The ‘Wood Miles’ Question
Canada Wood frequently receives information requests from enquirers asking the ‘wood-miles’ question? This always comes as somewhat of a surprise considering the small amount of energy required to transport wood around the world relative to the amount of energy used to manufacture alternative construction materials. Nevertheless, it is a question that deserves to be addressed.
As trees grow they absorb carbon dioxide from the atmosphere and release oxygen. In a real way wood is made from captured carbon, and wood products continue to store it over their lifetimes – even longer when recycled. A study* on the carbon footprint of wood products manufactured in British Columbia – the western most province of Canada – and delivered to the UK shows that despite being transported more than 16,000 kilometres these products represent a net carbon sink on delivery; in fact the emissions of CO2 associated with harvesting, manufacturing and transport to the UK represent less than one-third of the amount of CO2 stored in the wood products themselves.
Britain uses large amounts of timber, paper, boards and other wood products each year, of which around 85% has to be imported**. With the UK being a mere 15% self-sufficient in timber, and the large majority of home-grown production most suited for use as pulp, fencing and generally lower-grade structural applications, substantial quantities of wood must be imported from somewhere, just as the UK has been doing for centuries and from some 80 countries. The alternative to importing wood is to address the shortfall with increased use of non-renewable materials, many of which will have been imported themselves!
Given that we have to purchase wood products from somewhere, once having made a selection then the main focus should be to ensure that it is obtained from legal, sustainable and dependable sources. Canada is a traditional and dependable supplier of familiar and sustainably produced wood products, and will continue to be so. Manufacturers in Ontario and Quebec are able to supply sawn timber in a variety of softwood and hardwood species such as spruces, pines, maples and oaks. Furthermore, factory-built homes, engineered wood products, mouldings, wood floors and other finished and semi-finished wood products are available from these provinces. So not only can the UK benefit from access to Canada’s renewable and sustainably managed wood resource, accounting for some 10% of the world’s forest area, it can gain from the expertise learned from constructing buildings in some of the world’s most extreme climate conditions.
Britain is increasingly harvesting home-grown exotic species planted commercially over a century ago; and while they may be the same species as those imported, grown outside their natural habitat the wood from these trees can be very different in both appearance and performance. Whilst it may seem to make perfect sense to source from ‘just along the road’ to reduce the ‘wood miles’ and whilst it might also cost less to purchase locally, it always pays to ensure that it matches expectations! Importation gives us access to the vast selection of wood species that is available from across the globe, each with their own unique combinations of properties and in qualities that make them ideally suited to particular end-uses.
So, do people ask the same question in relation to other materials? What about steel miles, concrete miles, PVCu miles or brick miles? These products involve massive release of carbon dioxide just in mineral extraction, processing and production, let-alone in their transport to market. And of course the fossil fuels used in their production also have to be transported from oil and coal producing countries to the points of production.
In practice wood is best used in combination with other materials, each used to best advantage according to circumstance. As designers and engineers become more familiar with the environmental credentials of wood, the wood species and grades that are available to them from throughout the globe, and the new engineered-wood solutions that are being developed then one could hope for and indeed expect much greater use of one of the world’s few genuinely renewable construction materials.
*A Carbon Footprint of Four Canadian Wood Products Delivered to the UK
**Forestry Commission GB
Many thanks must go to our funding Partners: Natural Resources Canada Wood Export Program (CWEP), & Forestry Innovation Investment Ltd. (FII).