To help address climate change, a UK-wide target of reaching net zero greenhouse gas emissions by 2050 has been adopted. This means reducing carbon dioxide (CO2) emissions, with any remaining emissions offset by measures that remove greenhouse gases from the atmosphere, including increasing numbers of trees.
The UK Government has set a target for at least 30,000 hectares of trees a year to be planted by the end of this Parliament (May 2024), while the devolved administrations for Wales, Scotland and Northern Ireland also have plans for new woodland. The UK annual tree planting target is equivalent to an area twice the size of Cardiff or almost the size of the borough of Milton Keynes.
The Department for Business, Energy and Industrial Strategy (BEIS) produces annual CO2 emissions estimates for the UK nations, nine English regions and individual local authority areas. CO2 accounted for 80% of greenhouse gas emissions in the UK in 2019, with the rest including methane (12%), nitrous oxide (5%) and fluorinated gases (3%).
Total UK CO2 emissions fell by 36% between 2005 and 2019, but the picture varies depending on where you live.
In England, overall CO2 emissions reduced by 36% between 2005 and 2019, compared with 35% in Scotland, 29% in Wales and 23% in Northern Ireland.
Across the English regions level, between 2005 and 2019 CO2 emissions fell the most in percentage terms in the North East (56%) and the least in the East of England (30%).
Various changes have contributed to the national fall in CO2 emissions. In the energy sector and in industry, such as manufacturing, there has been a decrease in the use of coal for electricity generation and an increase in the use of renewable sources.
Annual CO2 emissions, kilotonnes per kilometre squared, 2005 to 2019, UK local authority districts
- The CO2 estimates used include those emitted within a local authority area, including from large industrial sites, railways, land use and motorways that pass through but are not within the control of local authorities. We have used emissions estimates per km2 to show change over time as these are not affected by population change the way a per capita rate would be.
Out of 379 local authority districts in the UK, parts of Greater London had the highest CO2 emissions by area in 2019.
The City of London, historically the UK capital’s financial district, had 203 kilotonnes (kt) CO2 per kilometre squared (km2), down by 61% since 2005. However, it is also the smallest local authority area at just 3 km2.
Area emissions in Westminster were 77 kt CO2 per km2 in 2019, down 50% from 155 kt CO2 per km2 in 2005, with the next 11 areas with the highest CO2 emissions per km2 all London boroughs: Kensington and Chelsea, Tower Hamlets, Camden, Islington, Hammersmith and Fulham, Lambeth, Hackney, Southwark, Newham, Wandsworth and Haringey.
Slough had the highest CO2 emissions by area outside London in 2019, at 21 kt CO2 per km2, down by 18% since 2005.
Although Northumberland had the highest percentage fall in CO2 emissions per km2 since 2005 (down by 82%), it started from a comparatively low base of less than 1 kt CO2 per km2.
Redcar and Cleveland, an area known for large industrial installations, some of which closed recently, has seen its CO2 emissions by area fall 77% from 42 kt CO2 per km2 in 2005 to 10 kt CO2 per km2 in 2019.
Emissions decreased the least in percentage terms in Neath Port Talbot, down by 9% from 17 kt CO2 per km2 in 2005 to 16 kt CO2 per km2 in 2019. The area is also known for heavy industry.
While local data only cover up to 2019, the Office for National Statistics (ONS) has published UK provisional emissions for 2020 with breakdowns for broad industrial sectors and households.
These suggest that household emissions fell by 10% on the previous year, with the largest reduction in emissions in the transport and storage sector falling by 40%.
How land is used will play a role in removing, or “sequestering”, some of the emissions that are produced. Trees absorb CO2 through photosynthesis. In 2017, woodland in the UK is estimated to have removed 18 million tonnes of CO2, which is equivalent to 4% of the total UK greenhouse gas emissions that year, not including shipping or aviation.
The area of tree-covered woodland in the UK has increased by 11% between 1998 and 2021.
In the year ending March 2021, woodland covered about 3.2 million hectares (13%) of the UK’s land area and, by proportion of area, accounted for:
- 10% of England
- 15% of Wales
- 19% of Scotland
- 9% of Northern Ireland
This compares with an average estimated woodland coverage of 31% worldwide, 32% in France, 33% in Germany and 11% in the Republic of Ireland in 2020.
Woodland as a percentage of area, local authority districts, UK, 2019
- Woodland cover for Great Britain is based on areas of trees of at least 0.5 hectares, wider than 20 metres, with a minimum of 20% canopy cover, or the potential to achieve it. In Northern Ireland, woodland is classed as an area of trees of 0.1 hectares or more. See Measuring the data for more information
- In 2017, there were around 742,000 hectares of trees outside woodland in Great Britain that are not shown in the map, including 390,000 hectares of small woods between 0.1 and 0.5 hectares in size.
