D1b. Removal of greenhouse gases by UK forests
Type: Benefit indicator
This indicator was updated in 2023.
Introduction
Forests are a large store of carbon and also act as an active carbon ‘sink’, removing carbon dioxide (CO2), a greenhouse gas (GHG), from the atmosphere and storing it as carbon in living biomass, leaf litter and forest soil. This sequestration of CO2 is an essential ecosystem service. This indicator shows the cumulative net removal of greenhouse gases from the atmosphere by UK forests since 1990. It is split between type of woodland (conifer and broadleaf). Showing greenhouse gas removals by type of woodland is interesting from a biodiversity perspective as it allows a clearer presentation of the contribution made to greenhouse gas removals by broadleaf woodland, most of which constitutes a UK priority habitat.
Key results
It is estimated that from 1990 to 2021, forests in the UK have (cumulatively) removed the equivalent of 542 million tonnes of carbon dioxide (MtCO2e) from the atmosphere (Figure D1bi). In 2021, UK forests are estimated to have removed 18 MtCO2e (Figure D1bii).
The proportion of greenhouse gases removed from the atmosphere by broadleaf woodland has fluctuated through the time series, but was greater in 2021 than when the time series began, accounting for 52% (9.1 MtCO2e) of the estimated annual removals in 2021 compared to 43% (5.8 MtCO2e) of removals in 1990 (Figure D1bii).
Figure D1bi. Cumulative net removals of greenhouse gases by UK forests, 1990 to 2021
Notes about Figure D1bi:
- Estimated cumulative net removals of greenhouse gases (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)) from the atmosphere by forests in the UK, expressed as million tonnes of CO2 equivalent (MtCO2e).
- Revised in 2015 to reflect improved modelling of greenhouse gas emissions and removals.
- Revised in 2019, 2020, 2021 and 2023 due to further improvements in the CARBINE model and forest planting and harvesting statistics in all four years and implementation of peatlands research in 2021 (see Background section for more details).
- These results are therefore not directly comparable with those in previous publications.
Source: Department of Business, Energy & Industrial Strategy – Land Use, Land Use Change and Forestry (LULUCF) greenhouse gas inventory.
Assessment of change in cumulative net removal of greenhouse gases
| Long term | Short term | Latest year | |
| Higher-level or targeted schemes |
Improving 1990–2021 |
Improving 2016–2021 |
Increased (2021) |
Notes for Assessment of Change table:
Long- and short-term assessments are based on a 3% rule of thumb. The base years for these assessments use a three-year average. See Assessing Indicators.
Indicator description
The data presented here are from the UK’s Land Use, Land Use Change and Forestry (LULUCF) greenhouse gas inventory, which provides estimates of the annual rate of emissions and removals of greenhouse gases (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)) from the atmosphere by forests in the UK between 1990 and 2021 (Figures D1bi and D1bii). LULUCF emissions and removals are given in terms of carbon dioxide equivalent (CO2e). The CO2e of a mixture of greenhouse gases is the quantity of CO2 that would have the same global warming potential.
Relevance
The benefits that humans receive from the environment have become more widely recognised. The Millennium Ecosystem Assessment and the more recent UK National Ecosystem Assessment both highlighted that ecosystems and the services they deliver underpin our very existence. We depend on them to produce our food and timber, regulate water supplies and climate, and breakdown waste products. We also value them in less obvious ways: contact with nature gives pleasure, provides recreation and is known to have a positive impact on long-term health and happiness. Measuring the status of ecosystem services is therefore a critical aim of the indicator set. Greenhouse gas removal is a regulating service that contributes to reducing the scale and future impacts of climate change (climate change mitigation).
