- ➔ The world will need more renewable materials. The global consumption of all natural resources is expected to more than double from 92 billion tonnes per year in 2017 to 190 billion tonnes in 2060, assuming a continuation of current trends.
- ➔ An increase in forest area and sustainable forest management could support a green recovery and a transition to carbon-neutral economies. In construction, for example, replacing a non-wood material with a wood product would, on average, avoid carbon emissions of 0.9 kg of carbon for every 1 kg of carbon in wood.
- ➔ There is potential to mobilize forest-based industries to scale up innovative green value chains. For example, the non-food biobased industries are estimated to grow by 3.3 percent per year to 2030, when output is projected to be worth USD 5 trillion.
The annual global consumption of all natural resources, such as biomass, fossil fuels, metals and minerals, is projected to more than double from 92 billion tonnes in 2017 to 190 billion in 2060 (Figure 11) as a consequence of population growth and increasing affluence.284 This added demand will strain natural resource systems, including forests.
Figure 11Projected global material extraction, 2015–2060, assuming a continuation of current trends
Seventy-five percent of total material demand today is met by non-renewable resources; the remaining 25 percent is supplied by biomass, which comprises organic materials such as food crops, meat and dairy products and a host of forest and other biomass products. Worldwide, biomass extraction increased from 9 billion tonnes in 1970 to 24 billion tonnes in 2017 and is expected to reach 44 billion tonnes by 2060.285
The agrifood industry accounts for most of the biomass consumption worldwide. The global harvest of major crops, such as cereals, oil and sugar crops, roots, tubers and pulses, amounts to about 27 percent of the global biomass used for food, fodder, fibre and forest products.286 The timber and wood-based industry is another key biomass-consuming sector, with world production of roundwood (at 3.91 billion m3 in 2020) increasing by 12 percent in the last two decades.287
Demand for biomass is expected to rise further to meet growing needs for food, energy, housing and other material uses. Demand for forest-based biomass will be driven mainly by construction (with demand in that sector expected to almost triple by 2030) and packaging (with demand expected to double by 2030).288 Sustainably meeting demand for forest-based biomass will require an increase in resource supply through restoration, reforestation and afforestation on degraded lands and increased resource efficiency. Sustainability also requires efforts to improve manufacturing efficiency and energy flows, promote the cascading use of forest products, change consumption patterns, and facilitate a transition to more circular economies.
When sustainably produced, wood has significant potential to reduce greenhouse-gas emissions from the building and construction sector
Providing housing for a growing and increasingly urbanized population is a major challenge. Globally, an estimated 3 billion people (40 percent of the world population) will need new housing by 2030, which translates into a need for 300 million new dwellings (between 2016 and 2030).289
The construction sector, which was responsible for almost 40 percent of energy- and process-related GHG emissions in 2018,290 will thus pose a major threat to sustainability. Eleven percent of the total emissions of the building and construction sector can be attributed to materials; transitioning to carbon-storing renewable construction materials such as wood, therefore, could be a significant means for mitigating climate change.291,292
Product-level studies that estimate the substitution effect underscore the important role that wood buildings can play in decarbonizing the construction sector. A recent literature review concluded that wood has a median substitution factorh of 0.9 – in other words, every 1 kg of carbon in wood that replaces a non-wood material in a building system could produce an average emission reduction of about 0.9 kg of carbon.293 A study in Finland found that, due mainly to the environmental benefits of wood as a construction material, residents of wooden houses have a 12 percent lower carbon footprint (amounting to 950 kg CO2e per year), on average, than residents of non-wooden houses.294 Wooden buildings also have positive impacts on the physical, mental and emotional health of occupants.295 According to a study in Australian workplaces, biophilic designs that incorporate exposure to wood can reduce sick leave and increase the overall well-being of workers, leading to a 5 percent increase in productivity.296
The development of “mass timber” construction and associated novel wood-frame multistorey construction practices has led to significant growth in demand for engineered wood products, particularly cross-laminated timber. Although the majority of cross-laminated timber projects are in developed countries, wood construction is poised to gain momentum in other parts of the world, too (Box 13).
