American hardwoods leave a tiny carbon footprint, a new study confirms

A facility converting wood into usable building products. Photo credit: American Hardwood Export Council

A new life cycle assessment (LCA) study that was commissioned by the American Hardwood Export Council (AHEC) – the American hardwood industry’s leading international trade association – has uncovered American hardwood’s powerful environmental benefits, with its sustainability, positive impact, and small carbon emission, among others.

American hardwood lumber that has been kiln-dried showed that the carbon sequestrated during its growth as a tree more than offset the total carbon emission calculation during its extraction, processing, and shipment all the way to India from the United States of America (U.S.A.), the study revealed.

Moreover, the research study highlighted the fact that transportation via ocean is a considerably smaller factor in the overall carbon footprint American hardwoods left behind than previously thought. Crucially, during the processing, there was a heavy dependence on bio-mass rather than fossil fuel, keeping the overall carbon footprint for the American hardwood down.


Designers who advocate sustainable living are not promoting the latest fashion trend, nor are they looking to minimise the impact of their creations on the earth’s environment; instead, they are promoting their desire for people to want to live in a sustainable way. In doing so, designers become a vital part of the process of moving towards a future that is more sustainable for all.

In choosing their materials, the designers have the opportunity to minimise their impact on the environment through all the stages of the product life cycle, from extraction through processing, use, and reuse, and all the way to disposal – all while also reducing waste and maximising the use of hardwoods.

Right from the point of extraction, AHEC has proven that American hardwoods have a very low impact on the environment throughout all the stages of their product life cycle. Forest management is not intensive due to the fact that most American hardwood forests are managed and owned by small companies, families, or even individuals, rather than large timber organisations.


A resource that is still expanding
Economic return and timber production among American hardwood shareholders are not the top priorities, the forests are usually managed less aggressively, and the forests are allowed to grow on longer rotations. Frequently, harvesting tends to be selective, where a scant few trees per hectare are felled, as compared to clear-felling.

After the harvesting, the forest owners would usually depend more on natural regeneration, something abundant in the deep fertile soils found in the U.S.A., and thus does not need much in the way of additional chemical fertilisers.

Regular inventories taken of the forests by the federal government every decade has clearly shown that American hardwoods are renewable as well as expanding as a resource. According to the data released by the U.S. Department of Agriculture in 2009 in preparation for the upcoming inventory report in 2010, from 1953 to 2007, the volume of American hardwood growing stock more than doubled from 5 billion cbm to 11.4 billion cbm. In the fifty years where the timber harvesting was at its most intensive in the U.S., the hardwood growing stock consistently grew. Additionally, the survey proved that the forests were allowed to age, with more trees permitted to grow to full size before harvesting – to prove it, the volume of hardwood trees with a diameter of 48 centimetres or more tripled.


A positive impact
American hardwoods are one of the few material which leaves a positive impact on the environment – a sharp contrast to concrete, plastic, and steel, where efforts to bring down their negative impacts on the environment are frequently underlined.

Management of American hardwood forests over a long term for sustainable timber production has proven to make a notable contribution to carbon storage, storing approximately the equivalent of 165 million tonnes of carbon dioxide – excluding harvested hardwood – every year for five decades. Additionally, this staggering contribution to carbon sequestration does not include the carbon held in long-term storage, a component of American hardwoods. With useful product lives spanning entire generations, cabinetry, flooring, and furniture made of American hardwoods also store carbon for decades more.

On top of that, the process that converts wood into products that can be utilised in building does not need as much as energy as many other materials. Moreover, most of the energy required to make American hardwood products is bio-energy. A study in 2007 on 20 hardwood sawmills concluded that 75 per cent – or three quarters – of the energy needed to product kiln-dried American hardwood lumber was acquired from bio-mass – that is, daw dust and tree bark – effectively emitting far less carbon dioxide than the production of many other recycled materials.


A miniscule carbon footprint
An assessment of the carbon footprint left behind by American hardwoods from the forest all the way to European distributors showed that the carbon sequestration that happened during the tree’s forest growth more than offset the total carbon emissions derived from its harvesting, processing, and transport, with transport having a relatively minor effect on the overall carbon footprint, and especially when transported via ocean.

Transporting the American hardwoods across the Atlantic to Europe – a distance of over 6,000 kilometres – takes up little more energy than a journey of 500 kilometres made over land.

There are also minimal health risks related to a natural material much like American hardwoods, which needs no glues or other chemical treatment during its processing. They are also easy to maintain and upkeep with non-toxic cleaners and they do not trap dirt, dust, or even other allergens, and can be kept allergen-free through simple regular maintenance procedures, like mopping, sweeping, and vacuuming.


And a commercial “afterlife”
One of the key principles of sustainable designs is ensuring that the products, processes, and systems should be designed with a commercial “afterlife” in mind, and can be linked to a new trend regarding bio-mimicry, which involves the re-design of industrial systems based on biological lines, and thus allowing the constant reuse of the materials in question in continuous closed cycles.

But because they are untouched by other materials and chemicals, the most effective, direct method to realise bio-mimicry is through natural, organic, renewable materials like American hardwoods – which are readily recyclable and reusable even after a building’s life span. And hardwood floors are capable of lasting up to 50 years and more, compared to tile and broadloom, which usually only lasts six years.

American hardwoods are also biodegradable and non-toxic, and can be incinerated safely.


Source: American Hardwood Export Council