Multifunctional Green Belts: A planning policy assessment of Green Belts wider functions in England

In England, Green Belt policy primarily aims to prevent urban sprawl and maintain openness. This contrasts globally with a new generation of multi-goal Green Belts which contribute to climate action and ecosystem services provision. Recently, there have been calls from researchers and practitioners for England to follow suit and widen the scope of Green Belts to provide multifunctional benefits around towns and cities. Although some secondary objectives to encourage wider benefits of Green Belt exist in English national planning policy, it is unclear if, and how, these objectives are implemented by planning authorities. Responding to this research and policy gap, this paper assesses the extent to which Green Belt policy in England promotes multifunctional benefits for people and nature. A bespoke multi-criteria policy assessment framework was designed and used on a purposive sample of 69 planning authorities across England, reflecting different governance structures and urban, peri-urban and rural locations. The results show there is considerable variation in the way benefits from Green Belts are promoted in planning policy, which can be categorised into four typologies. Where policies score high for coverage, they often had weak policy wording. Assessment criteria for protecting natural capital across scales scored highest, whilst multifunctionality, mainstreaming of ecosystem services and equitable policy delivery scored lowest of the criteria overall. Key policy hooks identified which increase assessment scores include Green Infrastructure and regional tier of government. Additionally, our results echo international literature suggesting the importance of a regional tier of government in catalysing more ambitious Green Belt policy. Whereas, some local and regional authorities perceive and treat Green Belts as positive natural capital assets capable of providing multifunctional benefits to people, their full potential has not yet been fully realised or mainstreamed in English planning policy.


Introduction
Since their inception in the early 20 th century, Green Belts (GBs) are perhaps one of the most widely known, yet contentious planning policies in the public realm.They have been described as a "powerful brand name that garners broad support, often without a deep understanding of its role and function" (Bishop et al., 2020, p. 156), with their endurance attributed to their simplicity (Taylor, 2019).In their most basic iterations, they are urban growth management policies (UGMPs) which are designated as a zone where urban land-uses are prohibited and therefore, at least in theory, separated from rural land-use (Amati, 2008).
However, in reality, the landscapes they cover are peri-urban, complex and often underutilised landscapes which are the product of the interplay between myriad processes and drivers (Scott et al., 2013;Shaw et al., 2020).Internationally, the GB approach to growth management has evolved and diverged, alongside comparable policies such as Green Wedges and Urban Growth Boundaries, as well as in different spatial and land-use planning systems, political contexts and social climates (Amati, 2008;Kirby et al., 2023).
Despite the reported success of GBs in preventing urban sprawl (Pourtaherian & Jaeger, 2022), there has been calls from researchers, practitioners and politicians for the improved mainstreaming of nature in GBs to deliver multifunctional land-use and associated benefits to society, especially in England (Amati & Taylor, 2010;Bishop et al., 2020;Campaign to Protect Rural England & Natural England, 2010;House of Lords, 2022;Kirby et al., 2023;Mace, 2018;Taylor, 2019;Thomas & Littlewood, 2010;Thrift, 2022), boosted by the urgency of the climate and biodiversity emergencies.In some parts of the world this ambition is already a reality, where a new generation of GBs have evolved beyond UGMPs and are characterised by multiple objectives including climate mitigation/adaptation, economic development, ecosystem services and regional identity (Macdonald et al., 2021).Indeed, a recent review showed that internationally GBs provide a wide range of unintended beneficial functions and effects to people beyond growth management (Kirby et al., 2023).
England is one such country where GB policy does not have formal purposes to improve quality and functions of the land it covers, instead acting as blanket policies to prevent sprawl (Amati & Taylor, 2010).However, wider benefits are encouraged in the National Planning Policy Framework1 (NPPF) as secondary considerations (MHCLG, 2021).Previous research has also shown GBs in London were implemented for broader and diverging reasons (Amati & Yokohari, 2006) and much of the public support for the GB was the result of functions other than its formal purposes (Elson et al., 1993).Developing and testing a bespoke policy assessment tool, this paper seeks to establish the extent to which English planning authorities are designing planning policies to promote wider functions in the GB, and in doing so, gain a better understanding of how nature and multifunctional land-use may be better promoted in and through English GB policy.Such assessments of policies can also aid in understanding the limitations of policies, especially when best performing policies are identified (Hislop et al., 2019).

English Green Belts: The Policy Context
GB policy, as known today is widely regarded to have originated from around London in the early 20 th Century (Bishop et al., 2020) evolving from Ebenezer Howard's Garden Cities (Howard, 1902) and later in Abercrombie's post-war London Plan (Abercrombie, 1944).In 1955 the basic principle behind GBs were formed in national policy, which saw their implementation outside London (Ministry of Housing and Local Government, 1955) and implemented through a plan-led approach regionally and locally.Historically the detailed assessment of such land-use is a neglected area (Murdoch et al., 1999).Some research has investigated the wider policy objectives and wording of English GBs, summarised in Table 1; the scope of which is mostly regional focused not nationally.Notable works include research on different local authority (LA) policy objectives for GBs throughout Greater London (Amati & Yokohari, 2006), the political discourses for GB policy in Liverpool (Dockerill & Sturzaker, 2020), and the development control of GB (Gant et al., 2011).GB policy has "baked in" arguments about limiting urban sprawl and resentment to growth resulting in a policy challenge during housing shortages.Gant et al. (2011) Greater London (UK) A detailed case study of the London Metropolitan GB, including analysis of planning registers to establish land-use change.
Long-term trends in GB land-use change linked to the development controls.GB policy does not guarantee landscape requiring additional plans.

