UK natural capital accounts quality and methods guide

The UK natural capital accounts provide estimates of the financial and social value of natural resources to people in the UK. This guide provides quality and methods information for our UK natural capital accounts bulletins.

Our accounts are compiled in line with the guidelines in the United Nations (UN) System of Environmental-Economic Accounting (SEEA) Central Framework and the UN SEEA Ecosystem Accounting.

The accounts present data for:

• the total size of seven broad terrestrial habitats (extent)

• the quantity and value of services supplied from ecosystem services provided by nature on an annual basis (physical and monetary ecosystem service flow accounts)

• the value of the ecosystem services as an asset, which is the stream of services expected to be provided over the lifetime of the asset (monetary asset account)

We produce a new time series in every annual report. These should not be compared with previous years' publications on a like-for-like basis because of continuous development of and changes to our methodologies described in Section 4: How we are developing the statistics.

Our accounts feed into the extended accounts in our UK National Accounts: The Blue Book.

What the accounts cover

We publish our UK natural capital accounts annually. We provide ecosystem services estimates on a calendar-year basis, covering 16 ecosystems services. Each of these is grouped into one of three types of ecosystem service: provisioning service, regulating service, or cultural service. For each ecosystem service, we estimate physical flow, annual value, and asset value. Definitions for each ecosystem service can be found in Section 6: Definitions.

Each ecosystem service is allocated to one or more of the following eight broad habitats:

• enclosed farmland
• woodland
• mountains, moorland, and heath
• semi-natural grassland
• urban
• freshwater, wetlands, and floodplains
• coastal margins
• marine

We provide extents for the eight broad habitats. The marine extent numbers refer to where a terrestrial habitat has become marine or a marine habitat has become terrestrial over the time period.

If we are unable to allocate an ecosystem service to a habitat, this is classed as "other".

Each ecosystem service may contain unique habitat breakdowns that are particular to that ecosystem service. These breakdowns are in our UK natural capital accounts – detailed summary tables dataset.

Geographic coverage and granularity of the statistics

All ecosystem services are produced at a UK level and at a country level. This means there are estimates in our natural capital accounts that cover the UK, England, Scotland, Wales, and Northern Ireland. The exception to this is urban heat regulating, which currently only measures 11 city regions in Great Britain; there are no Northern Ireland estimates for this ecosystem service.

Data from each country are used to produce each ecosystem service's country-level estimates, unless specified in this guide. Where country-specific data are not available, these country-level estimates are imputed or estimated from the available country-level data sources.

For several ecosystem services, we calculate the country-level monetary values by subtracting the Scotland value from the UK value and apportioning the rest to England, Wales, and Northern Ireland. These are:

• agricultural biomass provisioning

• coal provisioning

• minerals and metals provisioning

• renewable electricity provisioning

• water provisioning

For oil and gas provisioning, production in Wales and Northern Ireland is assumed to be zero because there is minimal oil and gas extracted from Wales or Northern Ireland. For physical and monetary values for oil and gas provisioning, there are physical flow and monetary values for UK and Scotland. England values are assumed to be the remainder, when Scotland values are deducted from the UK value.

For recreation and aesthetic (house prices), there are only monetary values for England and Wales, from which Scotland and Northern Ireland are modelled.

Some ecosystem services are produced at a more granular level than country level, including:

• air pollution regulating physical flows, annual, and asset values, which are produced on a local authority basis

• greenhouse gas regulating physical flows, annual, and asset values, which are produced on a local authority basis

• recreation and aesthetic (house prices) annual and asset values, which are produced on an International Territorial Level 1 basis

• urban heat regulating annual and asset values are produced for 11 city/enterprise regions (which are referred to as city regions in our natural capital accounts), including Greater Manchester, Liverpool, London, North East England, Sheffield, West Midlands, West Yorkshire, West of England, Edinburgh, Glasgow, and Cardiff

Availability of statistics over time

Statistics for each ecosystem service are available from different starting points. Unless explicitly mentioned, this is the start date of physical flows, annual, and asset values.

