22 May 2020

Building with wood in a climate emergency

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“Without increased and urgent mitigation ambition in the coming years, leading to a sharp decline in greenhouse gas emissions by 2030, global warming will surpass 1.5°C in the following decades, leading to irreversible loss of the most fragile ecosystems, and crisis after crisis for the most vulnerable people and societies.”


The above quotation is taken from the special report Global Warming of 1.5°C, published by the Intergovernmental Panel on Climate Change (IPCC) in 2018. The report makes the point that, while keeping global temperatures below 1.5°C above pre-industrial levels is technically feasible, it would take unprecedented transformation of all aspects of our society.


This report made headline news in October 2018, but only for one day. It was only after the report was ‘translated’ into plain English, by the then unknown teenage Swedish climate activist Greta Thunberg, that the world started to take note. The UK Government, devolved administrations and many local authorities have now declared a climate emergency.


Now that climate change denial is finally off the table, there is the political space for all sectors of society to focus on the rapid mobilisation of solutions. This is where plantation forestry and the use of timber in construction come to the fore.


Mitigating carbon emissions with timber

Given that one-third of global carbon emissions is related to deforestation (the other two-thirds due to the release of carbon dioxide from fossil fuels), it is no surprise that one of the solutions to counteract climate change is to plant trees. Trees are nature’s carbon capture and storage solution.


In fact, photosynthesis is the only proven system for atmospheric carbon removal and storage. A recent report The Global Tree Restoration Potential describes the potential for trees to tackle climate change. Growing trees to lock up carbon is one thing, but if we then use those trees in housing construction, the benefit is increased. Research funded by Woodknowledge Wales indicates that the carbon benefit from afforestation can be doubled over 100 years if we grow and process the timber for the construction market.


Timber, when used in construction, has two main benefits. First, timber products are typically lower embodied carbon (the carbon released in extracting, transporting and manufacturing) than other products and therefore displace high-carbon materials. Steel, cement, plastic and glass are the wonder materials of the past century – but their high embodied carbon means that they are unlikely to be considered so appropriate to the needs of the 21st Century.


‘We’re going to introduce legislation to ban the glass and steel skyscrapers that have contributed so much to global warming. They have no place in our city or on our earth anymore’ – Bill de Blasio, Mayor of New York City (April 2019).


Second, when timber is used in construction, the biogenic carbon creates a store in the built environment. This store can be increased if wood is used not only for the structure but also for insulation, and internal and external joinery. It is the expansion of this store that can double the carbon storage benefit of afforestation.


Policy and regulation

This should make growing trees and using wood in construction a go-to solution. However, as yet there are no government policies in place to make this happen. For example, in Wales there is a forest cover of 15%, which is substantially less than half the European average. In 2018, farming in Wales received a subsidy of £300m and forestry £1m. This goes some way to explaining why there has been no new tree planting in Wales over the past five years. Despite the lack of Government support for forestry, it is still worth more to the Welsh economy than agriculture.


Equally, construction policy does not favour the use of wood over other materials. Approximately 50% of the carbon emissions from housing over a 60-year life is related to the construction products and process (embodied carbon emissions), and is thereby emitted at the time of construction. The other 50% is due to operational carbon emissions – regulated (heating and lighting) and unregulated (appliances).


It is time for construction policy and regulation to tackle the carbon emissions caused by building materials. Targeting net-zero whole-life carbon would encourage Passivhaus levels of energy performance alongside the use of low-carbon materials such as wood. Net zero could be achieved by offsetting remaining emissions through funding tree planting to create a virtuous circle.


This is easy to say (or write), but making it happen is something else. The IPCC describes the need for unprecedented transformation and climate emergency declarations have been made by the majority of UK Local Authorities, both the Welsh and Scottish Governments and the UK Parliament. But there are lots of barriers to change. A few of those across Wales are shown below.


  • Resistance to land-use change resulting in, for example, continuation of environmentally degrading and sub-economic activity such as grazing, or favouring a nostalgic backward-looking preference for ‘native’ tree species rather than creating resilient and productive plantation forestry. Each one of us in the UK is responsible for the consumption of approximately 1m3 of timber per year and yet the UK produces timber at a rate of only 0.2m3/year per capita. The UK is already the second largest importer of timber in the world after China and global demand is set to at least treble by 2050.
  • Building policy and regulations continue to be materially agnostic despite steel and cement accounting for 50% of the UK’s industrial carbon emissions. When it comes to energy, policy correctly favours renewables over fossil fuels.
  • Carbon-illiterate planning authorities want to see traditional vernacular and car-dominated housing developments.
  • Procurement rules don’t allow for the nurturing of new low-carbon supply chains.


Action in Wales

Although starting from a low base in Wales, change is afoot:

  • The Welsh Government has embraced the radical plan (Zero Carbon Homes – Actions to Integrate Welsh Forest Industries with Modern Methods of Construction) to transform the timber construction supply chain and turn Wales into a high-value forest nation.
  • Industrial and economic policy is increasingly targeting foundational economic growth, which means a focus on not just the shiny and new, but on the basic services, such as housing and its supply chain.


It is these foundational economic activities that have the biggest impact on the quality of people’s lives, if not on overall GDP growth.


Local Authorities are also starting to step up. Powys County Council has:

  • Approved a Wood Encouragement Policy, which commits to building with timber and to using the local timber supply chains.
  • Commissioned Woodknowledge Wales and consortium partners, including TRADA, Cardiff Met University and Coed Cymru to deliver the Home-Grown Homes Project – an EU- and Welsh Government-funded research project to explore and recommend actions to overcome barriers to the transformation of the Welsh timber construction supply chain (www.hgh.cymru).


In terms of Woodknowledge Wales membership, an increasing number of its housing association members are committing to building with wood and seeking to support the development of local timber supply chains. This is helping to stimulate activity in the SME-dominated timber supply chains and, over time, this can be expected to lead to the creation of meaningful additional employment, particularly in rural areas.


On the global scale, these actions are of course small. But growing trees and building with wood will certainly help the UK Government meet its legally binding carbon targets and demonstrates global leadership in the fight against climate change.



This is an extract from the Timber 2020 Industry Yearbook. Download the full article, including supporting images, references and further reading, here 


Article written by Gary Newman, Chief Executive, Woodknowledge Wales.