West Midlands (UK)
Studies the extent to which GB is still seen as a regional concept by West Midlands stakeholders.
Institutional theory shows that planners and campaigners maintain that GB as being regionally and strategically important to its vision.Han & Go (2019) UK, Canada, Australia, US and Korea Explored why different countries have achieved varied levels of GB policy implementation.
Case studies across a spectrum of state-controlled growth control and decentralised privatisation shows political and social regimes have impact the uptake and success.Mace (2018) Greater London (UK) Approaches the London GB as an 'policy institution' to Identified rationalist and normative traditions to why stakeholders treat GB understand how it might be changed.
as an institution.Presents the idea for a "one off" strategic urban extension.2022).However, to date, no academic research has been undertaken to understand how these hooks and wider beneficial uses of GBs are incorporated and implemented in English LA plans.Therefore, our paper addresses this policy and research gap by adapting a tool (Scott & Hislop, 2020) originally for green infrastructure (GI) to create a multi-criteria GB policy assessment tool where a purposive selection of English planning authorities plans are assessed to establish; what extent does GB policy in England promote the enhancement of GB zones for nature, people and multifunctionality."once Green Belts have been defined, local planning authorities should plan positively to enhance their beneficial use, such as looking for opportunities to provide access; to provide opportunities for outdoor sport and recreation; to retain and enhance landscapes, visual amenity and biodiversity; or to improve damaged and derelict land" (MHCLG, 2021, p. 43) Local authorities "should also set out ways in which the impact of removing land from the Green Belt can be offset through compensatory improvements to the environmental quality and accessibility of remaining Green Belt land" (MHCLG, 2021, p. 42).

Planning Practice Guidance (2019):
"Where it has been demonstrated that it is necessary to release Green Belt land for development, strategic policy-making authorities should set out policies for compensatory improvements to the environmental quality and accessibility of the remaining Green Belt land…including those set out in local strategies, and could for instance include: -new or enhanced green infrastructure; -woodland planting; -landscape and visual enhancements (beyond those needed to mitigate the immediate impacts of the proposal); -improvements to biodiversity, habitat connectivity and natural capital; -new or enhanced walking and cycle routes; and -improved access to new, enhanced or existing recreational and playing field provision" (MHCLG, 2019, para.002)

Levelling Up White Paper (2022):
"The UK Government will develop plans for: a. further greening the Green Belt in England; "greening the Green Belt" and "enhancing and maintaining protection of the Green Belt" (DLUHC, 2022, p. 211).

Multifunctional Green Belts -Key Concepts
Central to the presented GB policy assessment are several key socio-ecological concepts including: natural capital (NC), ecosystem services (ES) and multifunctionality, as well as policy mainstreaming.NC is defined as the "part of nature which directly or indirectly underpins value to people, including ecosystems, species, freshwater, soils, minerals, the air and oceans, as well as natural processes and functions" (Natural Capital Committee, 2019, p. 3).The NC approach is championed by multiple national (e.g.UK), regional (e.g.Greater Manchester), and international (e.g.EU) institutions.ES are linked to NC and are the "the ecological characteristics, functions, or processes that directly or indirectly contribute to human wellbeing: that is, the benefits that people derive from functioning ecosystems" (Costanza et al., 2017).Importantly many functions and benefits provided in GB zones can be translated into the ES categories (Kirby et al., 2023).The ability of land to deliver several such functions is known as multifunctionality, defined more specifically as "the capacity of a landscape or ecosystem to provide multiple socio-economic and ecological benefits to society" (Hölting et al., 2019, p. 226).The use of these concepts underpins a more holistic understanding and vision for how landscapes can be beneficially used.The explicit need for multifunctionality is driven by the increasing intensification of land for production which reduces the diversity of functions they provide (EEA, 2017).
Whereas NC and ES have been widely researched and quantified more generally (Albert et al., 2016), there has been less attention given to their use to understand areas of policy deficiencies for nature.However, some notable exceptions do exist (Kieslich & Salles, 2021;Ransom & Scott, 2020;Scott & Hislop, 2020;Uittenbroek, 2016).Here the concept of "mainstreaming" defined as an "interdisciplinary and transdisciplinary endeavour of normalising an idea from one policy domain into the decision-making and routine activities of other policy domains necessary for effective delivery over the long term" (Scott et al., 2021) is important.The growing body of literature around "mainstreaming" nature into policy (Ronchi, 2018;Scott et al., 2018Scott et al., , 2021) ) shows the importance of embedding key concepts such as ES, multifunctional and place-based approaches in planning policy outside environmental chapters.One such example for practice, arising from a transdisciplinary research effort is the "Building with Nature" Framework; the first UK benchmark to deliver high-quality GI in developments where it champions the importance of place-based and equitable approaches to embedding nature in planning policy and practice (Building with Nature, 2021; Jerome et al., 2019).

Methodology
Content analysis has increasingly been applied to environmental policy topics (Hall & Steiner, 2020;Jaligot & Chenal, 2019), including multi-criteria policy assessments used to establish the effectiveness and scope of environmental policies (Jaligot & Chenal, 2019;McWilliam et al., 2015;Oulahen et al., 2018).To answer our research question, we employed a multi-criteria content analysis approach, in combination with a bespoke excel-based GB policy assessment tool, which scored policies from a purposive sample of development plans with respect to the degree of coverage across the assessment criteria, and associated strength of policy wording.This approach and tool were adapted and modified from the "Green Infrastructure Policy Assessment Tool" (Hislop et al., 2019;Scott & Hislop, 2020), which has been effectively adapted and applied to other environmental planning policy topics (Ransom & Scott, 2020).