Box 13 Gabon promotes cross-laminated timber buildings
Gabon created the Gabon Special Economic Zone (GSEZ) in 2010, considered the world’s first certified carbon-neutral industrial zone.297 The zone, which is a joint venture between the Government of Gabon, Olam International and the African Finance Corporation, was developed at a cost of USD 400 million as a platform for establishing wood-processing facilities in Africa. The development of the wood sector, including the sustainable construction of the built environment, is among the governmental priorities identified in Gabon’s “Emergent 2025” national strategy to reduce greenhouse-gas emissions, encourage the sustainable use of forest products and tap into emerging markets.298 The government also launched an initiative to construct Gabon’s first cross-laminated timber building, the Gabon Sovereign Wealth Tower. This project aims to maximize the use of locally sourced wood materials; achieve design excellence for mass-timber-based mixed-use development and zero-carbon construction; anchor the development of mass-timber value chains in sustainable forest management; and enhance the transfer of skills in timber value chains and the construction sector. According to initial calculations, the tower has the potential to remove about 1.5 million kg of carbon dioxide from the atmosphere, a weight equivalent to 36 Boeing 737-800s.299
The increased use of wood in construction can contribute to economic development in the global South. For example, under one scenario, it has been estimated that the production and primary processing of wood to meet expected demand for housing could contribute up to USD 83 billion to Africa’s bioeconomy by 2050 while creating 25 million jobs through the additional forest plantations and processing needed to develop the building materials.300 Unlocking this potential, however, requires investment to strengthen technological and human capacity.
Wood encouragement policies, which, in developed countries, tend to focus on public procurement for buildings and infrastructure, can support and promote the use of wood in built environments (Box 14).301
Box 14 Wood encouragement policies
Wood encouragement policies (WEPs) are policies formulated at the national or subnational level to promote the use of wood as a building material – they are in place in (for example) Australia, Canada, France, Germany, Japan, New Zealand and the United States of America. WEPs are designed to support local forest industries, sustainable economic development and climate-change mitigation objectives. Most, but not all, WEPs target public buildings.
Unfavourable building codes can inhibit the greater use of wood in multistorey buildings. Recent changes to building codes at the international (e.g. the 2021 International Building Code), national (e.g. Australia) and provincial (e.g. British Columbia, Canada) levels have been introduced to enhance the use of wood in the building construction sector.302,303
The World Business Council for Sustainable Development estimates that biomass demand will grow by 8.8 percent per year to 2030 due to the building and construction sector,304 and greater interest in buildings based on mass timber might further increase demand. Sustainably meeting such heightened demand will require greater resource efficiency (among other things), which is increasingly feasible, such as through off-site construction approaches involving digitally precise designs, prefabrication and the remote assembly of building components.
Improvements in material efficiency can help sustainably meet global wood demand
Minimizing any negative environmental implications of the forecast increase in wood demand requires an increase in efficiency and avoidance of wood loss and waste in harvesting and processing. Improvements in material efficiency are underway. An assessment of efficiency improvements in Canada, for example, found that the rate of harvested wood use increased from 61 percent in 1970 to 83 percent in 2016; moreover, residues from solid-wood processing and pulping processes are increasingly used as biomass fuel to substitute fossil fuels.305
Efficiency gains can be amplified through the cascading use of wood raw materials. These can be estimated through “material balances”, which approximate material losses by estimating the difference between the quantity of total material consumed in one processing step and the total material produced in the following processing step.i The path of cascading use and the range of estimated losses provide indications of where and how much efficiency gains might be possible. In the case of sawnwood production, for example, reporting countries indicate that 45–66 percent of the roundwood volume used becomes sawnwood, about one-third becomes chips and slabs, approximately one-tenth becomes sawdust and, in some countries, an additional 2–10 percent becomes shavings (Figure 12).306 What is not used for any of the above products is considered shrinkage loss, which varies considerably between countries due to (for example) differences in species, the portfolio of products produced, available markets, and technologies.
Figure 12Material balance in the sawmilling process for non-coniferous sawnwood
The percentage of material used for low-value products or lost through shrinkage may be much higher in developing countries with only limited use of modern technology across the harvesting and processing stages and with limited access to markets for the full suite of wood products. Adding value across the cascade of products could extend material lifespans, reduce original demand for material, and extend carbon storage times and thus enhance the sustainable use of forest products. Wood residues from the industrial processing of roundwood can be a valuable resource if used as feedstock for other products and if ultimately used for energy generation, substituting for less-sustainable energy sources.
