January 24, 2021
The Green reboot of our economy needs to tackle infrastructures’ embodied carbon
Most of us know that when we jump into our cars and scoot off to work carbon emissions are produced. Globally, close to 25% of CO2-emissions come from cars, lorries and trains moving around. However, few are aware of the quantity of carbon emissions that are produced when building tunnels, bridges and railways. These hidden emissions are called ‘embodied carbon emissions’.
Embodied carbon emissions are the emissions produced when materials are manufactured and transported as well as the energy that is used during the construction of infrastructure. In the buildings sector, embodied carbon has been a focus area for some time. We should apply the same type of thinking when we design and build infrastructure.
Reducing the economic fallout from COVID-19 is the highest priority for governments worldwide, and many have targeted investments in infrastructure as an effective way of stimulating the economy. The EU has pledged to invest over €2 billion in 140 key transport projects to jump-start the economy. How we spend that money has a profound impact on our climate. Any decisions made today will have long-term consequences both for the climate and the economy if the embodied carbon and resilience of new and existing infrastructures is not considered.
“Depending on the type of infrastructure, emissions from embodied carbon range from 2-24% equal to many years of operational carbon. Tunnels, tracks and bridges are the main culprits due to the vast amount of materials needed for construction. In Ramboll, we are developing a framework to minimise the carbon embodied in infrastructure”, says Peter Heymann Andersen, Managing Director, Ramboll Transport.
An essential first step is to apply a Life Cycle Assessment (LCA) approach which should be understood as a holistic framework to measure the impact of an infrastructure project across the life cycle of a project. The application of such a methodology ensures attention to both the environmental and climate impact and the circularity of resources that are used.
The biggest carbon and cost impacts come from decisions made early in the design process that can lead to material-efficient design solutions and support the uptake of low carbon materials. Activities that impact embodied carbon must be included in early design considerations.
Materials account for nearly 80% of the total embodied carbon emissions – with just two materials– steel and cement – accounting for over 75% of overall embodied carbon. Reducing material usage and switching to low-carbon materials in the early stage of design can lead to significant reductions in the embodied carbon.
Future infrastructure projects should develop baselines and set targets based on cost and carbon reduction potentials. Many markets are exploring how to standardise an approach for measuring the overall sustainability level, e.g. CEEQUAL and DGNB like you see in the building sector.
If we are to reach our targets in reducing carbon emissions, we need to simultaneously focus on developing low carbon transport systems like rail, bus and cycling. In addition, we need to rapidly increase efforts to tackle embodied carbon emissions from delivering infrastructure and investigate how we can increase the longevity of our infrastructure assets.
“Achieving the targets for reducing carbon emissions is only possible if public procurement is directed towards low-carbon infrastructures. All actors across the value chain, including manufacturers, authorities, contractors and engineers, need to cooperate to ensure a transformation in how we deliver infrastructure in the future. This will have a transformative impact on our infrastructure industry”, says Peter Heymann Andersen.