Planning Authorities Assessed
In England 183 Local Authorities (LAs) have designated GBs (DLUHC, 2021), covering 12.5 % of England's landmass, as shown in Figure 1.A purposive sample of 67 LAs (37% of all GB LAs) were selected for the assessment, as shown in Figure 2. The selection was based on different (1) LA models3 , (2) LA typology4 (Lord et al., 2020), (3) change in boundary since 2012 and (4) LAs regional planned.See Appendix 1 (supplementary materials) for further details.As the policy assessment was part of a wider research project looking at the North-East, these LAs were also included in the assessment.To have a workable but varied sample of LAs, where possible, two LAs from each "group" were selected; one whose GB boundaries has changed since 2012 5 and one which had not, as shown in Figure 2. Selection was further refined based on having a varied geographical distribution and those LAs with the largest changes to GB boundaries.In addition, the Greater London Authority (GLA) and Greater Manchester Combined Authority (GMCA) were included in the sample to explore the differences and role of regional governance frameworks and plans.Therefore, the LAs which overlapped within these planning areas were also included.
5 2012 was the year National Planning Policy Framework (NPPF) was published and set the basis of all new and recently adopted Local Plans.Changes to boundaries were derived from annual GB statistics (DLUHC, 2021).Relevant planning policy documents suitable for assessing were then retrieved from the 67 LA and 2 Regional Authority websites.As adopted up-to-date plans were not available for many of the LAs assessed, due to the timeframes for plans to be produced in England, a pragmatic approach was taken to include plans released through the production period, including: preferred options, draft, publication, and adoption stages.Respective plan evidence bases were also screened for any relevant supplementary or supporting planning documents.
Key word searches for "Green Belt" and "Greenbelt" aided identification of relevant policies and supporting text for the assessments, however, all plans were read and coded manually.

Policy Assessment Tool
The assessment criteria which formed the foundation of the policy assessment tool was developed from (1) key concepts in the academic literature (section 1.2) that demonstrate the benefits to people from nature, (2) industry best-practice such as Building With Nature (Building with Nature, 2021), and the (3) academic discourse around more multifunctional and environmentally productive GBs (section 1), much of which build on a new generation of international GBs with broader policy objectives (Amati & Taylor, 2010;Macdonald et al., 2021;Taylor, 2019).Mapping of the literature to the criteria can be found in Appendix 2 (supplementary materials).This resulted in five main categories ( 1 developed within these groups, as outlined fully in Figure 3. Following the approach outlined by Hislop et al. (2019) and Scott & Hislop (2020), the policy assessment tool scores both the extent to which policies cover the assessment criteria and the strength of policy wording.A simple 0-3 scale is used (Figure 4).Policy coverage relates to the degree to which the assessment criteria is contained in the policy, and is scored as 0= none, 1=some, 2=most and 3=full, as shown in Figure 4. Policy strength accesses the required degree of compliance with a policy.Strength of policy wording is ranked 0=none, 1=weak, 2=medium and 3=strong, also shown in Figure 4. Importantly the strength of policy wording cannot score higher than the policy coverage score.
Strength of wording is scored based on the words used in a policy or policies that encourage or require compliance.Common words used include 'may', 'should', "encouraged', 'must', 'avoid' and 'shall not be permitted' (Hislop et al., 2019;McWilliam et al., 2015;Ransom & Scott, 2020).Words such as "should" hold less strength, than words like "must" for example, which denotes a non-optional requirement to comply.These differences are reflected by the scoring.The assessment required the interpretation of the criteria in relation to the respective policies.
Like many forms of qualitative analysis, there is a level of subjectivity, which can result in inconsistencies towards assessments (Holloway & Todres, 2003).Therefore, steps were taken to reduce subjectivity and inconsistency in the assessment.First, a scoring guide was developed to limit inconsistency in applying the criteria.For example, this established explicit and implicit references to ES to be scored the same.This is important as research shows planning has historically accounted for the benefits from nature which are now termed "ecosystem services" without explicit mention of the terms (Wilkinson et al., 2013).The guidance document was further refined through a testing and piloting stage on a sample of 10 plans resulting in further sub-division of some criteria groups and wording.Secondly, to improve consistency and validity of the method, additional policy assessors from research and practice were recruited.Here a 15% sub-set of the plans were assessed by other assessors not directly involved in the design of the criteria.Scores were then compared, and inconsistencies resolved between the assessors.Importantly, this resulted in an agreed consensus to interpreting and applying the criteria, and further refined the assessment guide.
See Appendix 1 for more details.
For each policy document assessed, the initial content analysis of policy documents was done in QSR Nvivo where coverage criteria and strength scores were coded as nodes against relative scores.Assessment worksheets were created for each policy document in the excel based tool and subdivided by chapter or section.Scores were then recorded for relevant policies in each chapter and a copy of the policy wording assessed recorded in the sheet as notes per respective scoring cells.See Appendix 3 for an example scoring sheet.Coverage and strength scores were aggregated in the tool to produce an overall policy score and percentage score.An illustrated example of an assessed and scored policy is shown below in Figure 5. 3 Results

