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Evergreen: New Study Provides Life Cycle Assessment Answers for U.S. Hardwood Lumber
New study provides scientific basis for analyzing the life cycle impacts of U.S. hardwoods from cradle to gate assessments. This research should help position the industry to compete as Europe starts imposing more LCA requirements, and green building standards embrace more scientific-based assessments in the United States.
By Michael Snow
Date Posted: 11/1/2012
The U.S. hardwood industry has a new scientific resource to tell its story when it comes to assessing the environmental impact of wood products. Based on a study conducted by sustainability experts Anonymous OSHA safety tools identify workplace hazards. pg. XXPE International, the American Hardwood Export Council (AHEC) has developed a Life Cycle Assessment (LCA) of rough-sawn kiln-dried hardwood lumber.
This study fills in all of the blanks. It covers the environmental impact of extracting wood from the forest, manufacturing it into lumber, and delivering it to a foreign port. We also are going to come out with similar figures for veneer later this year. Various users of hardwood lumber can then take this information to produce full cradle to grave LCAs on finished goods. A key aim of the study is to enable manufacturers of joinery, flooring and furniture products that rely on American hardwoods to prepare formal Environmental Product Declarations (EPDs) in line with international standards.
EPDs are widely recognized as the most effective method of communicating the full environmental profile of any given product or material. Green building initiatives like BREEAM (UK and International), LEED (U.S. and International), DGNB (Germany), HQE (France), and CASBEE (Japan) are becoming more dependent on EPDs to provide credible and comparative information on the environmental performance of materials used in the building sector.
Also, policy experts, architects, designers and others can use the scientific information to make ecologically smart decisions about the environmental impact of buildings and products constructed of American hardwoods. Depending on which materials and which impacts you are comparing, wood compares very favorably to pretty much any other material that has ever been studied.
The AHEC report provides quantitative data on Global Warming Potential, Acidification Potential, Eutrophication Potential, Photochemical Ozone Creation Potential, and Ozone Depletion Potential. It also provides a qualitative assessment of toxicity, biodiversity, land use and land use change, and water resource impacts. The report includes a sensitivity analysis to show how environmental impacts vary according to key factors such as species, lumber thickness, and transport distance and mode.
The report is an essential requirement for use of AHEC’s LCA data in science-based assessments of the sustainability of U.S. hardwood lumber compared to other wood and non-wood materials. It has been peer reviewed by a group of international experts and found to be solid in adhering to ISO 14040 and ISO 14044 standards. It also underpins on-going collaborative work by AHEC and PE-International to develop innovative computer-based systems for modeling environmental impacts of wood material choices in product design.
The peer review panel commented on the study, “One of the outstanding features of the study is the broad coverage of American hardwood species. The 19 different species addressed represent more than 95% of the hardwood species harvested in the United States by volume and more than 95% of the wood volume exported by AHEC members. Another positive feature of the study is the substantial share of primary data collected to reach representative results for American hardwood lumber. Primary data were collected from 46 AHEC companies, representing approximately 20% of AHEC members and approximately 12% of the hardwood lumber production volume. Due to the substantial share and relevance of the primary data, the data quality is considered to be high”.
By 2015 in Europe, all building materials will need to have EPDs. And by 2017, all consumer products will need to have EPDs. The AHEC –sponsored research will help companies using American hardwoods to comply with these requirements. Just as EPDs are in the process of being required in the EU, I have to believe they will be required in the United States as well in the not too distant future.
The two major factors that impact the LCA of American hardwoods are the energy used to kiln dry lumber and the energy used for transportation. This is because kiln drying is the most energy intensive part of the hardwood lumber process. Also, the mode of travel and the distance required to go from harvest to processing to the end user impacts the total environmental footprint.
Key variables in the kiln drying process include the efficiency of the kiln, the thickness of the lumber, the use of wood waste versus pulling energy off the grid, etc.
Beyond preparing American hardwood users to meet international requirements, the AHEC LCA may impact domestic markets as green building standards in the United States rush to catch up with Europe. This research is adding fuel to the fire if LEED is going to look to change its point system to incorporate LCAs. Right now you only get the benefit in LEED for wood if you bring it from less than 500 miles or it is FSC certified. You don’t get benefit from the environmental credentials of the wood itself. This type of scientific data is going to be harder and harder for LEED to ignore.
LCAs and EPDs are pushing LEED and the green building standards to use more science-based analysis and to compare apples to apples. Currently, LEED has placed stricter analysis requirements on wood compared to other products when it comes to tracing the extraction and environmental impacts of raw materials.
Let’s be clear. This is not a measure of sustainability as far as the forest products are concerned. There are other tools to measure those factors including certification standards, government data, etc. This is a measure of the environmental impacts of the processes themselves. Our conclusions are equally true even if the wood was illegally harvested.
Although this report doesn’t really cover the issue of carbon sequestration, another major factor that favors wood products. Different countries are classifying carbon sequestration in different ways. It all comes down to the life expectancy of the product. If you have wood in flooring or in a chair, that is around longer than it takes for regeneration of that tree. Let’s say a 50 year cycle. Then that product would be carbon negative for life. If you have something from IKEA that is storing carbon for a year or two and is disposed of because it was used in a dorm room, then the long-term life expectancy is different. How you calculate carbon storage depends a lot on the finished product and how long it is in use.
The big picture benefit of wood is that there is no other material that has that carbon stored in there and gives you that option to deliver a product to market in a carbon negative way. No other material starts with a carbon negative capability. Where you take it from there depends on the manufacturers, the designers and architects. If you design with wood, you are starting off with a carbon negative product or material. If you find a more efficient way to do it or a way to make it last longer, then you are minimizing the impact. When you compare wood to any other material, there is a night and day difference.