With the world facing the twin crises of climate change and biodiversity loss, forests have come into focus as one of the key solutions for tackling both. Pledges to halt and reverse deforestation have formed part of international agreements such as the UNFCCC, and many governments have committed to increasing tree cover. In the UK forests and woodlands have been particularly high up the agenda as we have one of the lowest areas of tree cover and one of the highest rates of biodiversity loss in the world.
Although tree planting initiatives have proliferated across the globe, very few of these projects are incorporating timber production into their plans. At first glance productive forestry seems entirely incompatible with reducing excess carbon dioxide and meeting net-zero goals due to regular felling. However, with global timber demand set to increase dramatically as the construction industry looks for more sustainable alternative materials, we are heading towards a worldwide timber shortage, leading to escalating prices and a higher risk of unregulated deforestation. Is there a way in which forests can store carbon dioxide and increase biodiversity, but also produce timber sustainably, resolving these apparent conflicting interests?
The global demand for timber is predicted to increase dramatically over the next 20-25 years, with estimates ranging from a doubling to a quadrupling of requirements according to the World Bank. This increase will significantly exceed the current global supply and will be driven by the need to use construction materials that have a lower carbon footprint in order to reduce excess emissions and meet net-zero goals. Changes in the type of housing being built also affects demand, with increasing areas of lower density housing requiring more timber than apartment blocks. The buildings and construction industry is responsible for 37% of global emissions and the pressure is on to decarbonise, with timber providing an excellent renewable alternative that stores carbon long term and is available at scale. Timber is described as the ultimate renewable resource, and when forests are managed sustainably, it is often touted as being carbon neutral, although more recent research queries how long it takes to balance the carbon lost in the felling and production process.
Against a background of increasing geopolitical instability, the security of non-domestic timber supplies could be jeopardised in the years to come. Russia in particular is the largest supplier of timber and wood products globally, but with sanctions on exports, the supply of their timber will be affected. Scarcity will inevitably affect prices, as was demonstrated in 2021 when demand for timber during the pandemic outstripped supply and prices jumped by more than a fifth. This has downstream effects of increasing the cost of projects and delaying their completion. This could jeopardise government house building targets if not addressed.
If rising global demand for timber is associated with an increase in the felling of natural forests, it could lead to a dramatic upsurge in carbon emissions. The end result could be that the timber industry contributes 10% of carbon emissions by 2050, three times the proportion of the aviation industry. It is predicted that a 90% increase in demand for wood products between 2010 and 2050 will lead to an area the size of the continental US being harvested. At a time when we should be upscaling the removal of carbon dioxide from the atmosphere, this represents a catastrophic increase in emissions.
The UK is currently the third largest net importer of timber in the world, importing over 80% of the wood that we use, the vast majority of which is softwood from conifers. For a country that has an ideal climate for growing trees, this is a surprising and alarming figure, causing our shipping and transport footprint to escalate. Although tree cover across the UK has increased from 12% to 13.4%, most of the new planting has been broadleaved deciduous trees (particularly in England), which are currently less favoured by the construction industry for timber. In spite of concerted efforts by the government to boost tree planting rates and achieve 16.5% tree cover in England by 2050, there was a 7% decrease in new planting in 2022 / 2023 and a 19% decrease in restocking. The switch away from conifer planting in conjunction with these declining tree planting rates mean that we are unprepared for any increase in homegrown timber requirements,
The uses of timber from UK forests is split quite evenly between sawnwood, wood-based panels, and paper, but demand for construction materials is increasing as the construction industry switches to timber as a more sustainable building material. The UK has planted almost no new large forests aimed at timber production for the past 30 years though, and with planting rates of conifers falling, we are facing a significant gap between demand and our ability to supply from UK forests. Without urgent action to increase our productive forestry reserve, imports will be driven even higher with their associated larger transport footprint. This will lead to increased pressure on forests abroad which are less well regulated and could drive illegal logging.
Over the last three decades, conifer plantations in the UK have been removed and restructured to favour more native broadleaved tree species, resulting in a significant reduction in the stocked area. In simple terms, we have not been replanting anywhere near enough conifers to support existing demand, let alone increased demand. In parallel with the low levels of new conifer planting, demand for timber has been increasing and the net result is a reduction in productive conifer forest. Forestry Commission data from 1997 highlighted that the previous 24 years had seen a loss of 40,000 hectares of coniferous forest in England, trees which have not been replanted since. The most recent 25 year softwood availability forecast from Forest Research predicts a 50 million m3 reduction in conifer volume in the next 20 years, driving the gap between demand and supply even further.