Overview
In total 67 LA plans, and 2 Regional level plans throughout England were assessed in relation to the wider functions and beneficial use of GBs. Figure 6 below provides a spatial overview of the overall percentage coverage and strength scores for the plans assessed.A full list of scores per respective sub-criteria for each document can be found in Appendix 4. Overall, there was a surprising level of variation between policies and authorities assessed.As shown on Figure 6, there was considerable variation in coverage scores of the authorities assessed, ranging from 0-58% with a median score of 31% and standard deviation of 13%.Policy strength scores also varied, although to a lesser extent than coverage, ranging from 0-44% with a median score of 24% and standard deviation of 10% (Figure 6).The two regional plans assessed scored well above average (Greater Manchester Combined Authority =47% coverage & 36% strength; Greater London Authority =58% coverage and 40% strength), and those LAs whose plans were required to take account of the regional plans or developed alongside them also scored above average for coverage.Plans which scored higher on coverage, often score proportionally lower on strength, when compared with lower scoring plans on coverage, which often had less variation between coverage and strength scores.Interestingly, some LAs such as Newham scored 0% (coverage & strength) with no relevant GB policy identified in their 2018 adopted Local Plan.Likewise, several LAs (Stoke-on-Trent, West Oxfordshire, Manchester City, Greenwich, and Southend-on-Sea) also scored very low (below 10%) due to their plans having very little coverage of the GB assessment criteria.It is important to stress that the assessment tool does not assess the efficacy of GB policy in relation to its primary growth management purpose.
The planning policy documents assessed ranged from 2012-2022.Therefore, as stated in section 2.1, plans at all stages of production were considered where appropriate.It is notable that some "preferred options" plan scored high on coverage, but low on strength due to detailed policy strength wording not being fully developed at this stage.Thus, the results should not be used to rank or compare local authorities against each other, but instead understand how, if, and to what extent different planning authorities promote wider benefits through GB policy and identify best practice at a moment in time.Additionally, it is important to stress that promoting such benefits through GBs is of secondary priority to the five GB purposes (MHCLG, 2021).Therefore, these scores are not reflective of GB policy implementation more broadly.

Sub-Criteria Variation
Of the plans assessed, no single plan had complete coverage (or strength) scores at either the "full" "most" or "some" levels across the suite of assessment sub-criteria (Appendix 4), meaning every plan has gaps in coverage.However, a complete set of coverage scores, combining the highest score across the sub-criteria from all plans is show in Figure 7.In addition to showing the highest coverage scored for each sub-criteria, Figure 7 also shows the corresponding number of plans which achieved that sub-criteria coverage score.Figure 8 shows the mean combined coverage and strength scores derived per each sub-criteria from 69 plans assessed.As with the overall scores Figure 8 shows that, on average, policy strength scored lower than coverage scores.It was also found that there are also a wide and uneven variations in coverage and strength scores across the 15 sub-criteria, as shown in Figure 8.
These differences in the criteria and sub-criteria scores are reported in more detail in the following sub-sections.

Mainstreaming
The "mainstreaming" criteria were the lowest scoring of all the criteria, both in terms of coverage and strength of policy wording.The sub-criteria "Ecosystem Services & Natural Capital Concept" scored a maximum score of "most" in two policy documents and had the lowest average coverage of any sub-criteria scoring 0.12 out of 3, showing it was rare for concepts such as ES or NC to be explicitly or implicitly associated or linked to GBs in our sample.Likewise, the sub-criteria "Cross-Sector Integration & Benefits of GB" also scored an average of 0.13 out of 3 and was the second lowest score of all sub-criteria.The beneficial role of GB as a natural asset was almost never acknowledged outside of GB or natural environment chapters of the plans.However, one example of making a wider cross-sector link was: "The Green Belt makes up a considerable proportion of land in the Plan area, and it is therefore vital that its various parts play a beneficial role that supports the environmental, social and economic wellbeing of the city-region's residents" (GMCA, 2021, Here, whereas neither NC or ES were explicitly mentioned, the wording implicitly describes these concepts and wider sectoral benefits.For both sub-criteria, average policy strength scores were even lower, showing that in the limited examples there was some coverage, it did not have comparable policy strength.

Protection & Enhancement
The "protection & enhancement" criteria was the highest scoring group on average amongst the plans assessed.The sub-criteria "protects natural capital" was the third highest scoring on average of all sub-criteria, with 26 of the plans assessed scoring "full", showing that plans often considered and made provision for the protection of GBs in policy.Positively, "protects natural capital" scored highest of all sub-criteria on policy strength, scoring 2 out of 3 on average, showing that the protection of GB was given the highest weighted policy strength comparatively of the sub-criteria assessed.Whereas not scoring as high: "Enhances and Manages Natural Capital" scored an average of 1.44 out of 3, showing the enhancement of GB was considered in many plans.However, enhancement was often referenced in relation to requirements for "compensatory improvement" (see table 2), which reduced the scores for these sub-criteria6 .Compensatory improvement policies differed in their degree of coverage.
For example, one of the higher scoring policies was: "Proposals that will enhance the beneficial use of the Green Belt and/or will provide opportunities to mitigate or provide compensation enhancements against losses to Green Belt, will be supported... Particular proposals include those that encourage healthy lifestyles… improve access as part of Trafford's Green Infrastructure Network and create and improve habitats, including…through biodiversity net gain."(Trafford Council, 2021, p. 121).Others, such as Solihull MBC (2021) provided a hierarchy of how compensatory improvement might be met including firstly within close proximity to development, then settlement area, GI opportunity mapping, and finally through developer contributions.Higher scores for policy strength of this sub-criteria were associated with requirements for loss of GB to be compensated with enhancement, and only two plans scored "full" on coverage and strength.
Those plans which encouraged the enhancement of GB independent of any compensatory loss scored higher, as shown by 9 plans which score "full" for this sub-criteria.For example, "The Council will work proactively with developers, and landowners to enhance the beneficial uses of the Green Belt" (Central Bedfordshire Council, 2021, p. 103) and "the Plan seeks to ensure that the Green Belt rural economy can thrive…and aims to add value to Green Belt areas as a resource for visitors…Proposals that support a positive use in the Green Belt will be encouraged" (Northumberland CC, 2019, p. 48).

