The Facts: Sustainability, Wood and the Environment
Some in the building and design community have seen a regurgitated “white paper1” that includes inaccurate claims about wood. While its bias toward competitor materials and goal of attacking wood is clear, it has nevertheless generated questions. Below we correct the inaccurate claims:
|Claim: “The environmental impacts of tree species vary based on several factors.”
||Fact: It’s true that not all trees are the same (even within a single species or sub-species), but all trees, our basic commodity, are bio-based and renewable. You can’t get much more bio-based than using wood as the primary raw ingredient.
The American Wood Council has been involved in the sponsorship and promotion of life cycle assessment (LCA) as a tool for calculating the environmental impacts of wood products. To date, AWC has been involved in the development of 12 environmental product declarations (EPDs) of North American wood products. These EPDs are based on product category rules (PCR) for North American wood products2 published by FPInnovations and are subject to third party peer‐review and verification to ensure compliance. The FPInnovations PCR (FPI PCR) aligns LCA on wood products in North America and is compliant with the ISO 21930 Sustainability in Building Construction standard and draws heavily on PCRs for wood products in other jurisdictions (as recommended in ISO 14025).
The North American Softwood Lumber EPD is representative of the most common species and grades of lumber used in building construction. The environmental impacts attributed to these individual species are weighted by market share. Therefore, the claim by AISC is baseless, since industry wide EPDs take this into consideration.
|Claim: “Any analysis of the environmental impact of engineered wood products needs to include the manufacture and ultimate disposal of these chemicals, as well as their potential effects on building occupants due to off-gassing and in fire exposure.”
||Fact: They do. The EPDs developed by AWC for composite wood products include all component materials and the production impacts of their underlying chemicals. The environmental impact categories reported in the North American wood product EPDs and the life-cycle assessments on which they are based are identical to those included by every other major building product industry developing and releasing EPDs, as they all must comply with the ISO 21930 Sustainability in Building Construction standard.
Off gassing is not an issue for structural wood products, as evidenced by the California Air Resource Board and EPA in their respective composite wood product rulemakings.
|Claim: “Environmental claims based on an assumption of sustainable management and harvesting only apply to wood products from those [certified] forests. The majority of U.S. forests do not meet this requirement.”
||Fact: One important fact to note is that 300 million acres (approximately 20%) of U.S. forests are certified 3…not 7% as claimed. However, according to American Forest & Paper Association data on their members, 96% of all fiber has come through a sustainable procurement system such as Sustainable Forestry Initiative’s (SFI) fiber sourcing program, not the 12% claimed. In addition to that, state-required (mandatory) and voluntary Best Management Practices (BMPs) help protect water quality and species, and implementation rates are an average of 91% nationwide.4
Sustainably managed land doesn’t mean certified. There are over 24 million acres of family-owned forests in the U.S. that are privately managed for enjoyment with occasional small amounts of timber harvested for forest health or wildlife.
And, it is recognized and disclosed that LCA is not a substitute for sustainable forest management. The industry’s wood product EPDs make no claims about the sustainability of the upstream forest resource supply beyond citing biogenic carbon stock trends and requiring that it not be declining. The following language is required to be included in all wood EPDs in compliance with wood FPInnovations Product Category Rules (PCR), the basis for EPDs:
LCAs do not generally address site ‐ specific environmental issues related to resource extraction or toxic effects of products on human health. Unreported environmental impacts include (but are not limited to) factors attributable to human health, land use change and habitat destruction. Forest certification systems and government regulations address some of these issues. The products in this EPD conform to: state, provincial, regional, and national regulations and forest certification schemes.
The product category rules for North American structural wood products requires that there be no land use change and that the national forest carbon stock in the source nation be non-declining. This methodology is consistent with the European PCR for wood products EN 16485. The number of forested acres in the U.S. has remained stable or rising for the past 100 years, even while the country’s population has quadrupled.
|Claim: “A similar assumption is that the carbon uptake in an acre of new seedlings is the same as the carbon uptake in an acre of mature forest land. … Any study of wood’s environmental impacts, even in sustainably managed forests, must account for the difference in carbon dioxide (CO2) sequestration rates between young and old trees.”
