Report: Carbon Cost in Infrastructure: the Key to the Climate Crisis?

Just how large an effect does infrastructure construction, operation and use have on our climate today? In the report, Carbon Cost in Infrastructure: The Key to the Climate Crisis? experts explore ways in which we can minimise both carbon emissions and cost associated with infrastructure development.

Infrastructure, an emissions giant

In the UK today the construction, operation and maintenance of infrastructure assets results in approximately 16% of total carbon emissions. This figure rises to 53% when the use of infrastructure is incorporated, a proportion that is expected to increase to over 90% in the coming decades. These figures are not unique to the UK, they are mirrored internationally.

The carbon cost relationship

There is a strong relationship between carbon and cost in infrastructure. Carbon is a proxy for energy, the use of natural resources and quantities of materials; therefore, reducing carbon usually reduces cost.

“Reduce carbon, reduce cost” was a key message from the 2013 UK Treasury Infrastructure Carbon Review, it was a message that was intended to reassure stakeholders and drive carbon reduction. However, “Reduce carbon, reduce cost” is really only the beginning. The alignment between carbon and cost is clear, with the greatest potential for reduction existing at the earliest project stages.

Knowing that there is a relationship between carbon and cost is important, but to practically apply this knowledge requires a deeper level of understanding.

Carbon Cost Intensity (CCI) is a measure of the carbon emitted for each unit of cost spent, e.g. kilograms of carbon dioxide equivalent per euro (kgCO2e/€). It can be used to prioritise carbon reduction measures within a fixed budget and identify the most cost-effective carbon reduction options: the best carbon ‘bang for your buck’. CCI can be applied at three general levels: granular, mid-range and project. It is a powerful metric for prioritising project options in carbon cost terms, including alternative routes, materials or construction techniques.

The tipping point

When the goal is net zero emissions, the carbon cost tipping point is a problem.

Through efficient design – reducing material quantities and minimising construction operations, both carbon and cost in infrastructure can usually both be reduced to a certain point. However, lower carbon solutions exist that currently cost more than traditional options.

The point at which costs start to increase to reduce carbon further can be defined as the ‘carbon cost tipping point’. When the goal is net zero emissions, the carbon cost tipping point is a problem.

Naturally however, as the market for low carbon materials and construction techniques evolves, the carbon cost tipping point will shift, with higher carbon solutions becoming more expensive. Until then, it is a financial barrier to net zero carbon.

Values are for illustrative purposes.

Tipping point, today or tomorrow?

…is it better to emit carbon now from construction projects that will create carbon savings in the long term? Or is it better to emit less…

Tipping points in the context of whole life carbon assessments raise an issue that is rarely discussed: is it better to emit carbon now from construction projects that will create carbon savings in the long term? Or is it better to emit less carbon now by maintaining our existing infrastructure, given the urgency of the climate crisis and the requirement to drastically reduce carbon emissions? The answer to these questions lies at a strategic level, with carbon cost management at its core.

Beyond the tipping point

We cannot rely on carbon reduction to naturally occur through traditional design. We must start to consider our options beyond the tipping point.

As more governments and local authorities understand the contribution of infrastructure to their total carbon emissions, and awareness spreads that achieving net zero emissions will require investment, what incentives exist to select options beyond the tipping point?

Incentives: carbon taxation

One mechanism is carbon taxation. A recent report on carbon pricing by the Grantham Research Institute on Climate Change and the London School of Economics included recommendations for proportionate carbon taxation across all key sectors.

Emissions associated with infrastructure construction have been largely overlooked to date, in favour of operational emission targets. Given that the relative significance of construction emissions is set to increase in coming decades, any carbon tax introduced to steer a nation towards net zero emissions must also incorporate embodied carbon.

Limits to carbon reduction

Offsetting should be regarded as a last resort, not a licence to emit.

Carbon emissions may be reduced as far as practicable, but if we continue to build new infrastructure, we will continue to emit carbon. With national net zero targets, how do we deal with these remaining emissions?

The IPCC states that negative emissions technology will be required, although this technology is still emerging and would need to be deployed at a national scale, demanding unprecedented energy resources. A natural form of atmospheric carbon dioxide removal exists in the form of trees. However, trees are slow to absorb carbon and are unlikely to be sufficient to balance residual infrastructure emissions. Many carbon offsetting schemes involve tree planting, but offsetting should be regarded as a last resort, not a licence to emit.

The relative costs of carbon taxation and carbon reduction need to be closely monitored to identify the most economical and meaningful options beyond the tipping point.

Making it happen

…the carbon management process will have limited success if the costs of reduction options are not also considered.

Recently, there has been a gradual shift from carbon accounting to carbon management. Carbon accounting is a passive approach with little bearing on the design process. We will not achieve national net zero carbon targets through carbon accounting alone. Carbon management is an active process where options for reduction are considered and integrated into the design process. However, even the carbon management process will have limited success if the costs of reduction options are not also considered.

The next level is carbon cost management. This process involves all the aspects of good carbon management, but it also includes costing of all carbon reduction options.

Carbon cost management should be applied at the route selection stage. Digital techniques now exist to calculate infrastructure carbon emissions at the planning stage.

Contractual carbon reduction: a necessary measure

If carbon reduction in infrastructure was purely voluntary, we would be unlikely to prevent climate change.

We need integrated and collaborative solutions throughout the supply chain, achieved through procurement processes and national legislation. We are now seeing the creation of tendering mechanisms which demand carbon reduction, encourage innovation and ensure a carbon focus is maintained from project start to finish.

Urgently accelerating change

Given the urgency of our situation and the knowledge that carbon cost management is critical in preventing climate change, we must immediately accelerate the work in this field.

Although cost management is well understood, carbon remains a relatively abstract concept to many, including stakeholders with significant influence in its reduction. To rapidly deploy carbon cost management in infrastructure, a combination of digitalisation and education is required.