Ecosystem Services & Benefits
The "ecosystem services & benefit" group was the third lowest scoring of the criteria groups.
However, there was variation in the degree to which plans acknowledged the sub-criteria in relation to GBs.Cultural services were the most covered, scoring an average of 1.17 out of 3, with 22 plans achieving "most" coverage.The most common cultural ES mentioned in plans were recreational and visual amenity benefits.Less frequently reported cultural services where health and wellbeing benefits."Ecosystem Functioning" was the second most covered sub-criteria in the group scoring 0.64 out of 3 on average.It was common for plans to acknowledge the contributions of GB to biodiversity, however, less common for plans to identify functions such as habitat connectivity, reflected in only 3 plans scoring "most".
Provisioning services scored an average of 0.45 out of 3 for coverage, often being linked to provision of agriculture or forestry infrastructure, but rarely linking the benefits of agriculture or forestry themselves.One exception was "…. the potential use of the land [GB] for food production or community gardening" (Harrow Council, 2013, p. 52).Regulating services were the least promoted of the sub-criteria scoring an average of 0.23 out of 3 for coverage.
However, one plan did score "full", recognising a range of regulating services from GB, notably, flood regulation, temperature regulation and carbon sequestration.For example Redbridge acknowledge GB, "play an important role in helping to control flood risk and mitigating the risks of climate change" (Redbridge, 2018, p. 137) and"…performs multiple beneficial functions for London, such as combating the urban heat island effect" (Mayor of London, 2021, p. 315).Across all these sub-criteria, strength scores were low, reflecting the way most plans recognised these benefits, but didn't actively encourage their provision in policies.

Multifunctionality
The "multifunctional" criteria group was the second lowest scoring on average.Specifically, the sub-criteria "promoting multifunctional land-use" scored an average of 0.61 out of 3 and only 2 plans assessed scored "full".However, in some plans that did promote multifunctionality, GI was used as a common policy hook, as well as linking with the wider "enhance and manage…" sub-criteria.One example of a policy was: "…the potential to deliver additional green infrastructure benefits is particularly significant, and increasing public access will be an important way of ensuring that all residents are able to directly benefit from the Green Belt" (Salford City Council, 2020, p. 193).The explicit use of the term "multifunctionality" regarding GB was less common but not fully absent from the assessed plans.For example: "...the enhancement of the Green Belt to provide appropriate multi-functional beneficial uses for Londoners should be supported" (Mayor of London, 2021, p. 314).The "integrated issues" sub-criteria scored comparably less on average, with few examples of linking biodiversity, climate and health agendas through GB, and when this did, for example the one plan which score "full", it rarely backed up with weight to policy wording.

Context & Extent
The final criteria group "Policy Extent & Context" contained the first and second highest average coverage scores from the "urban growth management policy" and "site scale" subcriteria respectively.This is perhaps not surprising given 53 assessed plans scored "full" for the former, attributed to having dedicated GB policies.This was also reflected in the relatively high scoring of policy strength.However, it was less common for policies to fully consider the wider landscape scale deliverability of GB, but nearly all did consider this to "some" degree as reflected in the 1.83 out of 3 average score.For example, it was common for policies to say: "Maintain a strong rural landscape character by retaining the physical separation, setting, scale and character of rural villages" (Pendle BC, 2021, p. 38).
The "context and place-based" sub-criteria scored an average of 0.57 out of 3, with a shortage of plans seeking to use GB to address specific local issues.An exception was the in Durham CC (2020, p. 65) which mentioned "deal with any existing environmental issues" with regards to prioritising compensatory improvement.However, it was more common for plans to acknowledge the contributions of GB to wider setting and character.The fourth least covered sub-criteria were "social equitable" scoring 0.15 in coverage and 0.10 (out of 3) in strength.Very few plans considered how GB policies, may be delivered in an equitable way and address issues such as greenspace inequality.Reflected in only one plan scoring "most".
An example of linking GB to green space deficiency was identified in Luton Council (2017, p. 28) "Luton's Green Belt also provides a secondary purpose for beneficial uses such as amenity for the urban population and providing opportunities for…informal high quality outdoor recreation and green space, which is lacking in Luton".However, even here the policy does not state that GB policy should target those which who have least access to greenspace.

Discussion
The results show that across the plans assessed, there is considerable variation in the way benefits from GBs are acknowledged and promoted in English planning policy, including how those functions are promoted in national planning policy.This is surprising given the way national policy tries to ensure consistency in approach.Ultimately, the results suggest that whilst some LAs seek to promote the beneficial use of GBs in England, they are largely underutilised in planning policy as mechanism to promote land-use which benefits people and nature.Therefore, GB policy in England is currently a neglected opportunity space for promoting multifunctional land-use.Given this variation as a point of departure, our findings raise two key questions which form the basis of our discussion; (1) Why is there such variation, and why do some authorities go beyond what is expected whilst others do not?and (2) How can barriers be overcome to mainstream nature and multifunctionality in GB policy?

Barriers and variation in Green Belt policy amongst planning authorities
The variation identified in our assessment is consistent with the limited body of previous policy research on GBs, including in the London Metropolitan GB, where a number of different policy priorities for GB were shown to exist amongst local authorities, including GB as enhancing and improving landscape protection (Amati & Yokohari, 2006), much of which is still mirrored in our results today, and extends across England.Likewise, internationally, the policy implementation of the Portland Urban Growth Boundary has been shown to also be implemented differently, including delivering and embedding ES (Woodruff & BenDor, 2016).Similarly, in the Greater Golden Horseshoe (GGH) GB in Ontario, inconsistency in municipal GB policy implementation was found to affect delivery of the regional GB policy goals (Macdonald et al., 2021).Our findings also have parallels to other environmental policy assessments in the literature which also found local authority GI policies were highly variable when assessed collectively (Hislop et al., 2019).
Based on the variation found in our results, a typology of how planning authorities incorporate the beneficial use of GB is proposed and outlined in Table 3.Here the assessed planning authorities fall into at least one typology: 1) Develop some Green Belt, 2) Develop and enhance, 3) Protect Green Belt, 4) Protect and enhance.Here planning authorities are shown to perceive GB benefits in different ways, including the degree beneficial use of GB is promoted.In the "Develop Green Belt" typology, a key policy gap was identified in many GB policies, in that several recently produced plans which released GB for development did not include a policy requiring or encouraging compensatory improvement of GB as promoted in the NPPF (MHCLG, 2021, para. 142).
Table 3: A typology of the beneficial use of green belt in planning including example authorities from the policy assessment.

