Seminar: Evaluating Greenhouse gas (GHG) abatement relating to timber in construction in the UK

Dr Morwenna Spear gave a talk about greenhouse gas emissions related to timber construction in the UK.

First, she talked about the recent importance of climate change and how it is key for the issue the seminar was about. Dr. Spear pointed out that timber can be thought of as biomass as well as a structuring material. Then she talked about the “Wood in Construction Report”, which had four co-authors: professor Callum Hill, Dr. Andrew Norton, Professor Colin Price and Dr. Graham Ormondroyd; of which two had already been at Bangor University.

We saw a graph showing the progress achieved in reducing greenhouse gas emissions during the past years, which was considerable, especially regarding industry and power sectors. Another graph showed the carbon emissions in the built environment from 1990 and how they had been reduced until the present days, including how they are expected to be reduced until 2050. The reduction seems to be considerably significant.

 

So, what’s the purpose of forestry in the UK?

The demand for timber is set to increase. Timber production involves a sustainable production and renewable material, as it has an excellent carbon profile (i.e. potential for a low embodied carbon material: it takes less energy than some other competitive products; and high sequestered carbon content, keeps carbon out of the atmosphere)

Also, there is a demand for renewable biomass for energy and recyclable materials in a circular economy. Furthermore, the wood-based panels demand is gradually increasing with time.

Morwenna explained that as buildings become more energy efficient, the importance of the energy and carbon associated with construction materials will become more prominent, therefore there is an increased importance in designing efficiently with the materials resources, as well as an increased consideration of embodied carbon or global warming potential (GWP) of buildings at build stage.

But, what is the embodied carbon? Embodied carbon is the CO₂ burden associated with the production processes. For wood, this could include forest activities, extraction and transport, etc.

A model was developed for annual housebuilding to investigate global warming potential (GWP) of new build, assumed approx. 190,000 dwellings per year, assuming 28% of dwellings were timber-framed. I didn’t pick up this part very well since it was about topics which seemed unfamiliar to me, but what  I understood is that the reinforced concrete had the most embodied carbon, however, bricks and other material types also had a certain quantity of it.

All scenarios with increased use of timber led to a reduction in the embodied carbon compared to those with no growth in timber. They also stored a greater volume of sequestered carbon within the built environment than the no growth case.

Accounting for demolition timber apparently had only a small impact on the volume of stored sequestered carbon in the built environment. This was due to the number of new houses built being significantly larger than the number of demolitions.

Some things to point out–housebuilding is a relatively minor component of construction in greenhouse gas emissions–non-residential structures also require action.

The conclusions of the talk were:

·The use of mass timber building systems can both reduce embodied carbon and increase the stored sequestered CO₂.

·Material choice can be related to global warming potential using Environmental Product Declarations

·Details such as cladding materials, roof covering, etc, can alter embodied carbon of buildings

·Timber framed systems offer an increase in quantity of stored carbon and a reduction in embodied carbon.

Personally, this talk did not particularly catch my attention since is not exactly related to my course–I am a Zoology student. However, it gave me some information I did not know beforehand on carbon emissions and industry which I might find useful.