Let’s start at the very beginning

Mimi Zimmer explains that reducing whole life carbon starts with integrating carbon into decision making before the scope is decided.

Right in the middle of the newly updated carbon management specification for infrastructure and buildings, PAS 2080, is a new and important clause. Clause 6 calls on users to manage carbon from a much earlier point in the project cycle than has previously been the norm, and requires them to continue managing carbon as the project progresses through different work stages.

Carbon management is an evolving practice. Until now, carbon reduction efforts have often been focused on the design phase, starting with carbon benchmarking and iterative carbon lifecycle assessments to find the lowest carbon option. But starting at project inception enables carbon to be considered more holistically.

Clause 6 recognises that assets are connected into networks and systems, and that new projects should enable systemic decarbonisation. It encourages users to think about systemic decarbonisation needs and impacts. It recognises that considering the wider system may reduce the requirement for new construction, or remove it altogether. It calls attention to whole life carbon and the potential for trade-offs between capital, operational, and user emissions: higher capital carbon solutions may be right if they enable much greater operational and user carbon reductions; and low capital carbon solutions may not be right if they inhibit operational or user carbon reductions.

Sub-clause 6.1.1 asks value chain members to identify the networks and systems that a planned project interacts with. They must assess their level of control and influence at different stages of work and identify where collaboration with other stakeholders could enable whole life carbon reductions.

Sub-clause 6.1.2 sets out the actions each value chain members must take, at every work stage, to manage carbon. The intent is that every organisation integrates those actions into its internal processes, and that there is consistency between all organisations.

The guidance document to PAS 2080 contains diverse scenarios illustrating decarbonisation challenges and how to approach them. One considers design and construction of a railway tunnel. A small diameter tunnel requires less excavation and consumes less materials than a larger bore tunnel, and its capital carbon emissions are therefore lower. But as trains run through tunnels they must overcome air resistance, which is greater in small diameter tunnels: With little space between the train and tunnel walls, air is pushed forward – the piston effect – requiring more traction power. A larger diameter tunnel allows air to flow around the train, using less traction power. The guidance document reveals that, in this scenario, a 9.75m diameter tunnel will achieve lower whole life emissions than an 8.75m diameter tunnel.

It is crucial to recognise and engage all those with influence from the very start of every project – at the investment decision-making stage.

Mimi Zimmer

Senior carbon management consultant

Such analysis can only be undertaken if the whole value chain is engaged in decision-making. There will be many cases where a member of the value chain does not have control but their knowledge can transform overall carbon performance: their influence is essential.

It is crucial to recognise and engage all those with influence from the very start of every project – at the investment decision-making stage. It is the only way to avoid opportunities being missed.

Our carbon modelling solution, Moata Carbon Portal, is aligned with PAS 2080 and can be used to support the specification's carbon management process. It has been developed for options development and assessment during the early stages of project development. It can be used to quickly and accurately identify capital and operational carbon hot spots. Using Moata Carbon Portal is nine times faster than traditional modelling techniques.

Carbon Portal has been designed for use by anyone involved in infrastructure, not just carbon specialists. Its accessibility democratises low carbon design. It informs decision-making in a way that is transparent and easy to understand.

At the heart of Carbon Portal is the infrastructure industry’s most comprehensive database of carbon emission factors for materials, products and processes.

Users worldwide employ Moata Carbon Portal at various levels of detail – from broad overview to highly granular. Carbon data can be broken down by lifecycle stage, material type and phase of work. This enables influence, challenge and innovation across project teams.