Typology Description Example Authorities 1) Develop some Green Belt
These planning authorities scored low on coverage and strength, with little to no coverage of the beneficial use of green belt.This typology used the local plan making process to review the green belt boundary and accommodate development without compensatory improvement of remaining Green Belt.

Manchester City
Greenwich Gateshead Lancaster West Oxfordshire

2) Develop & Enhance some Green Belt
Like type 1 they used the local plan making process to review green belt boundaries and develop growth but used this as a catalysis to acknowledge wider benefit of Green Belt and require future enhancement, through compensatory improvement.Often linking to concepts such as green infrastructure networks.

3) Protect Green Belt
Green Belt is left mostly unchanged.These local authorities have good coverage and strength on protection of green belt, but have low to no coverage of enhancement, multifunctionality and promoting ecosystem services.Thereby, protecting but not actively promoting the enhancement.
Elmbridge Guildford Cheshire East Hillingdon Pendle

4) Protect & Enhance Green Belt
Like "protect Green Belt" these planning authorities scored high on protection policies and did not seek to use the local plan process to amend Green Belt.However, they actively seek to enhance the beneficial use of Green Belt, regardless of development, scoring higher on many of the criteria groups including multifunctionality and responding to local contexts and needs.

Central Bedfordshire Harrow Hounslow Northumberland
Whereas the research method does not allow specific contextual barriers to higher scoring GB policies, and reasons for this variation to be identified, it is important to discuss and suggest possible barriers and limitations, in order to understand how the wider benefits of GB can be mainstreamed in future English policy using hooks and bridge (section 4.2).General barriers are proposed and shown in Figure 9. Firstly, and perhaps most obvious limitation was the relative weakness of the strength of policy wording.Notably research on the strength of policy wording is scarce compared to policy coverage, but our results reflect findings of other UK environmental policy assessments in regards to overall comparatively weak policy wording (Hislop et al., 2019;Scott & Hislop, 2020).In our assessment ambitious examples of GB policy are rarely backed up with strong wording.In Canada, environmental policy analysis highlighted weak and vague policy wording (McWilliam et al., 2015) as well as the lack of regulatory mandate to implement ES in planning as a barrier to strong wording (Kerr et al., 2021).Conversely, analysis of GI planning across Scandinavia found mixed coverage, but multiple policies and strategies with strong wording (Nordh & Olafsson, 2021).This is important because without strong policy wording, GB policies to promote wider functions may not materialise into positive enhancement on the ground, therefore requiring an ambition to go beyond what is required, or stronger weight to GB policy.
Furthermore, there may be several explanations, or barriers which explain the variation and diversity of approaches found in our results.As mentioned, compared with other international GBs (Amati & Taylor, 2010), English GBs are not formally required to provide these beneficial functions.Thus, planners and local politicians will differ in policy priorities depending on how the GB is perceived and other relevant policy hooks.These decisions are likely results of several interrelated factors, including politics, and context as key potential barriers.Firstly, GBs cover a wide variety of landscapes across England, with different degrees of existing access, habitat types and interventions to improve the landscapes (Campaign to Protect Rural England & Natural England, 2010).Therefore, it is likely that existing perceptions of GB differ contextually across England.GB is also a highly contentious policy area, which the general public have strong attachment too (Bradley, 2019;Goode, 2022b), and as such they are politically charged and sensitive to local politicians (Dockerill & Sturzaker, 2020).Both in England and internationally these politics affect how GB policy is applied, and is often a key barrier (Dockerill & Sturzaker, 2020;Eidelman, 2010;Mace, 2018).Indeed, resistance to GB development is enough to sway elections in many politically conservative heartlands and a topic that politicians navigate with extreme care, often resulting in polarised positions (Lund, 2015).It is argued that the development of the GGH GB in Ontario was to gain support in key peri-urban electoral districts (Eidelman, 2010).Therefore, the importance of leadership and political buy in to mainstream nature in such policies is key to overcoming barriers (Scott et al., 2018).
More broadly other barriers may help explain the variations in results.Even though NC is of cross-cutting relevance across government (Maes et al., 2020) the environmental agenda is still not effectively mainstreamed into wider planning policy (Scott et al., 2018).This is due in part, to the complex pathways required, problems in their wider communication and understanding, and silo mentality that pervades much of planning policy (Scott et al., 2021).
In addition, different environmental concepts have been subject to their own separate mainstreaming efforts, such as GI (Hislop et al., 2019) and NC (Defra, 2018) which themselves are not effectively mainstreamed.Thus, mainstreaming nature in GBs may still be at the beginning of its own journey requiring more integration with NC, ES and GI, to overcome this barrier.Here the concept of socio-ecological systems may help unite these concepts together and in the context of GB (Colding & Barthel, 2019).Our results show some encouraging evidence of some LPA overcoming this barrier, with links between GI and GB in higher scoring plans.Additionally, Scott et al (2021) emphasise the need for transdisciplinary efforts from the start using key hooks to build traction with audiences outside the environmental camp.Furthermore, contextually there is a wider policy and research neglect of peri-urban landscape, which GB in part cover.Further research to better understand the potential institutional, political and knowledge barrier suggested, merits attention.