Our analysis of the latest local estimates for 2019 showed that the area with the highest percentage of woodland cover (excluding inland water) in the UK was Neath Port Talbot in South Wales, where 39% of land was woodland. It had the 23rd highest CO2 emissions by area (per 16 kt CO2 per km2) out of UK local authorities in 2019.
In England, Waverley in Surrey had the highest proportion of its area covered by woodland, with almost 34% in 2019. The highest in Scotland was Moray, with around 30% of its area covered by woodland, while in Northern Ireland the highest woodland cover was 13% of Fermanagh and Omagh.
The areas with the lowest percentage of land covered by woodland were Shetland (0.04%) and the Orkney Islands (0.2%).
The Committee on Climate Change, which advises the government on emissions targets, recommends that woodland should be increased to at least 17% of land area by 2050 to raise the amount of greenhouse gases that are removed from the air and stored by trees.
The Forestry Commission has found strong public support for tree-planting, with 83% of those surveyed in the UK in early 2021 who had visited woodland in the previous few years agreeing with the statement that “a lot more trees should be planted” in response to the threat of climate change.
Some of the areas with low percentages of woodland include places with large amounts of wetland, while about 12% of the UK land area is peatland.
Parts of Lincolnshire and Cambridgeshire, along with areas of Norfolk and Suffolk, are known as The Fens. South Holland in Lincolnshire has 0.4% woodland. Fenland in Cambridgeshire has 0.5% as does Boston in Lincolnshire.
According to Natural England (PDF, 3.5 MB), deep fen peats are found in the Fens of Cambridgeshire and Lincolnshire, around the Broads and Fens of East Anglia, the Somerset Levels and the Lancashire Mosslands. While trees remove carbon dioxide from the air, peat bogs also store large amounts of carbon. However, when peat bogs are in a poor condition they release greenhouse gases.
Planting trees on deep peat leads to the drying out of the soils and release of greenhouse gases, so the UK Forestry Standard (UKFS) says planting trees should be avoided on peat deeper than 50cm.
The net benefits, in terms of climate change emissions alone, of restoring 55% of peatlands to near natural condition were estimated in 2019 to have a value of approximately £45 billion to £51 billion over the next 100 years.
The Committee on Climate Change, which recommended the 30,000 hectare a year target for new woodland, as adopted by the UK government, says this is equivalent to between 90 and 120 million trees, depending on planting density.
To put this target into perspective, 30,000 hectares would be similar to planting enough trees every year to cover Cardiff (14,000 hectares) or Belfast (14,000 hectares) more than twice, or more than cover the whole of the City of Edinburgh (26,000 hectares), or almost cover the Milton Keynes local authority area (31,000 hectares).
The most recent year when new woodland planting in the UK was 30,000 hectares or more was April 1988 to March 1989.
On the latest figures, for the year ending 31 March 2021, there were 13,290 hectares of new woodland planted in the UK. This compares with 13,660 hectares in the year ending 31 March 2020.
Hectares, thousands, of new woodland planted in the UK, years ending 31 March, 1976 to 2021
The type of tree being planted is also important. The Committee on Climate Change assumes a 60:40 split of broadleaf to conifer trees.
Conifer species, such as the Sitka spruce, which is widely planted in forests, tend to grow faster and therefore absorb carbon faster, but broadleaf species, such as oak, store more carbon in the long term.
Conifers account for approximately half (51%) of the UK woodland area in 2021, with just over half (56%) of these conifers privately owned. In contrast, the majority (92%) of broadleaved woodland is privately owned.
Measuring the data
Local authority area CO2 estimates are quoted on an ‘end-user’ basis. This means that emissions from energy supply, such as those from power stations and refineries, are allocated to areas based on their energy use rather than the location where the emission occurs. Other emissions are allocated based on the location of the emission. The CO2 estimates used include those emitted within a local authority area, including from large industrial sites, railways, land use and motorways that pass through but are not within the control of local authorities. More information can be found in the BEIS statistical release.
The National Forest Inventory (NFI) woodland map for 2019 was used, to work out the percentage of local authority areas comprised of woodland. Released in June 2021, this provides the most up-to-date local dataset on woodland in Great Britain. Only woodland that covers more than 0.5 hectares and is wider than 20 metres, with a minimum of 20% canopy cover, or the potential to achieve it, is included; trees in private gardens and parks are not included. In 2017, there were around 742,000 hectares of trees outside woodland in Great Britain that are not shown in the map, including 390,000 hectares of small woods between 0.1 and 0.5 hectares in size. Northern Ireland data for 2019 came from the Northern Ireland Woodland Register. For these data, woodland is an area of trees, excluding agroforestry, orchards and other non-forestry uses, of at least 0.1 hectare and an average width of greater than 20 metres. We have used the 2020 Standard Area Measurements, excluding areas of inland water.