As significant as the COVID-19 pandemic has been during the first half of 2020, media attention has been drawn away from another global crisis — carbon emissions.
The construction industry has a critical response role to play in the world’s future, according to Erik Solheim, executive director of the United Nations Environment Programme.
“We urgently need to move towards a pollution free planet, to tackle climate change and to drive sustainable development,” writes Solheim in the UN’s 2017 Global Status Report. “We can only do that with decisive action in this sector. Technologically and commercially viable solutions exist, but we need stronger policies and partnerships to scale them up more rapidly.”
“Buildings and construction together account for 36 per cent of global final energy use and 39 per cent of energy-related carbon dioxide (CO2) emissions when upstream power generation is included,” the UN report says. “Progress towards sustainable buildings and construction is advancing, but improvements are still not keeping up with a growing buildings sector and rising demand for energy services. The energy intensity per square metre (m2) of the global buildings sector needs to improve on average by 30 per cent by 2030 (compared to 2015) to be on track to meet global climate ambitions set forth in the Paris Agreement.”
There are three basic elements concerning construction-related carbon emissions addressed in the UN report.
First is building envelope design.
“An urgent focus on building envelope performance and design is needed, including the policy levers and financing tools that enable affordable and sustainable building construction and renovations,” it reads.
This leads to the second element, the use of fossil fuels. According to the UN, fossil fuels were responsible for 82 per cent of total energy consumption in buildings in 2015, including electrical generation.
“From an operational perspective, improved sensors and user controls can enable improved human-building interactions.”
Hidden from view is the third element, Embodied Carbon (EC). Of building and construction’s 39 per cent contribution to global CO2, approximately 11 per cent can be traced embodied emissions associated with new building construction.
Anthony Pak, principal at Priopta, a Life Cycle Assessment (LCA) consultancy, and founder of Embodied Carbon Network (Vancouver), defines EC as, “the life cycle environmental impact associated with construction materials.” He refers to EC’s 11 per cent contribution to global CO2 as the construction industry’s “blind spot,” a result of focus being centred on operational carbon emissions and not on materials and building processes themselves.
EC, as Pak describes it, is a cradle-to-grave concept.
“All those materials have upstream environmental impacts through extraction, manufacturing and transporting, even end-of-life impacts through incineration, land filling, recycling,” he says.
The good news is that the construction industry has started to embrace the issue of EC, as evidenced by its acceptance of the cloud-based, open-access Embodied Carbon in Construction Calculator (EC3).
The EC3 Calculator is the creation of The Carbon Leadership Forum (CLF), an industry-academic alliance focused on reducing the EC in building materials such as concrete, steel, wood, glass, aluminum, insulation, gypsum, carpet and ceiling tiles.
The data-driven EC3 tool, in conjunction with the construction industry’s database of over 16,000 Environmental Product Declarations (EPD), allows architects, engineers, owners, contractors, building material suppliers and policymakers to evaluate EC in project specifications.
It’s been very effective so far. In fact, the alliance estimates that during the EC3’s recent pilot period, carbon emissions were reduced by 30 per cent in participating projects.
According to the CLF, the EC3 “is revolutionizing the review of material or product environmental metrics by creating searchable digital EPD’s and translating all declarations into that form for viewing and analyzing project data.”
Change is imperative.
According to the UN Global Status Report, without more ambitious efforts to address low-carbon and energy-efficient solutions, total CO2 emissions from the global building sector in 2060 will increase by 30 per cent from 2015 levels, with EC’s contribution to that total leaping from one-third to 50 per cent. Those are levels of emissions the world cannot afford.
John Bleasby is a Coldwater, Ont. based freelance writer. Send comments and Inside Innovation column ideas to firstname.lastname@example.org.