Background
National Inventories of human-induced sources and sinks of greenhouse gases are submitted by Parties, including the UK, to the United Nations Framework Convention on Climate Change (UNFCCC) every year. This system was set up to meet the reporting obligations of the Convention and is used to report on progress in meeting Kyoto Protocol commitments. The Kyoto Protocol, which entered into force in 2005, obliges industrialised countries that have ratified the accord to reduce their emissions of six greenhouse gases, the major contributors being CO2, CH4 and N2O. The LULUCF greenhouse gas inventory covers emissions and removals of these three greenhouse gases resulting from direct human-induced land use, land-use change and forestry activities. The LULUCF estimates are compiled for the Department for Energy Security & Net Zero by the UK Centre for Ecology & Hydrology (UK CEH) and Forest Research (FR).
The forestry figures in the 1990 to 2021 LULUCF inventory have been revised and therefore the figures presented here are not directly comparable to those in previous publications. Changes are due to improvements made to the FR CARBINE model and a full explanation of the (most recent) changes can be found on page 400 of the National Inventory Report. Briefly, the reported overall net GHG sink in forest land (category 4A, see report) has reduced by between -0.2 and -0.5 MtCO2e (-1 to -3%) across the time-series compared to the previous inventory.
The changes are/relate to:
- Updated activity data.
- Updated EF for POC emissions from organic soils.
- Updated forest area on organic soils.
- Minor changes to average biomass densities used for wildfire emission calculations.
- Updated N2O and CH4 EFs from organic soils.
The effect of these model changes is a decrease in both the broadleaf and conifer forest GHG sinks for all years between 1990 and 2021. More specifically, decreases to the conifer sink were of a greater magnitude than those to the broadleaf sink and decreases to both GHG sinks are more pronounced in the later years of the time-series.
Figure D1bii shows the annual breakdown of the cumulative removals shown in Figure D1bi. Although the indicator (for cumulative net removals) is assessed as improving in both the long term and short term since cumulative greenhouse gas removals have continued to increase, it should be noted that annual rates of removal have remained relatively static in recent years. It is also worth noting that the proportion of removals attributed to broadleaf woodland has fluctuated through the time series, but was greater in 2021 than when the time series began.
Showing greenhouse gas removals by type of woodland is interesting from a biodiversity perspective as it allows a clearer presentation of the contribution made to greenhouse gas removals by broadleaf woodland, most of which constitutes priority habitat.
Figure D1bii. Annual net removals of greenhouse gases by UK forests, 1990 to 2021
Notes about Figure D1bii:
- Estimated annual net removals of greenhouse gases (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)) from the atmosphere by forests in the UK, expressed as million tonnes of CO2 equivalent (MtCO2e).
- Revised in 2015 to reflect improved modelling of greenhouse gas emissions and removals.
- Revised in 2019, 2020, 2021 and 2023 due to further improvements in the CARBINE model and forest planting and harvesting statistics in all four years and implementation of peatlands research in 2021 (see Background section for more details).
- These results are therefore not directly comparable with those in previous publications.
Source: Department of Business, Energy & Industrial Strategy – Land Use, Land Use Change and Forestry (LULUCF) greenhouse gas inventory.
National Forest Inventory
The estimated carbon stock of woodland trees in the UK can be used as a complementary measure of carbon storage. Information on current carbon stocks of forests in the UK were first gathered in 2014 using National Forest Inventory (NFI) data, based on a sample of woodlands equal to or greater than 0.5 hectares in size.
Fieldwork for National Forest Inventory data on carbon stock of all species of tree within forests in the UK is conducted every five years. The latest data is to 31 March 2020. At this point, there was estimated to be a total of 250 Mt of carbon (916 MtCO2e) across all species of tree within forests in the UK (see Figure D1biii). Broadleaved trees, with an estimated carbon stock of 130 Mt (476 MtCO2e), were responsible for a slightly greater proportion of the total UK carbon stock than conifer trees, which were estimated to have a total stock of 120 Mt (440 MtCO2e). This difference reflects the fact that in the UK, the total ‘growing stock volume’ (as opposed to the total area) of broadleaved woodland covered by the NFI is slightly greater than that of conifer woodland.
