Scientists at the University of Stellenbosch have completed a research paper concluding that treated timber is a “climate-friendly” resource, in dramatic contrast to the alternatives.
This comes amid growing acknowledgment that plantations can be classed as carbon-capture projects. Our customer Green Resources has had three such projects and is looking out for new ones on its undeveloped land, while The New Forests Company, also a customer, has an innovative carbon-capture project in Uganda that takes a landscape approach, and includes community and conservation areas.
The authors of the research paper, Dr Philip Crafford and Prof Brand Wessels, summarised the international literature, adapting findings for South African conditions. They concluded that a 1m3 treated timber utility pole sequesters between 186kg and 572kg of CO2 equivalent gases over its total life cycle.
This is a dramatic advantage over poles manufactured from concrete, galvanised steel, and fibre-reinforced composites, which caused the emission of 1462kg, 789kg, and 862kg of CO2 equivalent gases respectively, per cubic metre.
The total life cycle considered was from “cradle to grave”, encompassing growth, processing, transport, service life, reuse and recycling or disposal.
“Knowledge of the greenhouse gas emissions from different products and processes is essential for making informed decisions.”
“Climate change … is considered by many to be one of the biggest threats to humanity. Knowledge of the greenhouse gas emissions from different products and processes is therefore essential to make informed decisions,” wrote the authors in their report.
“It is good for the planet to use renewable wooden poles and timber from a sustainable source, i.e., Forest Stewardship Council-certified plantations, instead of carbon-intensive and non-renewable materials such as concrete and steel, as far as possible,” said Dr Crafford in an interview with the Dolphin Bay Brief.
While the timber industry realises the climate advantages of timber, those making choices between the various materials – from utility parastatals to the construction industry, farmers, and members of the public – might not, he added.
The research was a desktop review of research from Australia, the USA and Norway. The authors adapted the findings for South African conditions, considering, for example, the differences in wood densities. Conservative values were used to consider the South African timber equivalents.
Poles from plantations in East Africa are likely to have similar impacts to those grown in South Africa, as their eucalyptus and pine species and treatment methods are similar, Dr Crafford said.
When timber poles are used in a typical agricultural setup such as a vineyard or orchard, between 1732kg and 8455kg of CO2 equivalent gases are sequestered. The type of transport used, and the distance travelled affect the total emissions of timber use. The report authors recommend that timber should be sourced locally, and the most efficient means of transport used.
“Transport impact plays a significant part in the overall life cycle impact of materials. However, since wood stores carbon and is relatively light per volume, wood transport impacts are usually not as significant compared to other denser materials, such as concrete and steel.”
The emissions from shipping treated timber were found to be far lower than those from trucking. For a similar emissions impact, one ton of timber poles could be transported 1000km by truck or 8000km by container ship.
Trees and wood consist largely of carbon-based compounds formed through the photosynthetic process of absorbing CO2 from the atmosphere.
Dr Crafford explained that calculations for the carbon sequestration capacity of timber are based on pre-existing knowledge of the density of various timber species and of how much carbon is stored in them.
“Trees and wood consist largely of carbon-based compounds which were formed through the photosynthetic process of absorbing CO2 from the atmosphere,” the report stated. “Poles are one of the wood-based products where the least processing energy is required for final product manufacturing.
“It is therefore unsurprising that the use of both untreated and treated timber poles can result in significant net carbon storage.”
Read the full story on the SAWPA website.