Concrete Steps: How governments can make construction greener

Governments of all levels should set green procurement targets for cement, concrete, and steel.

Tunnel within the Diefenbunker, a cold-war era shelter designed to house the Canadian Government in the event of a nuclear attack. 32,000 cubic yards of concrete and 5,000 tons of steel were used in its construction (Source: Wikimedia Commons).

When people talk about the items in our everyday lives that have the worst environmental impacts, construction materials don’t immediately come to mind. We’re most familiar with the usual suspects: combustion engine cars, beef production, and plastic utensils. We don’t think about the environmental impacts of construction materials because we don’t interact with them to the same extent. If we drove steel plates to work, ate cement burgers for lunch, or drank our smoothies through concrete straws, these materials would get a lot more attention (and not just because it would be seen as weird).

Because of this disconnect, there isn’t as much pressure to look at ways that we can reduce our usage of these materials. This has huge policy implications as cement, concrete, and steel are among the biggest global emitters of greenhouse gases (GHGs).

Direct C02 emissions by industrial sector. Construction materials account for around 20% of global emissions (Source: International Energy Agency).

People are right to be concerned about the role of plastics in construction and daily use because petrochemicals account for around 4% of global GHG emissions. But at over 7% each, it’s clear that cement and steel are much bigger perpetrators.

What makes these materials so dirty?

Some of concrete’s emissions can be attributed to its sheer volume. As the “most widely used man-made material in existence,” it is only natural that concrete would have a significant global carbon footprint. But the majority of its emissions occur during the production of its core ingredients. Raw materials like limestone and clay are crushed and then heated in a kiln to over 1,400 C to create clinker, the main component of cement. This process, known as calcination, accounts for around half all cement production emissions. The next biggest emissions contributor is the fuel used to heat the kilns.

Similarly, steel is energy intensive in its production and emits high GHG quantities during the reduction process. When it comes to determining the carbon footprint of a good or service, the emission levels from construction materials are reflected in the embodied carbon of the final product.

A few green alternatives are emerging in these sectors. For example, the Cement Association of Canada is championing the introduction of Portland-limestone cement, an alternative to regular cement that is expected to reduce emissions by 10%. CarbonCure, a Halifax-based company, is also gaining traction due to its innovative carbon capture approach that injects emitted CO2 back into the concrete products themselves. Although there are some similar green innovations happening in the steel sector, the most promising alternative is to replace fuel-based blast furnaces with electric arc ones.

These innovations can play a huge role in reducing the embodied carbon of construction and infrastructure projects. While materials sectors will likely never be net-zero themselves, lowering their emissions will contribute significantly to national and local climate change strategies.

Despite the advantages of green concrete and steel, a few obstacles remain. On the supply side, these alternatives can be very expensive and they lack the capacity for larger scale production. And while there’s a growing interest in lower-emission materials from the consumption side, this demand hasn’t reached a level that will enable an industry-wide market transition just yet. Fortunately, governments can use their purchasing power to nudge suppliers towards less carbon-intensive practices.

Green Procurement: Power to the people

Governments spend a lot of money on buildings, construction, and infrastructure. By my estimation, the federal government alone spends over $3.5 billion towards the construction and maintenance of assets like government buildings, highways, and bridges. The bar chart below shows how these categories (in orange) compare to other big areas of expenditure like IT and vehicles (in blue).

Average annual spending by Public Services and Procurement Canada (PSPC) on contracts, from April 2009 to March 2021 ($ millions). All data was obtained from the Open Government Portal, but recoded into my procurement dashboard.

It isn’t just the feds who spend a lot on these materials — more than half of all government expenditure on construction comes from the provinces, territories, and municipalities. The table below shows estimates of jurisdictional spending on major construction commodities.

Government expenditure by jurisdiction on major construction materials, from Statistic Canada’s 2017 Supply and Use Tables. For a detailed breakdown by material, click here.

In Canada, nearly 16% of construction material spending comes from taxpayer funded institutions. That figure is even higher in the markets for steel (25.4%) and cement and concrete (28.9%). If governments work together to establish greener standards for construction supply chains, it can be possible guide material suppliers to cleaner alternatives.

Some jurisdictions are beginning to recognize the power of procurement in ensuring greener construction projects. For example, the Government of Canada aims to reduce embodied carbon in construction projects by 30% in 2025 through procurement commitments that will encourage market transformation. Several provinces have net-zero building targets, and municipalities like Vancouver have committed to a 40% reduction in embodied emissions by 2030.

Outside Canada, policymakers are exploring the role of green procurement as way to decarbonize heavy industry. The United Nations Industrial Development Office (UNIDO) and the Leadership Group for Energy Transition (LeadIT) recently published a paper on this very topic. This document also serves as the background paper for the International Deep Decarbonization Initiative (IDDI) being supported by Canada. The IDDI hopes to “standardize a life cycle assessment of embodied carbon, set ambitious procurement targets, and establish tools for comparing the environmental impact of industrial products.”

In both local and international settings, Canada is emerging as a leader in using procurement tools to attain net-zero emission targets. By drawing on the potential successes of intergovernmental procurement initiatives, Canada can set a path for local governments and private contractors to follow in reaching net-zero. Green procurement policy won’t solve all of Canada’s climate change problems, but it will reduce embodied carbon levels in construction. If governments collectively demand cleaner alternatives, the market will follow suite.

Disclosure: From January 25 to June 2, I worked on the Green Procurement team at the Centre for Greening Government within the Treasury Board of Canada Secretariat (TBS) where I supported projects such as the IDDI. All government procurement data presented in this piece was obtained publicly through PSPC’s Open Data Portal and through Statistics Canada’s Supply Use Tables.