Recycling and re-use, which increase the lifespan of products, are another form of cascading use. Paper is one of the most commonly recycled materials globally: the industry has achieved a recovery rate of more than 60 percent in Europe and Northern America, nearly 50 percent in Latin America and the Caribbean and Asia and the Pacific and just under 30 percent in Africa.307 A recent analysis found that achieving the maximum technical recycling potential of waste wood and paper would increase the wood-use efficiency ratio in the European wood sector by 31 percent, leading to a concomitant reduction in GHG emissions of 52 percent.308 Thus, while increasing resource efficiency is feasible, regional disparities persist. Capacity development, technological and design innovation and a conducive policy framework are needed to increase material efficiency globally by improving the technological and social infrastructure.309
Biobased industries cater to a wide range of needs with environmentally friendly products and add value to resources
Forests and trees provide renewable raw materials for a host of manufacturing industries that produce a wide range of bioproducts; some (e.g. wooden furniture, pulp and paper, cork, bamboo, rattan, medicinal plants and resins) have been in use for millennia, and others (e.g. wood foam, textile fibres and bioplastics) are the result of recent innovations. Renewable bioproducts allow the substitution of GHG-intensive products.310
The non-food biobased industries are estimated to grow at 3.3 percent per year to 2030, when their output is projected to be worth USD 5 trillion.311 A diverse range of forest-based bioproducts contributes to the global bioeconomy, some of which are described below and in Box 15.
▸ A wide array of biochemicals can be manufactured from biomass, such as adhesives, lubricants, surfactants and emollients. Biochemicals are considered a growth sector, with the global chemicals industry generating an estimated EUR 4.01 trillion in 2020.317 Significant opportunities lie, for example, in the kraft lignin segment, in which only 1–2 percent of residues are currently converted into higher-value products.318
▸ Bioplastics can be produced using lignin and industrial side streams from the pulp-and-paper industry. Bioplastics currently represent only 1 percent of the total volume of plastics produced annually. The current production capacity of second- and third-generation feedstock bioplastics derived from crops and plants not suitable for food or feed (e.g. trees), waste from first-generation feedstock (e.g. bagasse and waste vegetable oil) and algae is estimated at 2.3 million tonnes; production capacity is projected to grow to 4.3 million tonnes by 2022.319
▸ The production of manufactured cellulosic textiles (typically derived from wood or other plant-based material) is projected to rise from 6.4 million tonnes in 2020 to 8.6 million tonnes in 2027.320 Such wood-based textiles could have a substitution factor as high as 2.8.321 According to a recent scenario-based estimate, global roundwood production would increase by 81 million m3 by 2040 if wood-based fibre met 30 percent of total textile fibre demand.322
Box 15 Use of wood fibre in the manufacture of medical products
The COVID-19 pandemic has dramatically increased demand for a range of medical products, particularly personal protective equipment such as gowns, masks, surgical drapes and bed sheets, which are typically made of non-woven polypropylene but can also be made with wood fibre. A paper membrane made of highly crystalline cellulose nanofibres can filter virus particles and thus mitigate their spread.312 Fully compostable and biodegradable medical masks have been developed using wood fibre.313 Wood fibre can also be used in biobased value chains to manufacture hygiene papers, hand sanitizers, soaps, toothpastes and diapers, and there have been advances in the development of low-cost wound dressings made of wood-based nanocellulose.314,315 Demand for health supplements extracted from forests grew dramatically during the pandemic. In the United States of America, for example, sales of herbal dietary supplements for immune health, stress relief and heart health increased by 17.3 percent between 2019 and 2020, to USD 11.3 billion; top-selling supplements contained black cohosh (Actaea racemosa), açai (Euterpe oleracea), ginseng (Panax spp.), Garcinia gummi-gutta and mushrooms (Cordyceps spp.).316
Forest-based bioenergy needs to become more efficient, cleaner and greener
Energy production is the major use of wood globally; more than 2 billion people will still rely on the traditional use of woodfuel and other types of biomass energy for cooking by the end of the present decade, especially in the world’s most impoverished regions.323