Ecosystem services that are available from 1998 onwards:

• agricultural biomass provisioning (annual and asset values for all crops)

• coal provisioning

• minerals and metals provisioning (annual and asset values)

• oil and gas provisioning

• timber provisioning

• woodfuel provisioning

• water provisioning (annual and asset values)

• greenhouse gas regulating

• urban heat regulating

Ecosystem services that are available from 1999 onwards:

• agricultural biomass provisioning (physical flow for all breakdowns, including all crops, barley, feedstocks, grazed biomass, oats, oilseed rape, and wheat)

Ecosystem services that are available from 2002 onwards:

• water provisioning (physical flow)

Ecosystem services that are available from 2003 onwards:

• renewable electricity provisioning (physical flow)

• recreation and aesthetic (house prices)

• recreation (health benefits) – for Scotland only

Ecosystem services that are available from 2005 onwards:

• air pollution regulating

Ecosystem services that are available from 2008 onwards:

• minerals and metals provisioning (physical flow)

Ecosystem services that are available from 2009 onwards:

• recreation (health benefits) – for UK and all remaining countries

Ecosystem services that are available from 2011 onwards:

• recreation and tourism (expenditure)

Ecosystem services that are available from 2014 onwards:

• noise regulating

Ecosystem services that are available from 2016 onwards:

• fish provisioning

Where the data come from

Most of the data used within the natural capital accounts are publicly available; some are produced for and delivered to us. Individual data sources for each ecosystem service they relate to are listed in this section. Information on how they are used within our methods can be found in our UK natural capital accounts methodology guide: 2024.

Data sources used for multiple ecosystem services:

• UK input-output supply and use tables from the Office for National Statistics (ONS)

• Capital stocks and fixed capital consumption from the ONS

• Non-financial business economy datasets from the ONS Annual Business Survey

• Annual average yield from British Government Securities and 10-year nominal par yield from the Bank of England

• GDP deflators at market prices from HM Treasury (HMT)

• Green book supplementary guidance: discounting  from HMT

Agricultural biomass provisioning data sources:

• agricultural data from the Department for Environment, Food and Rural Affairs's (Defra's) Agriculture in the UK datasets

• provisional cereal and oilseed production estimates for England for regional physical flows for barley, oats, oilseed rape, and wheat from Defra

• total income from farming estimates from the Scottish Government and total income from farming in the UK from Defra; used to assign UK net capital stock for Standard Industrial Classification (SIC) 01 for Scotland based on the ratio of consumption of fixed capital between the UK and Scotland

• agricultural accounts for each nation, including total income from farming in the UK from Defra, total income from farming in England from Defra, aggregate agricultural output and income from the Welsh Government, agricultural incomes from Northern Ireland's Department of Agriculture, Environment and Rural Affairs; used to apportion the remainder of the resource rent, once Scotland has been deducted, based on the gross operating surplus

Coal provisioning data sources:

• coal production statistics in the Digest of UK Energy Statistics (DUKES) from the Department for Energy Security and Net Zero (DESNZ); this does not include Northern Ireland, which stopped coal production in 1970

Fish provisioning data sources:

• physical data on marine fish capture (live weight) from the rectangle-level landings data in the Marine Management Organisation's (MMO's) UK sea fisheries annual statistics

• spatial data from the EU Commission's Joint Research Centre Scientific, Technical, and Economic Committee for Fisheries, as part of the Fisheries Dependent Information

• stock assessments for all fish species across UK waters from the International Council for the Exploration of the Sea (ICES); used to estimate the sustainability of fishing

• economic estimates for fleet segments from Seafish

Minerals and metals provisioning data sources: 

• physical estimates of mineral extraction from the British Geological Survey (BGS)

• Indicators of house building, UK dataset from the ONS

Oil and gas provisioning data sources:

• Production and expenditure projections for physical estimates of oil and gas production and asset valuation from the North Sea Transition Authority (NSTA)

• Oil and gas statistics from the Scottish Government, which are comparable with the UK NSTA data

Renewable electricity provisioning data sources: 

