The Hidden Carbon Source: Timber
Toward a Sustainable Future
Few objectives are as grand and worthwhile as working toward a sustainable future in materials and structures. The present is in the midst of a paradigm change toward that goal with growing involvement by all stakeholders - owners, designers, builders, and manufacturers. That’s a good thing, and Angelus Block fully embraces every opportunity to contribute to those efforts.
Cement Bad, Wood Good?
Since the beginning of sustainable movements, the cement industry has been seen as a high-profile source of GHG emissions. To its credit, the industry has mobilized to advance improvements in manufacturing, formulations, usage, and alternatives to reduce impacts.
Non-cementitious industry groups, particularly of renewable plant-based products, launched major promotional campaigns proclaiming superior sustainability. On the simple premise that if you can regrow it, it’s renewable, and if it’s renewable, it’s sustainable and preferred, even governments bought in to fund programs for a behemoth industry group - timber - to expand the use of wood, including tall buildings.
However, simple is rarely that simple, and single attributes are not the whole story. Life itself is holistic and exists within the reality of functional trade-offs by which a species survives. So, too, if we are to truly assess the sustainable and resilient properties of a building system, we cannot isolate narrative-convenient data, but must look at the whole of its contributions, both positive and negative. (Please see studies and articles related to cost comparisons and fire safety in this section, and wide-ranging articles in Sustainable and Resilient Design.)
Beside other problematic life safety and resilience issues with wood construction, a recent study reveals the hidden side of timber.
Timber a Major Source of GHG
A study1 by researchers based at Oregon State University and the University of Idaho confirms findings by the Center for Sustainable Economy’s 2015 and 2017 research that the primary source of GHG in Oregon is logging1,2.
Incredibly, timber harvest emissions are not reported. A “carbon flux” accounting system devised by the timber industry essentially grants an automatic offset for carbon sequestered carbon, thus escaping emissions reporting required of other sectors3.
Further, logging emits more carbon nationwide than the residential and commercial sectors combined. The Oregon Forest Carbon Policy brief3 calculated timber harvest related emissions from:
- CO2-e removed from site by timber harvest
- CO2-e removed from site and stored in long-lived (100+ years) wood products
- Foregone sequestration from recently clearcut lands
- Decay and combustion of logging residuals
While wood products certainly offer value in appropriate uses, caution should be given to its carte blanche acceptance as a sustainability-preferred building material. Corroborating studies expose timber’s substantial GHG impacts, and considered with life safety, resilience, and cost factors, it is clear timber’s reputation as a sustainable icon is not based on a holistic appraisal.
1Law, et al. (2018). Land use strategies to mitigate climate change in carbon dense temperate forests