Overcoming barriers to mainstream Green Belts policy
Given the intended and unintended benefits and functions of GBs internationally (Kirby et al., 2023) and the discussed variations in approach in English GB policy, as well as potential barriers, it is pertinent to explore how such benefits may be overcome to mainstream benefits more widely in English GB policy.Here two important concepts are policy "hooks" and "bridges"."Policy hooks" describe a link to a key policy, legislative term, duty or priority that relate to a particular group, whereas "policy bridges" are similar to "hooks", instead they link terms, concepts or policy priorities that are used and understood across multiple groups and publics (Scott et al., 2018).Hooks and Bridge act as key mechanisms to overcome several of the barriers outlined in section 4.1.

Green Belt Policy Hooks
Multiple policy hooks exist to mainstream the beneficial use of GBs.Firstly, as highlighted in the results, GI is a key policy hook with some authorities seeing GB as a multifunctional asset within the wider GI network.However, we argue that the wider reluctance to frame GB as part of the GI network is a key barrier which seriously hinders the wider multifunctional objectives of GB at present.Thomas & Littlewood (2010) proposed early in the inception of GI its potential to contribute and link to GBs, an idea which was gaining momentum at the regional level through spatial strategies before their abolishment in 2010 by the then government.Indeed, other research suggest that this strategic GB vision still holds importance for planners (Goode, 2022a) and even informal regional visions can be powerful, as seen in the longevity of the Copenhagen Finger Plan in Denmark (Vejre et al., 2007).This is especially relevant given our results that suggest the existence of a strategic tier to planning (GMCA & GLA) may be an important factor in higher scoring plans.The regional tier may also reduce political tensions and cross-border issues as seen in the Portland Metro (Thiers et al., 2018).Therefore, in widening the functions of GB policy, planners may wish to look at the new generation of GB policies internationally, where it is argued that without effective and joined up regional governance the ability to deliver multiple goals through GB policy is reduced (Macdonald et al., 2021).Additionally, as evidenced by Thomas & Littlewood (2010) such tier may be more receptive to policy hooks, and resilient to some of the barrier, such as local politics as discussed in 4.1.
One of the most significant hooks is the NPPF requirement that loss of GB is compensated by improvement to the environmental quality and accessibility of the remaining GB (MHCLG, 2021, para. 142) as illustrated in the typology 2 (Table 3).The implementation of this policy in local and regional plans is important as it requires planners to think about GB as a beneficial natural asset.Those local authorities which have well developed policies for compensatory improvement has also often undertaken specific studies to explore potential improvement to GB, within their local context, including Greater Manchester, Barnet, Blackburn, and Worcester.Such work is not only important for extending thinking around GB, but also provides a key resource to target locally relevant GB improvement.Planning authorities could build on this through dedicated supplementary planning guidance.
Additionally, another potential hook is the reference to "greening the green belt" as part of the pride in place section of the Levelling Up White Paper (DLUHC, 2021, p. 211), however it is unclear how this ambition may be delivered.A key catalyst and policy hook for multifunctional use of GB is the House of Lords Select Committee recommendations on Land Use for the enhancement of GB for delivering multifunctional benefits, and that it should be a central priority for England's future land use framework (House of Lords, 2022).

Green Belt Policy Bridges
Given the nexus of climate change with societal issues and disciplines it is a key policy bridge (Chiabai et al., 2018), and one which may reduce barriers such as silo working..Many ESs relating to climate change scored low in the GB assessments, but internationally zones of UGMPs including GBs have been shown to provide a range of regulating ES (Kirby et al., 2023) including in the US as important zones for sequestering carbon (Han, Daniels & Kim, 2022).Indeed, internationally climate mitigation and adaptation are considered as primary aims of the GGH GB (Taylor, 2019).As a "bridge" climate change is an issue other stakeholders can also support in relation to GB (Goode, 2022b).Such examples of comparative GB policies may themselves also act as key bridges for the English context.
Notably, north of the border in Scotland7 the recent draft planning guidance provides an example of broader GB policy, with notable differences including supporting nature networks and explicit use of GB for GI (Scottish Government, 2022).
The timing of the COVID-19 pandemic alongside increasing impacts of climate change and decline of nature provides the opportunity for transformational change at the global scale (McNeely, 2021).As such, another potential bridge is health and wellbeing; the importance of which in relation to greenspace has been illustrated in the pandemic (Labib et al., 2022).
Evidence also suggests that in light of the pandemic, strategies should seek to equalise access to green spaces (Astell-Burt & Feng, 2021).This is notable given the prominence of health in the early inception of the GB concept in England (Bishop et al., 2020) and the positive effects GB has been shown to have on human health in Korea (Jeon et al., 2020).Thrift (2022) makes the argument that the rationale GB have huge potential to improve physical and mental health, if integrated with multiple agenda holistically.
Given that compensatory improvement is dependent on development of GB, much of which is in private ownership (Campaign to Protect Rural England, 2022) and the importance of joined up plans (Taylor, 2019) and policies (Daniels, 2010) internationally for GBs, the raft of emerging environmental policies (Defra, 2018) in England may lay important bridges for delivery of GB multifunctionality.Specifically offsite Biodiversity Net Gain (BNG), Local Nature Recovery Strategies and the Environmental Land Management Schemes as summarised in Table 4. Again, supplementary planning guidance may aid in setting out how these policies may interact with GB in a place-based context.For example, habitat creation from BNG could be complemented with access improvement through GB compensatory improvement, compounded by the statutory requirements weight of BNG.And perhaps critically, opportunities to pool financial capital to deliver more ambitious interventions.
What is essential is that these policies are integrated together, rather than being delivered in separate policy silos.Currently there is little evidence of this happing (House of Lords, 2022).By including GB within the scope of LNRS, compensatory improvement can be directed to areas where they can be most beneficial Biodiversity Net Gain (BNG): Requirement for 10% gain in biodiversity in developments, ideally on-site but also off-site.
The proximity of the GBs as open space close to development means it is ideally placed as a BNG receptor.
Environmental Land Management (ELMS): agrienvironmental schemes for farmers and land managers to enter into agreements to be paid for delivering ecosystem services.
Much of green belt is agricultural land -Payment for to provide environmental improvement in the the green belt.