• data on electricity generated by renewable sources from DESNZ's DUKES

• Energy Trends from DESNZ; used to apportion values for the four nations using the percentage of electricity generation from renewable sources

• regional renewable and non-renewable installed capacity figures from DESNZ's Regional Renewable Statistics

Timber and woodfuel provisioning data sources:

• removals estimates from Forest Research's (FR's) Timber statistics

• Coniferous Standing Sales Price Index stumpage prices from FR's Timber Price Indices 2024 publication

• FR's Forecasts of timber availability; used to estimate the pattern of expected future flows of the service over the asset lifetime

• FR's UK roundwood deliveries (ODS, 106KB); used to separate out woodfuel provisioning by deducting this data from the timber value, to ensure no double counting occurs

Water provisioning data sources:

• physical data from the Drinking Water Inspectorate, Northern Ireland Water, Scottish Water, Natural Resources Wales (NRW) and Welsh Water Dwr Cymru

• water abstraction tables from Defra for data before 2018 for England

Air pollution regulating data sources:

• atmospheric chemistry and transport model for physical flows from the European Monitoring and Evaluations Program Unified Model for the UK (EMEP4UK)

• Air Quality damage cost guidance from Defra

• A scoping study on the valuation of risks to life and health: the monetary Value of a Life year (VOLY) report from the Health and Safety Executive

Greenhouse gas regulating data sources:

• physical data relating to carbon exchange in the Land Use, Land Use Change and Forestry (LULUCF) sector from the UK National Atmospheric Emissions Inventory's Projections of Emissions and Removals from the LULUCF Sector to 2050/2100 report (PDF, 5.1MB)

• UK local authority and regional greenhouse gas emissions statistics and Energy and emissions projections from DESNZ

• projected non-traded price of carbon schedule in data table 3 of DESNZ's Green Book supplementary guidance: valuation of energy use and greenhouse gas emissions for appraisal for annual value calculations

Noise regulating data sources:

• data from the Scoping UK Urban Natural Capital Account – Extending noise regulation estimates report from Defra

Urban heat regulating data sources:

• temperature data in the HadUK-Grid Gridded Climate Observations on a 12km grid over the UK dataset from the Centre for Environmental Data Analysis and the Met Office

• Regional gross value added (balanced) by industry: city and enterprise regions dataset from the ONS

Recreation and tourism (expenditure) and recreation (health benefits) data sources: 

• recreation data for England from Natural England's Monitor of Engagement with the Natural Environment (MENE) survey and the People and Nature Survey (PaNS)

• recreation data for Wales from NRW's Welsh Outdoor Recreation Survey (WORS), the National Survey for Wales (NSW), and the People and nature survey Wales (PaNSW) from NRW and Natural England

• recreation data for Scotland from NatureScot's Scottish Recreation Survey (ScRS) and Scotland's People and Nature Survey (SPANS)

• recreation data for Northern Ireland from Outscape's People in the Outdoors Monitor for Northern Ireland (POMNI)

• projected population growth data from our Principle projection – UK summary dataset; used to calculate the asset value

• data from the ONS's Living Cost and Food survey (LCF); used to join different surveys together without a step change

• the Great Britain Day Visits Survey (GBDVS) and the Great Britain Tourism Survey (GBTS) from Visit Britain to generate nature-based tourism

• the International Passenger Survey (IPS) from the ONS from Visit Britain

• Northern Ireland annual tourism statistics from the Northern Ireland Statistics and Research Agency (NISRA)

• the quality-adjusted life-year (QALY) in the Methods for the estimation of the National Institute for Health and Care Excellence cost-effectiveness threshold paper by Karl Claxton and others; used to generate a monetary estimate for the health benefits service

Recreation and aesthetic (house prices) data sources: 

• data on property sales from HM Land Registry

• data on imputed rentals for housing in the Consumer trends time series from the ONS 

• House Attributes data from the Valuation Office Agency

• Open greenspace data from the Ordnance Survey

How we process the data and produce the statistics

We process our data for each ecosystem service in a consistent way.

