By Dr. Wil Srubar
If Colorado truly envisions itself to be a bold leader on tackling climate change, our state must have a strategy for decarbonizing concrete. Although concrete is not always top of mind, this critical building block presents a wealth of opportunities for sustainability and business innovation — as well as reducing harmful emissions.
This critical material is the literal foundation of our society; after water, it’s the most widely used substance on Earth. But the production of concrete’s key ingredient, Portland cement (a generic term, not a brand name), generates a staggering 7% of the world’s heat-trapping carbon dioxide — triple the emissions of civil aviation.
The good news is there are solutions to this challenge; even better, some solutions are cost-effective, resilient, and ready to deploy at scale now, creating Colorado jobs while safeguarding our communities for the long-term.
“Low-carbon concrete” uses alternatives to Portland cement, such as slag, ground waste glass, and other pozzolans, or new innovations such as injected carbon dioxide, creating a mix that’s just as strong and durable, while reducing carbon emissions. “Carbon-storing concrete” strategies go a step further by incorporating limestone aggregates and fillers made using carbon dioxide or creating new, biomineralized concrete alternatives that do not contain Portland cement, thereby transforming concrete into a net-carbon sink.
The Buy Clean Colorado Act (https://leg.colorado.gov/bills/HB21-1303) takes a solid first step in the right direction. Thanks to the dedication and drive of State Reps. Tracey Bernett and Barbara McLachlan as well as State Sen. Chris Hansen, this climate legislation was signed into law by Gov. Jared Polis in July 2021 and sets the maximum acceptable global warming potential for materials utilized by the Colorado Department of Transportation and certain public works – including buildings, roads, highways, and bridge construction projects. With as much as 40% of all concrete production going to public sector projects (https://www.globalefficiencyintel.com/scale-of-government-procurement-of-carbonintensive-materials-in-us),
Colorado has an enormous amount of leverage to help encourage adoption of low-carbon and carbon-storing concrete and related policies. It’s called the power of procurement for good reason, after all.
Our state’s leaders have the chance to accelerate this innovation – and set the standard for the rest of the nation. By incentivizing the use of low-carbon and carbon-storing concrete, we can reward and empower businesses, contractors and architects for investing in bold steps toward climate resiliency while at the same time providing the flexibility and adaptability needed to weave this innovation into our infrastructure projects statewide.
This is not going to be a one-size-fits-all plan and there is indeed no silver bullet. Instead, it will require approaches from a variety of angles with many different innovations and companies to help make this bold decarbonization effort a reality. Because of this, we need smart policymaking to ensure all of those critical tools are fully developed and deployed.
With weather extremes also more likely for our state going forward, we can no longer afford to build our roads and infrastructure in the same way now as we did when the interstate system was constructed in the 1950s. Our recent severe and chronic drought and the devastating Marshall Fire are sobering warning signs of the climate conditions and events we now must anticipate in a warming world.
Infrastructure resiliency in the face of more frequent and expensive disasters will be a necessity and we must build to last and in a better way than before – while also protecting critical jobs and spurring economic development opportunities for our state.
Colorado has a rich history of being at the forefront of greentech and innovation. This is one such way that we can lead – not just in rebuilding our infrastructure, but ensuring it stands the test of time and is made to be climate- and extreme-weather resilient from the get-go. Beyond procurement at the state and municipal levels, Colorado lawmakers should explore how to ramp up – with tax credits or other incentives – the private sector’s adoption of technologies and techniques to help decarbonize the cement and concrete industry.
With passage of the bipartisan infrastructure bill, Colorado has an opportunity to invest those federal dollars in our roads and public works for the long-term. And we know our state’s nearly 200,000 miles of paved roads are in need of serious improvement, earning an overall C- score (https://infrastructurereportcard.org/state-item/colorado-infrastructure/) on the American Society of Civil Engineers 2021 report card.
We as Coloradans can certainly do better than mediocre. We must build our roads and infrastructure back better in a more resilient way and with reduced carbon emissions. It’s not mutually exclusive. We can – and must – do both for Colorado to become the nation’s climate leader today and to be better prepared for tomorrow.
Dr. Wil Srubar is an Associate Professor of Architectural Engineering, Engineering and Materials Science, and Engineering at the University of Colorado at Boulder.