The need to highlight these issues and push for progress in planting more productive woodland led to the creation of the National Wood Strategy for England in late 2023. The England Forest and Wood-Based Industry Leadership Group (ILG) compiled the strategy in conjunction with the Confederation of Forest Industries (CONFOR) and a wide variety of forestry and environmental organisations. This document aims to set out how to achieve a sustainable timber industry which allows productive forestry to contribute to net-zero goals and increasing biodiversity.
A recent study in Nature calculated the impact that increased demand for timber could have on global emissions and highlighted that the way to avoid this is by increasing the productivity and area of timber plantations. By increasing the yields of existing plantations by 50% over 40 years, global emissions would be reduced by 600 million tons per year during this period according to their estimates. The harvesting technique itself could be improved in tropical forests so that trees adjacent to those being felled are protected, increasing savings by another 200 million tons. The researchers also highlighted that alternatives should be found to burning woody biomass, which is increasing demand for wood in the U.S., British Columbia, Eastern Europe, Scandinavia, and Southeast Asia. The demand for roundwood timber is currently equivalent to the amount of wood required for fuel, but if woodfuel use could be reduced by 40% instead of increasing by 20%, global emissions would decline by another 500 million tons.
Different tree species have varying growth rates and hence differ in their value for carbon sequestration. Slow growing broadleaved woodland, which is what we tend to plant for conservation reasons in England, develops into a long-term living store of carbon. By contrast conifers grow much quicker and provide faster carbon absorption. Indeed modelling of the potential of different categories of forest to sequester carbon in the fight against climate change identified that productive forestry plantations in the UK have more potential to reduce excess carbon in the atmosphere by 2100, even when those stands are harvested and replanted. The amount of carbon stored by UK forests is increasing, with most of it being stored in the soil, but tree planting rates in the UK are still far below what is required to achieve the government 16.5% tree cover figure for England. The National Wood Strategy for England also argues that the government tree cover figure is too low and should be increased to 17.5%. By improving harvesting techniques and increasing productivity per hectare, commercial timber production has the potential to make a significant contribution in the fight against climate change.
Productive forest plantations also contribute to other ecosystem services although water provisioning, biodiversity, and particularly soil erosion prevention is higher in native forests when considered globally. In the UK there has been a drive to prioritise native woodland planting, which is partly why conifer planting rates have been low. There is a misconception that conifer plantations are devoid of ecological value and do not contribute to biodiversity, but evidence shows that particular animal species have adapted to our non-native conifer plantations. In particular bird species such as goldcrests, siskins, coal tits, crossbills, and crested tits have become specialists of non-native conifer plantations, and red squirrels and pine martens thrive in plantations. The UK Forestry Standard also stipulates that new forest plantations must include a minimum of 5% native broadleaved trees or shrubs, aiming to increase diversity.
The National Wood Strategy sets out a series of goals to address the national timber shortage and ensure that commercial forestry delivers for climate and biodiversity.
1. Stabilise and then increase the timber resource in England
2. Exceed the statutory government target for tree and woodland cover
3. Increase the use and lifespan of English wood
4. Create a predictable and consistent investment environment
5. Develop a consistent and positive message on productive woodlands
6. Develop a skilled workforce
Within the goals are a series of targets that aim to drive up timber production, invest in the forestry industry workforce, and maximise the ecosystem services delivered by commercial forestry. These include ensuring that 40% of annual new planting in England is stocked coniferous species, aiming for 104,000 hectares of extra stocked productive conifer forest in England by 2050. The strategy is also targeting 52,000 hectares of new productive broadleaved woodland by 2050 and wants to promote a positive perception of productive forestry in England. The strategy sets out methods by which this can be achieved including attractive offers for farmers that avoid penalising them for converting to woodland and streamlining the woodland creation application process to improve efficiency.
With improved collaboration and a defined strategy in place, the future of forestry in the UK could be bright, increasing timber production and investing in ecosystem services. Timber production and environmental benefits do not need to be mutually exclusive, and the forestry industry can work for both people and the planet.