In some areas, demand for woodfuels, including fuelwood and charcoal, exceeds the sustainable supply capacity of forests and trees, leading to forest degradation and loss. According to one estimate, 27–34 percent of woodfuel extraction in pantropical regions is unsustainable, and approximately 275 million people live in woodfuel-depletion hotspots in South Asia and East Africa.324 The gap between demand and sustainable supply can be bridged by the restoration of degraded forests, the establishment of fast-growing tree plantations, improving the use of residues from wood harvesting and processing, and the recovery of post-consumer wood through its cascading use within a more circular economic framework. Plantations can reduce pressure on natural forests and woodlands325 near major charcoal demand centres, such as urban areas in sub-Saharan Africa.326 A recent technical and economic feasibility study on industrial charcoal production in the Congo estimated a 10.7 percent financial return on investment based on the establishment of tree plantations, the additional production of briquettes using dust created by charcoal production, and the use of clean, efficient charcoal kilns.327
National woodfuel strategies are important for coordinating actions across government agencies and ensuring that interventions produce positive economic, social and environmental impacts. Malawi’s National Charcoal Strategy (2017–2027), for example, presents a multisectoral framework for addressing problems in charcoal production and demand in the near, medium and long terms, aligning with other national strategies and policies that promote broad objectives aimed at reducing deforestation, forest degradation and dependence on solid biomass fuels.328
Modern applications of woodfuels typically include the heating of residential and commercial buildings (as either standalone or district heating facilities) and use in industrial processes; electricity generation and the cogeneration of heat and power (by the direct burning of woodfuel or co-firing with coal); and the production of liquid fuels for the transport sector.329 There is considerable interest in increasing the use of bioenergy to help achieve net-zero emissions in the energy sector (Box 16). Burning forest biomass returns to the atmosphere only carbon that plants have absorbed as they have grown; burning fossil fuels releases carbon that has been stored in the ground for millions of years. Nevertheless, there are environmental concerns about the further use of wood biomass for bioenergy production associated with GHG emissions, soil-quality degradation and biodiversity loss. Therefore, there is a need for environmental, economic and social sustainability in bioenergy production, which can be assessed through a set of multicriteria indicators, and life-cycle assessment can be used to explore environmental performance.330 Although the full impact of woodfuel on climate change is disputed,331 there is little disagreement that benefits can be maximized by applying sustainable forest management practices and increasing the operational efficiencies of combined-heat-and-power plants and biorefineries.
Box 16The potential role of biomass in achieving net-zero emissions by 2050
The International Energy Agency (IEA) (2021) sets out a roadmap for the global energy sector in which modern bioenergy, especially woodfuels, would play a key role in achieving net-zero emissions – modern bioenergy use would increase by around 60 percent between 2020 and 2050 alongside a shift away from the traditional use of biomass.332 Under the IEA’s net-zero-emissions-by-2050 scenario, the land area for dedicated biomass plantations would need to increase from 330 million ha in 2020 to 410 million ha in 2050. Increasing biomass production by 60 percent in 30 years to meet bioenergy production goals will require a comprehensive set of policies, strategies, regulations, management measures and financial resources to ensure that such additional biomass production is sustainable and does not cause economic, social or environmental harm, such as the loss of soil quality and biodiversity.
Raw-material demand for energy can be reduced by increasing efficiency in the woodfuel conversion and utilization processes. This can be achieved by improving the properties of wood residues through the production of wood pellets and briquettes; increasing woodfuel processing efficiency with improved charcoal production kilns; improving woodstove thermal efficiency; and increasing access to modern energy forms, such as electricity (including renewable forms, such as solar and wind), liquefied petroleum gas and biogas from organic wastes. Various innovative efforts – such as those in the Venture Catalyst portfolio of the Clean Cooking Alliance333 – are underway to encourage the clean and efficient burning of woodfuels and reduce woodfuel demand. In some countries, transitioning to modern woodfuels could have profound livelihood implications (Box 17).
Box 17Woodfuel and employment in Nigeria
In many developing countries, the transition to improved energy access and modern renewables may have implications for livelihoods. In Nigeria, where biomass is the largest source of total primary energy supply, about 40 million people (i.e. one-fifth of the population) are engaged directly in fuelwood collection and charcoal production, which provides an estimated 530 000 full-time equivalent direct jobs. An additional 200 000 people – mostly also full-time – provide transport services for retail and wholesale trade.334 Large numbers of livelihoods in other sub-Saharan African countries also depend on the fuelwood and charcoal economies.335