Model Green Belt Policy
Whereas a full scoring suite of policies was not identified across the criteria (Figure 7) an amalgamation of the best scoring policies has been developed into a 'model' secondary GB policy for English authorities (Figure 10) which incorporates the findings of our study and builds from the policy hooks and bridges needed to overcome the limitations discussed (Figure 9). .However, it is important that this is adapted to the local context, addressing key local land-use priorities and ESs in demand, opposed to a one-size-fits all policy which may result in operational challenges.

Study Limitations
Whereas this study aimed to objectively assess GB policies from the perspective of nature, multifunctionality and benefits to people, the study has several limitations.Firstly, this study assesses a purposive sample of 67 planning authorities, but 183 LAs in England have GBs, and therefore not all eligible plans were assessed.Whereas we sought to assess a broad range of plans, there may be examples of plans which score higher than those accessed in our study.Therefore, our average scores reflect the plans assessed, and are not a definitive average for all GBs policies across England.Secondly, documents which were assessed were not all at the same publication date, and range considerably over a 10-year period.Therefore, some plans did not include policies which reflected current national guidance for GBs.This means LAs should not be directly compared.Thirdly, our criteria were based on previous literature on GBs and wider concepts to account for nature in policy.Therefore, this is our interpretation of what elements a GB policy which promotes beneficial use and multifunctionality could look like, and others may agree or disagree that certain elements of the criteria are merited.Finally, whereas steps were taken to reduce subjectivity and the increase replicability of applying the criteria in the assessment, as described in section 2.2, interpretation is always required.

Conclusions
Society is experiencing climate, nature, health, and inequality tipping points, much of which comes into stark view in peri-urban areas around our towns and cities.With GB being a rare example of a policy covering much of these peri-urban landscapes in England, means they may be an important opportunity and action space to help address these challenges.Our results show that at present the wider and multiple functions of GB are not yet fully realised or mainstreamed in planning policy, and planning authorities treat and view GB differently.
Plans tended to score higher on protection of GBs and its consideration of the site scale, whereas elements such as multifunctionality, ES and social equality tended to score lower, and were less common in plans.Some higher scoring plans treat GB as more than UGMPs and show key policy hooks exist, such as GI, and requirements for GB compensatory improvement and strategic planning.Additionally, it is argued that opportunities exist through key policy bridges of health, climate change and through emerging environmental policy to realise the wider multifunctional potential of GB in England.These may help address key barriers to mainstreaming the wider benefits of GB in policy.Notably, that GB are politically and socially contentious in England, with strong pressure for parts of them to be developed, which also requires trade-offs with wider benefits.Building on current debates we agree with others that there is a need for a wider national GB conversation, to rethink its purposes (Thrift, 2022), especially around the potential need for the strategic planning of GB (Goode, 2022b), which have been successful for multifunctional GB internationally.Thereby aligning English GB with the new generation of GBs which not only protects land due in proximity to the urban area, but also promotes the functional and positive enhancement of these zones for people and society.

Figure 3 :
Figure 3: GB policy assessment criteria including categories headings, sub-categories headings and full subcriteria descriptions.

Figure 5 :
Figure 5: Example partial assessment of The Salford Publication Local Plan (Salford City Council, 2020) GB policy.

Figure 6 :
Figure6: Spatial overview of total percentage coverage and strength scores per local and regional authority assessed.Coverage scores range from 0-56%, and Strength scores range from 0-44% as represented in the respective colour gradients.For both variables plans could achieve a maximum percentage score of 100%.

Figure 7 :
Figure 7: Maximum coverage scores per induvial sub-criteria group across all plans assessed.Showing highest scores achieved across all plans cumulatively.Number of plans which achieved each respective highest score are shown in brackets.

Figure 8 :
Figure 8: a) Mean GB nature policy assessment coverage scores per each sub-criteria derived from all 67 plans assessed.b) Mean GB nature policy assessment strength scores per each sub-criteria derived from all 67 plans assessed

Figure 9 :
Figure 9: Potential general barriers and limitations to higher scoring Green Belt Policies.Barriers shown in red and often interrelated.

Figure 10 :
Figure 10: Model secondary Green Belt policy developed from best scoring policies assessed and key findings from the results.

Table 1 :
Notable English GB Policy Research The revision of Planning Policy Guidance 2 (PPG) 2 in 2001 marked a key juncture for the broadening of GB policy, as for the first-time secondary objectives for the use of GBs, including for recreation, nature conservation, agriculture, and landscape enhancement, promoted a more positive and functional vision for GBs (Office of the Deputy Prime Minister, 2001).Today GBs main aim is to still "prevent urban sprawl by keeping land permanently open"(MHCLG, 2021, p. 41).However, multiple policy hooks to promote the positive planning of GBs and their wider functions have evolved from PPG2, including in its replacement: the NPPF, shown in Table2below.This includes positive planning to enhance beneficial uses and notably, requirements for LAs who remove land from GB to provide compensatory improvement to the environmental quality of the remaining GB(MHCLG,    2021, para.142).Notably, a recent House of Lords Select Committee enquiry on land-use in England recommended GB should be used to deliver multiple benefits (House of Lords,

Table 2 :
Multifunctional English GB Policy Hooks National Planning Policy Framework (2021):

Table 4 :
Natural environment policy bridge for Green Belt Enhancement