Figure D1biii. Total carbon stocks in living conifer and broadleaved woodland trees in the UK, 1990 to 2020
Notes about Figure D1biii:
- Estimated total carbon in all living trees within woodlands of England, Scotland, Wales and Northern Ireland (in million tonnes, Mt).
- The time-series is non-linear (indicated by the dashed vertical lines on the x-axis).
Fieldwork for the current NFI began in 2009 and is being conducted on a five-year cycle. The assessment of woodland carbon stocks from this inventory has formed a new baseline for carbon accounting within British forests and woodlands. Estimates of carbon stocks are determined by the total growing stock volume of woodland; a function of:
- Woodland area; and
- Woodland characteristics (e.g. number of trees, tree height and tree diameter) within this area.
Table D1bi shows a comparison of the estimated amount of carbon in living woodland trees in the UK and in each of the four individual countries as at 31 March 2020. England was estimated to have a total of 125 Mt of carbon in living trees (50% of the total for the UK); Scotland, an estimated 96 Mt (38% of the UK total); Wales, an estimated 24 Mt (10% of the UK total); and Northern Ireland, an estimated 5 Mt (2% of the UK total).
Source: Forestry Commission – National Forest Inventory.
Table D1bi. Total carbon stocks in coniferous and broadleaved woodland trees in the UK, by country, as at 31 March 2020 (Mt carbon)
| All conifers | All broadleaves | All species* | |
| England | 29.8 | 95.5 | 125.3 |
| Scotland | 75.0 | 20.9 | 96.0 |
| Wales | 10.7 | 13.0 | 23.7 |
| Northern Ireland | 4.5 | 0.5 | 5.0 |
| United Kingdom | 120.0 | 129.8 | 249.9 |
Notes about Table D1bi:
* Totals may not add due to rounding.
The latest NFI fieldwork cycle began in 2015 and ran until 2020. The NFI assessment of woodland carbon stocks was used in the development of the reporting on LULUCF emissions and removals. However, as there are differences in both the scope and the data sources used for LULUCF (sequestration) and NFI (stock) figures, they are not directly comparable. More information can be found in the Forest Research Report (PDF, 1.29Mb).
Goals and Targets
The UK and England Biodiversity Indicators are currently being assessed alongside the Environment Improvement Plan Targets, and the new Kunming-Montreal Global Biodiversity Framework Targets, when this work has been completed the references to Biodiversity 2020 and the Aichi Global Biodiversity Framework Targets will be updated.
Aichi Targets for which this is a primary indicator
Strategic Goal D. Enhance the benefits to all from biodiversity and ecosystems.
Target 14: By 2020, ecosystems that provide essential services, including services related to water, and contribute to health, livelihoods and well-being, are restored and safeguarded, taking into account the needs of women, indigenous and local communities, and the poor and vulnerable.
Target 15: By 2020, ecosystem resilience and the contribution of biodiversity to carbon stocks has been enhanced, through conservation and restoration, including restoration of at least 15% of degraded ecosystems, thereby contributing to climate change mitigation and adaptation and to combating desertification.
Aichi Targets for which this is a relevant indicator
Strategic Goal B. Reduce the direct pressures on biodiversity and promote sustainable use.
Target 7: By 2020, areas under agriculture, aquaculture and forestry are managed sustainably, ensuring conservation of biodiversity.
Web links for further information
- Carbon in live woodland trees in Britain:
National Forest Inventory Report (PDF, 1.29 Mb) - Understanding the carbon and greenhouse gas balance of forests in Britain (PDF, 7.24 Mb)
- Millennium Ecosystem Assessment Reports
- LULUCF Greenhouse Gas Inventory
- UK National Ecosystem Assessment
Downloads
Download the Datasheet from JNCC's Resource Hub.
Last updated: November 2023
Latest data available:
- Cumulative/annual net removals of greenhouse gases by UK forests – 2021
- Total carbon stocks in living conifer and broadleaved woodland trees in the UK – 2020
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