Trees soak up carbon dioxide, trees store carbon dioxide. So why not build with wood instead of concrete and steel?
The usual reason is strength, but at Cambridge University has what he thinks is the answer- cross-laminated timber. It's strong enough to build a skyscraper and replaces lots of that carbon from conventional building.
What our expert says
We invited FRGS, a Research Fellow in Energy, Climate and Health at the University College London Energy Institute, to offer some observations on the potential of cross-laminated timber beams, and the use of timber in buildings generally. His points take some of the themes of the programme a step further, and some relevant links are offered below:
When focusing on buildings, it’s important to recognise that when you take a ‘whole life-cycle’ approach to a building’s greenhouse gas (GHG) emissions, it becomes clear that , principally in the form of emissions arising from heating and cooling. Therefore, a focus on reducing construction emissions is most relevant in scenarios where the energy supplied to buildings is already low carbon.
In terms of replacing concrete and steel in construction, it is unlikely that cross-laminated timber (CLT) would be viable for the majority of built environment uses. , which investigates the life cycle carbon emissions and carbon storage capacity of a CLT multi-storey residential building, makes clear that only the building superstructure can be replaced by CLT. The fact that emissions savings are also very , adds further uncertainty.
Globally, the fastest growing urban environments are in China, India and sub-Saharan Africa. Here, there may be more scope for CLT. However, the increased demand on the lumber industry must also be considered. Within this broad field there is also which hold the potential act as carbon sinks. The importance of placing these technological advances within a wider policy context must be considered.
With this in mind, it's worth reading the conclusions of the which emphasises the importance of building codes/regulations."
Further reading
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Ibn-Mohammed, T. et al. (2013), , Energy and Buildings 66, pp. 232-245
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Darby, H.J., Elmualim, A.A. and Kelly, F. (2013) In Proceedings of the Sustainable Building Conference, Munich, Germany
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Ramage, M.H. et al. (2017) Renewable and Sustainable Energy Reviews 68, pp. 333-359
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Global Alliance for Buildings and Construction, International Energy Agency and the United Nations Environment Programme (2019) (pdf)
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Rathi, A. (2017),, Quartz
About the series
39 ways to save the world is a new radio series by BBC Radio 4 developed in partnership with the Society and broadcast in 2021. It showcases 39 ideas to relieve the stress that climate change is placing on the Earth. In each 15 minute episode Tom Heap and Dr Tamsin Edwards meet the people behind a fresh and fascinating idea to cut the carbon.
Over the course of 2011, the Society will be producing events and digital content to accompany the series.
Episode 2: Wood for good
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Replacement of steel and concrete with these timber-based technologies looks to be most impactful in low to medium-density residential contexts. Moreover, in countries such as the UK, that have ‘mature’ built environments, the vast majority of buildings that will be standing in 2050 already exist. The focus in terms of slashing emissions from the building stock should be on the improvement of energy efficiency in buildings via retrofit and the decarbonisation of the energy supply.