Each ecosystem service and habitat extent are produced using a Python script that links data sources to produce physical flows and monetary estimates.

We carry out quality assurance checks at every stage of the process. These checks are described in the How we quality assure the statistics subsection of Section 3: Quality of these statistics.

Strengths

• Our natural capital accounts follow the United Nations (UN) System of Environmental-Economic Accounting Ecosystem Accounting (SEEA EA) guidance where possible; more information on the principles underpinning the accounts is in our Principles of UK natural capital accounting: 2023 methodology.

• Our accounts are an extension (or "satellite") to the national accounts, which are produced within the UN System of National Accounts (SNA) framework.

• These are currently the only UK statistics with coverage of the 16 ecosystem services for the entire UK and each nation. 

• We use more than 70 data sources from a wide range of providers; over half of our data sources are accredited official statistics, and the rest are in development, ad hoc, or have not gone through the accreditation process.

Limitations

• It is impossible to fully calculate the value of the natural environment in economic terms, as we are limited to the data and methods that are currently available on the appropriate physical and monetary valuations of natural capital services; our accounts do not provide a complete valuation, and they should be interpreted as a partial or minimum value.

• As we improve our methods and data sources, we revise our methodology, so our latest accounts should not be compared with previous editions; our aim is to continually reduce the revisions needed each year.

• It is not always straightforward to interpret a higher or lower value in natural capital; for example, if society produces less pollution across the time series, trees remove lower quantities of pollutants, which decreases the value of the air pollution regulating ecosystem service and results in a lower estimate of natural capital, though a reduction in pollution could be considered a benefit even if it results in a lower natural capital value.

• The accounts have a two-year lag after the reference year, because of data availability; some ecosystem services have a smaller one-year lag, because of timelier data sources.

• Some ecosystem services contain volatile annual values, especially for services where the prices in the market can and do rapidly change; in particular, prices in the oil and gas market can cause fluctuations in the annual value of oil and gas, while the physical flow and asset values for oil and gas are relatively stable.

How we quality assure the statistics

We perform quality assurance at each stage of the process. We quality assure the data that we input from the data source, analyse changes and revisions in the data that we are aware of, and query any unexpected changes. Once the input data are checked and the code is run, we also quality assure our outputs to ensure that the statistics look appropriate, compared with previous years and recent economic and environmental trends. Finally, after producing our detailed and summary data tables, these are also carefully quality assured, along with our bulletin.

Once the bulletin and data tables are completed, they are circulated internally for feedback. Environmental and national accounts experts also peer review our data tables and new methods, allowing us to gather feedback and use their knowledge and expertise. We also carry out a peer review of our data with important subject matter experts within government. Feedback received is then considered in our final outputs.

Official statistics in development

Our natural capital accounts estimates are currently labelled as "official statistics in development".

Official statistics in development means that:

• the statistics are still subject to testing for quality, volatility, and their ability to meet user needs

• new methods are being tested and are still subject to modification or further evaluation

• there is partial coverage (for example, of subgroups, regions, or industries) at that stage of the development

• there may be potential modification about their usefulness and credibility, following user feedback

Official statistics in development may have a greater degree of uncertainty than accredited official statistics. For further information, see our Guide to official statistics in development.

We frequently review the methods and data sources for our natural capital accounts to ensure the accounts make use of the most appropriate data sources available and that our methods are still suitable. For example, method changes or more granular or timely source data could result in improved estimates. This means that developments in the natural capital accounts can result in changes to the overall estimates. These developments are completed in consultation with the data experts and stakeholders to ensure the new methods are as robust as possible.

We highlight the effects of the developments, where possible, within our bulletins.

Recent changes to our methods

This section details recent changes made in our UK natural capital account: 2024 bulletin.

Change in asset value calculation

The UN System of Environmental-Economic Accounting (SEEA) guidance states that asset values should begin from the year after the current year, which is expressed as "year t plus 1". We have changed our methods to only include future years.

Five-year rolling average for timber and fish

We used this method for the asset valuation instead of using the stumpage price (timber) and annual value (fish) of a single year. This brings the methodology in line with other services.

