Ken Donald, PE, ENV SP, Senior Project Engineer & Carbon Reduction Lead, VHB
Climate change due to the release of excess greenhouse gases is a topic that is rapidly changing the world with its very apparent impacts, and with how people are approaching their daily lives, both personally and professionally. More and more companies are including sustainability in their products, projects and long-term corporate approach with net zero goals. Civil Engineering projects provide necessary services to the public, but the reality is, due to the current methods, materials, management, policies and programs, massive amounts of carbon, both embodied and from operations, are byproducts of the work we do. In fact, the steel and concrete industries each account for approximately 8% of the world’s CO2 emission. To change to a net zero and sustainable economy, every new and rehabilitated infrastructure element must contribute toward this critical transition. We have a unique opportunity in front of us to change how we approach and deliver our projects to mitigate our overall impact now and into the future. We can and must do this by working together because this is a challenge that cannot be solved by one person, one company or even one industry.
I’ve often heard the civil engineering industry described as having the agility of a canoe when it comes to change. As with all fundamental change to our industry, reducing the carbon emissions of our projects, will take time, resources and constant learning from every stakeholder, but it can be done, and it must be done. We can no longer hide behind the idea that sustainability adds prohibitive cost to projects or that our clients do not want it. The reality is much the opposite. The industries we rely on so heavily in steel and concrete have already made massive strides in reducing their emissions. A growing number of states have passed Climate legislation, including Action Plans, requirements for lower carbon electricity, and net zero goals.
Massachusetts passed its Global Warming Solutions Act in 2008 and has increased its carbon reduction and climate goals many times since. One section of the newest climate law Governor Healy signed in November 2024, establishes an Embodied Carbon Intergovernmental Coordinating Council. It requires that The Division of Capital Asset Management and Maintenance (DCAMM) and the Executive Office of Energy and Environmental Affairs (EEA) work together to prepare an embodied carbon reduction plan for state building and transportation projects.
There is much work still to be done, but it is not often recognized the steps that the concrete and steel industries have taken to reduce their impacts already.
The Global Cement and Concrete Association (GCCA) estimates that as of 2020 their industry has achieved more than a 20% reduction in CO2 per ton compared to 1990 levels, through the use of supplementary cementitious materials (SCM) like fly ash and slag. They aim to achieve an additional 20% reduction in cement and 25% reduction in concrete by 2030 compared to the 2020 level. Additionally, they have a path to net zero by 2050 (Photo 1).
The steel industry has also made significant strides by transitioning from blast oxygen furnace (BOF) to electric arc furnace (EAF) production. Nucor estimates that by making this switch they can reduce the amount of CO2 produced per ton of steel from 2.33 tons of CO2 to 0.77 tons of CO2 per (Photo 2).
So where do we go from here and what can you do? There are a growing number of resources available, and several established groups (which are always looking for new members) like SEI SE2050 and ASCE Infrastucture2050, both of which are committed to helping transform the industries with holistic approaches to advancing embodied carbon reduction strategies to more easily work toward net zero. Similarly, the Carbon Leadership Forum, and their Northeast Hub have a vast number of resources available to everyone, no matter where they are on their embodied carbon journey. This is a relatively new aspect to our projects and will undoubtably be refined over the coming years as more research becomes available, but early adoption and inclusion into our work is important. Becoming familiar with where carbon emissions are created throughout the life of an element is the best starting point. And because you can’t manage what you don’t measure, understanding what a Life Cycle Assessment (LCA) is and how to perform one to calculate the carbon footprint of a project is essential if you want to find the carbon hot spots and find ways to reduce the CO2 emitted.