land area – and rewilding are fundamentally incompatible. There has been a move towards viewing rewilding as the development of self-sustaining, self-organising, resilient ecosystems shaped by natural processes with minimal human intervention at a variety of scales – rather than creating large “cores” completely free from human interference where keystone carnivores could be reintroduced, as per conceptualisations of rewilding that were developed in the 1990s. Yet agreed definitions of what rewilding means today are still lacking.

In the context of action towards net zero, for carbon accounting purposes a precise definition of rewilding, along with standardised reporting, is required so that government can develop the evidence base for carbon flux and durable storage from rewilded land – ie, the amount of carbon exchanged between the land, atmosphere and biomass. The government and conservation agencies should consider the definition of rewilding being constructed by the International Union for Conservation of Nature’s Rewilding Working Group (expected by summer 2025) and develop region-specific guidance to reflect landscape responses to rewilding interventions, should that be deemed appropriate.

Current evidence gaps and high uncertainty around outcomes mean that rewilding is not represented in the UK’s emissions reduction targets, whereas conventional abatement approaches in the industrial and energy sectors can be readily modelled and are included. As a result, there is concern that rewilding, and other aligned nature-based solutions (NbS), are not explicitly considered in net zero pathways. Indeed, the Climate Change Committee in its Sixth Carbon Budget advice to the government recognises the potential for rewilding to deliver environmental benefits but is unable to include the approach in decarbonisation scenarios due to a lack of robust data on the abatement potential. Nor is an explicit role for rewilding stated in the government’s Carbon Budget Delivery Plan.

One reason for the data gap is that emissions from land rely on disparate data sources (eg, farming statistics, remote sensing and surveys), which are more challenging to compile than smokestack or tailpipe emissions. Additionally, for many habitat types (such as species-rich grassland, heathland, scrub, scattered forest, coastal sea grass and salt marsh), our understanding of the carbon flux is currently incomplete, with observations not existing over the time scale required by international carbon accounting rulesets.

How to harness net zero opportunities from rewilding

Brexit and withdrawal from the Common Agriculture Policy (CAP) has offered an opportunity for the UK administrations to develop new policies that balance food production with delivery of ecosystem services. There are post-Brexit policies in all the administrations that focus on sustainable land use and nature recovery, with targets for restoration of defined priority species and habitats alongside agricultural support that provides extra incentives for environmental improvements. These new approaches to subsidy payments increasingly take a “public money for public goods” approach. However, rewilding does not explicitly feature in any post-CAP agri-environmental policies, although in England the Landscape Recovery Scheme (LRS) within the Environmental Land Management scheme has goals somewhat commensurate with the concept.

The bulk of economy-wide abatement needs to come from decarbonising transport, energy and industry, but rewilding can contribute a small but meaningful amount of emissions abatement in pursuit of net zero if projects are sited appropriately. For example, by restoring degraded peatland that has been intensively farmed but where food production is not adversely impacted. If the government wishes to recognise the sequestration potential of rewilded habitats, then the identified evidence gaps and how rewilding data is managed need to be addressed, through standardised data collection and management in addition to education outreach and skills development for land managers to access post-CAP agri-environmental subsidies. Policymakers and researchers should prioritise improving the evidence base for carbon flux from rewilded land, and ensure its inclusion in decarbonisation and greenhouse gas removal strategies for agriculture and land sectors. The government should also update categories in the Greenhouse Gas Inventory to account for land use change aligned with ecosystem restoration and conservation, facilitating the reporting of rewilding-related actions.

Of course, multiple pressures on land from continued food production, renewable energy and infrastructure must be balanced. Any rewilding transition should begin in areas where it is most suited – that is where there is demonstrable community support, ecosystem degradation and low calorific output were the land to be farmed. Highly productive areas of farmland that do not have any major adverse environmental impact should not be extensively rewilded. Where there are viable opportunities, the government needs to ensure agri-environmental incentives, including for rewilding, are equitable for rural communities, and promote landscape connectivity in all regions and habitats.

Read the full report: “Exploring the carbon sequestration potential of rewilding in the UK: policy and data needs to support net zero” by Leo Mercer and Ruth Gregg (published November 2023).

The views in this commentary are those of the author and do not necessarily represent those of the Grantham Research Institute. Commentary edited by Georgina Kyriacou.

This commentary was co-published with the LSE British Politics and Policy blog.

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