The production of materials used to create the built environment generate a significant amount of emissions, whether its digging aggregates out of quarries, cutting trees in forests, or producing steel in blast furnaces. Each of these processes takes energy to operate, and that energy doesn’t always come from 100 per cent renewable sources.
As Canada pushes towards its net zero targets in the decades ahead, how does the production of materials for the built environment find ways to reduce its carbon footprint?
Finding ways to reduce the volume of building materials used can be a quick win for emissions reductions in building materials, especially materials generated from the refurbishment or removal of an asset. According to Will Nash, WSP in Canada’s Team Lead for Materials Performance in B.C.: “The three Rs are applicable here: recycling materials is good, reusing materials (or components) is better, and reducing material use is best. Even if we decarbonize our materials completely, we are still facing the collapse in biodiversity caused by excessive consumption, so the number one goal should be to use what we already have.”
As mentioned earlier, producing building materials takes energy, and that energy isn’t always clean. Switching to electric vehicles powered by clean, renewable energy resources would create immediate emissions reductions. In the past five years, there have been significant developments in electrification of key machinery used in industries such as aggregate production and timber harvesting and processing, as equipment manufacturers develop hybrid and electric heavy equipment.
Increased integration of low embodied carbon materials will help reduce emissions, but must be considered early in the design phase of the project. However, it’s also important to recognize that mass timber materials, the use of which are on the rise in Canada, need to come from sustainably-sourced plantations versus old-growth forests, as Nash cautions that “old growth logging is the largest emitter of carbon in Canada, not only due to burning of timber, but the loss of soil carbon stores.”
Next Generation Solution
As new technologies continue to develop from the bench scale to the commercial scale, the medium-term outlook for reducing emissions in building materials is promising.
Solutions for reducing the embodied carbon of concrete, using alkali activated materials and other alternatives, are well into development. In Germany and Sweden, hydrogen-reduced steel is being piloted and should eventually lead for zero emissions steel. The Elysis process, being piloted in Quebec, is producing zero emissions aluminum. The development of low emissions float glass by Canadian company Wanipigow Glass is expected to reach production sometime in 2022. There is also the prospect of building using short-rotation crops such as bamboo and hemp fibres, which can store carbon for as long as the buildings are maintained.
“There is exciting research about using microbial grown cements, artificial photosynthesis for organic chemistry, genetically engineered crops to produce high value fibers like spider silk, and producing carbon nanotubes from atmospheric CO2,” said Nash, mentioning additional research that could lead to low carbon solutions for future building materials.
In addition to the savings that can be found through materials harvesting and production, emissions reductions will also be found through greater planning of how materials will be used at the end of built asset’s life cycle. Planning for the three R’s for all materials used, at the beginning of the design process, can reduce the overall carbon emissions of the built environment.
Making the necessary adjustments to reduce emissions towards net zero in materials production will not be a simple feat, as there as difficult obstacles to overcome in the process.
“Most of the challenges are to do with bureaucracy, allowing flexibility in engineering standards, and upsetting the status quo. Lots of incumbent producers have invested massively into their production pipeline. Resource extraction and transportation emissions are not entirely within the industry’s control, and manufacturers need to demand more sustainable supply chains to improve their products.”
WSP Group Lead, Materials Performance and Corrosion Control
Greenwashing also remains a risk, as companies may overstate the emissions reductions they are achieving. There is a risk that this could happen, both in the production and extraction of materials.
In the rush to create greener materials for the built environment, there is also the risk that products could be brought to market before they have a proven track record. This has occurred before, polybutylene water pipes as an example, where unproven products have been rushed to market but don’t meet performance requirements. Designers need confidence in these lower emissions products before they will be widely adopted.
It will take changes from governments at all levels to meet the demands of reducing carbon emissions in materials processing and production. It will also mean that companies already entrenched in these industries will have to make significant adjustments to their operations, something that may require legislation to enforce.
With low carbon grids already in place British Columbia, Manitoba, Quebec and Ontario, Canada is poised to be a global leader in the production of low carbon materials.
Our WSP in Canada team understands that we too have a role to play in helping the industry make the necessary adjustments.
“As engineers, we can take a leading role by developing performance-based specifications that target low embodied carbon, and using novel materials in non-critical areas so that long term performance data can be gained to improve performance and confidence.”
To learn more about how WSP in Canada can help reduce carbon emissions in building materials, visit our Net Zero Emissions Pathways page or reach out to Will Nash.