New conversion factors for coal provisioning

We have started using a dynamic-conversion factor instead of a fixed-conversion factor. This is effectively an annual weighted average of the conversion factors of various types of coal produced that year, such as coke. We have added a new conversion data file and applied it to calculate the physical flows.

Changes to estimation of future sulphur dioxide projections

We used previous modelling of pollution concentration from the UK Centre for Ecology and Hydrology (UKCEH) for 2015 and 2030 in our UK natural capital accounts: 2023 bulletin. Our method uses the ratio between the pollutant concentrations between these years. The UKCEH provided new 2015 values for the 2024 accounts by rerunning the European Monitoring and Evaluation Programme (EMEP) and using the ratio to generate new 2030 estimates. We then linearly interpolate the government pollution concentration data for the latest year until it reaches the 2030 estimate.

The latest government concentration data for sulphur dioxide (SO2) dipped below the 2030 estimated value, so applying the method made SO2 increase slightly between 2021 and 2030. We rolled forward the latest SO2 value until 2030, after discussion with UKCEH.

Changes to habitat categories for greenhouse gas regulating

The Department for Energy Security and Net Zero (DESNZ) stated in their 2024 publication that the Territorial Emissions Statistics (TES) sectors will replace the National Communication (NC) sectors in all their publications. This started with their Final UK greenhouse gas emissions national statistics: 1990 to 2022 release. We have updated our habitat categories to match the TES sectors published by DESNZ.

Changes to the recreation and aesthetics (house prices) time series

This year we have included new data from HM Land Registry, allowing us to produce more complete estimates for each property up to 2022. We have also included more up to date Valuation Office Agency (VOA) data, which previously ran to 2017.

Inclusion of data from the People and Nature Survey for Wales for the first time

Our tourism and recreation (expenditure) and recreation (health benefits) estimates included data covering 2021 to 2022 from the People and Nature Survey for Wales. This can replace data that has previously been imputed using the data for England.

Comparability of these statistics over time

We use a consistent method and approach across the time series for each ecosystem service included in our UK natural capital accounts bulletins. This allows users to compare estimates over time and between geographic boundaries for most ecosystem services within the same set of natural capital annual accounts.

Each ecosystem service is available from 2016 onwards. However, some ecosystem services can be produced from 1998 onwards because of data availability. The start date for most ecosystem services falls somewhere between 1998 and 2016. Users should avoid focusing on the total value of natural capital ecosystem services before 2016.

Each of our ecosystem services is produced using a unique method that is applied across all estimated years. However, some ecosystem services use data sources that change or are only available in certain years. For example, in the recreation and tourism (expenditure) ecosystem service, the source for Scotland recreation data – Scotland's People and Nature Survey – is only available up until 2020. As a result, estimates for Scotland after 2020 are modelled using data from the equivalent England survey. Users should be aware that some year-on-year changes could be because of modelling changes, rather than real trends from the source data.

Recreation data for England are taken annually from Natural England's Monitor of Engagement with the Natural Environment (MENE) survey between 2009/10 and 2018/19, and the People and Nature Survey (PaNS) from 2020 onwards. Changes to survey design and mode means that MENE and PaNS are not directly comparable across all variables. For further details on each ecosystem service, please see our UK natural capital accounts methodology guide: 2024.

Comparability with other statistics producers

These accounts have been compiled in line with the guidelines in the United Nations (UN) System of Environmental-Economic Accounting Central Framework (SEEA-CF) and the UN SEEA Ecosystem Accounting (SEEA-EA). These relate to the wider System of National Accounts framework. The natural capital accounts statistics are delivered and published as part of our UK National Accounts: The Blue Book and our UK inclusive wealth and income accounts article.

The Scottish Government publishes their Summary of Scottish Data from UK Natural Capital Accounts report, which highlights and uses the Scottish data from our natural capital accounts.

The Department for Environment, Food and Rural Affairs (Defra) builds on the data produced in the natural capital accounts in their Enabling a Natural Capital Approach guidance. This provides guidance to policy and decision makers to consider the value of the natural environment to people and the economy. Defra also uses data from our natural capital accounts to inform their annual Nature at work for people in the economy report, which offers further context for and interpretation of our statistics and draws out 10 broader policy-relevant lessons.