||Fact: The statement that “not all forests have equivalent carbon pools” is correct and North American wood industry LCA practice does not assume they are equivalent. As directed by the PCR, what must be considered is the net flux of carbon and not a proxy indicator such as an area of forest, since density and size of trees in any given acre would vary carbon uptake. However, area can be used as a proxy for carbon storage – which implies equivalent carbon pools in different areas,
The U.S. Department of State reports, based on EPA and USDA analysis, that strong demand for forest products other than timber will increase forest carbon stocks through ongoing landowner investment.5
And in the U.S., twice as much wood is being grown each year as is harvested6 with the total volume of trees growing in U.S. forests has increasing 50% in since the 1950s.7 The steady and increasing North American forest carbon balances include all carbon pools from the Intergovernmental Panel on Climate Change (IPCC) Good Practice Guidance for Land Use, Land Use Change and Forestry. By demonstrating the sustainable carbon balance, the emissions of biogenic carbon are cancelled by forest growth and the permanent storage of biogenic carbon is additional and is explicitly permitted to be accounted as a net emission reduction.
|Claim: “Any analysis of the environmental impact of wood must account for emissions related to incineration as they do not reduce net environmental impacts.”
||Fact: Use of biomass for energy lessens dependence on fossil fuels, which release carbon into the atmosphere without a natural way to capture and recycle it.
AWC member companies account for, on average, 75 percent of their energy use from biomass, most of which is derived from manufacturing residuals.8 Using manufacturing residuals captures energy value that would otherwise be lost to the atmosphere, and at the same time displaces fossil fuel use, and avoids additional methane emissions that would occur if residuals or other biomass was landfilled.
The debris that is mentioned is an important part of maintaining cover for wildlife, as well as soil and water quality on site, and there are Best Management Practices that companies must follow specifically to leave behind this essential material after harvest.
|Claim: “Any evaluation of wood-related environmental impacts must take into account the actual levels of waste being generated on both a pre-consumer and post-consumer basis, as well as the impacts related to the material’s disposal.”
||Fact: There is little waste associated with wood product manufacturing. Every piece of the log is utilized, but that use varies by region. In some instances, saw dust is used to make engineered wood panels while in other regions it may be burned for energy. Unlike steel manufacturing, there is no pre-consumer waste that needs to be re-introduced to the process for it to have value.
Additionally, many states have requirements for leaving a certain amount of material behind after harvest. Bark, tops, and stumps left in the forest after a harvest help maintain soil and water quality, and provide cover and nutrients for species.
The wood products industry has many manufacturers located across North America with many products shipped to secondary manufacturers who make new wood products. Because there is no way to predict what a wood product might become after leaving the original manufacturer, the industry EPDs are intended to characterize the environmental performance of products during their control, or “cradle-to-gate” (from raw material harvest through when the finished product is ready to leave the manufacturing facility). With an infinite number of potential final products, it is not feasible to make reasonable assumptions about their use-phase impacts. Accordingly, these EPDs do not cover the gate-to-grave phase of their life cycle; however, secondary manufacturers are encouraged to produce EPDs on their products.
Importantly, the wood industry has in place programs for addressing product end-of-life, including a network of reuse and recycling facilities, along with the ability to convert these products to biomass energy to substitute for the fossil fuels used to produce many other building products. (www.reusewood.org)
|Claim: “… any claim of carbon sequestration must be made on a net rather than absolute basis.”
||Fact: It is industry practice to report sequestered carbon on a net basis after a 100-year useful product life. The Carbon Impacts of Wood9, which provides the standard wood industry calculation methodology, clearly shows greenhouse gas emission savings for a range of wood products based on cradle-to-gate output minus the carbon storage associated with the useful life of the product. As shown, the wood products industry does in fact use a net basis for reporting carbon sequestration.
1 American Institute of Steel Construction (May 2019). Caveat Emptor: Sustainability, Wood and the Environment.
2 Product Category Rules (PCR) For preparing an Environmental Product Declaration (EPD) For North American Structural and Architectural Wood Products UN CPC 31 NAICS 321: https://fpinnovations.ca/Extranet/Pages/AssetDetails.aspx?item=/Extranet/Assets/ResearchReportsWP/3064.pdf
American Forest & Paper Association. (March 2016). Sustainable Forestry and Certification Programs in the United States.
National Association of State Foresters. Protecting Water Quality through State Forestry Best Management Practices.
2016 Second Biennial Report of the United States of America Under the United Nations Framework Convention on Climate Change, December 2015.
U.S. Forest Service 2010 Resources Planning Act Assessment
U.S. Energy Information Administration. http://www.eia.gov/energy_in_brief/article/renewable_electricity.cfm
The Carbon Impacts of Wood. Forest Products Journal 64(7/8): 220-231. 2014.