Differences between measurement approaches

We have also published our interpretation of the UN guidance used to produce our natural capital accounts in our Principles of UK natural capital accounting methodology. This section outlines some differences in our approach, compared with the SEEA-EA.

Our natural capital accounts include abiotic resources, which is a slightly wider definition than the SEEA-EA because abiotic resources are included in the SEEA-CF. This is because including abiotic resources in the ecosystem accounts provides a more comprehensive account of the UK's natural capital.

Our accounts also differ from SEEA guidance on the habitat types included. The SEEA-EA guidance suggests including habitat types levels one to three, in the International Union for Conservation of Nature (IUCN) Global Ecosystem Typology 2.0 (GET). The best available UK-wide land use data are land cover maps from the UK Centre for Ecology and Hydrology (UKCEH). These can be converted into the eight broad habitats that we use. These eight broad habitats are not directly aligned with the IUCN GET.

The SEEA-EA suggests measuring carbon sequestration using two separate services: sequestration and storage. Our natural capital accounts treat sequestration as one service (greenhouse gas regulating).

When the net flux of emissions leads to more emissions being released than are removed, the SEEA-EA suggests the level of service supplied by the ecosystem is zero. When this occurs, our natural capital accounts publish negative figures.

Provide feedback

You can provide feedback on the methods used to produce these statistics and their quality by emailing natural.capital.team@ons.gov.uk.

Provisioning services

Provisioning services refer to tangible goods that people can harvest, extract, or derive from the environment, such as food, water, energy, and materials.

Regulating services

Regulating services help to maintain the quality of the environment we rely on.

Cultural services

Cultural services are the non-material benefits we get from interacting with ecosystems through recreation and tourism, and their associated health benefits.

Agricultural biomass provisioning

Agricultural biomass provisioning estimates the value of crops, fodder, and grazed biomass provided to support agricultural production.  

Coal provisioning

Coal provisioning estimates the value of the production of coal. 

Fish provisioning

Fish provisioning estimates the value of marine fish taken from mainland UK waters. 

Minerals and metals provisioning

Minerals and metals provisioning estimates the value of the extraction of minerals and metals to support production, largely consisting of extraction aggregates.

Oil and gas provisioning 

Oil and gas provisioning estimates the value of production of crude oil and gas. 

Renewable electricity provisioning

Renewable electricity provisioning estimates the value of electricity generated from renewable sources like wind, hydroelectric, solar, and wave and tidal. 

Timber and woodfuel provisioning

Timber and woodfuel provisioning estimates the value of wood production (also referred to as removals), which is the harvesting of roundwood (trunks and branches) from coniferous (softwood) and broadleaved (hardwood) trees. 

Water provisioning

Water provisioning estimates the value of public water supply. 

Air pollution regulating

Air pollution regulating estimates the value of the removal of air pollution by habitats in the UK.  

Greenhouse gas regulating

Greenhouse gas regulating estimates the value of the removal of greenhouse gases, in carbon dioxide equivalent (CO2e), from the atmosphere by habitats in the UK. 

Noise regulating

Noise regulating estimates the value of vegetation that acts as a buffer against noise pollution, such as from road traffic. 

Urban heat regulating

Urban heat regulating estimates the value of green (for example, parks) and blue (for example, lakes) spaces that can cool urban environments on hot days.  

Recreation and tourism (expenditure)

Recreation and tourism (expenditure) estimates the amount spent to enable visits to the natural environment, such as transport, car parking, and admission costs. 

Recreation (health benefits)

Recreation (health benefits) estimates the number of people gaining health benefits from regular recreation, and the monetary value associated with this. 

Recreation and aesthetic (house prices)

Recreation and aesthetic values for house prices are the additional expenditure on houses that are near to or contain green (land) and blue (water) spaces, enabling people to make free trips to the natural environment, as well as the value added to a property by a view of a green or blue space.