Two thousand percent: that’s the common margin of error when predicting the carbon footprint of infrastructure projects. The huge variance stems from a lack of standardisation in the way infrastructure carbon emissions are measured.
The carbon data problem is highlighted in a new report from the Net Zero Infrastructure Industry Coalition, ‘Is our carbon wallet empty?’, examining the embodied carbon of the UK’s £600bn construction pipeline to 2030. Mott MacDonald is a founding member of the coalition, working with clients and industry partners to take practical steps towards the UK’s goal of net-zero by 2050.
Every project built will result in construction-related and operational carbon emissions, all eating into the UK’s ‘carbon budget’ – the maximum net quantity of carbon we are legally permitted to emit in the next three decades. We wanted to establish the cumulative impact of all those planned infrastructure projects, yet with margins of error as high as 2000%, we are in real danger of underestimating our emissions trajectory and blowing the UK’s carbon budget. Our investigation revealed the scale of the carbon data problem:
Quite simply, accurate data does not exist for the majority of projects in the infrastructure pipeline. We were able to gather accurate data for just 9% of projects, while another two thirds was estimated with the help of data drawn from sources such as Moata Carbon Portal, our own BIM-enabled carbon calculator, which has been used on numerous major projects.
Why the 91% gap? Data has either not been gathered, or nobody ‘owns’ data and will take responsibility for using it or sharing it, or the data is confidential. In some cases, data formatting makes it impossible to use – for example it can’t be converted from carbon per kilometre to carbon per pound spent. Altogether, ‘absent data’ makes it impossible to fully appraise the carbon emissions trajectory for UK infrastructure.
Lack of standardisation
Carbon data for different projects proved hard to compare because different scopes for assessment were used and methodologies weren’t transparent. For most of the projects we analysed, it was impossible to split data into material types. This obscured the contribution of each material type to overall emissions, and where reduction efforts should be directed. Based on construction industry averages over the last decade, we assumed that steel would account for approximately 40% of the pipeline’s capital carbon, while concrete/cement would account for 20%. More refined data would reveal how these proportions will change over the coming years.
Four steps to quality carbon data
The construction industry urgently needs to address these issues by creating a standardised, industry-wide approach to measuring and reporting carbon. Our report made four key recommendations:
1. Measure consistently
The industry must create and use a standard set of carbon emissions factors for all materials and products. These emissions factors must be universally accepted, and continuously reviewed and updated. The emissions factors should be integrated into design tools. Benchmarking sponsored by governments and investors should be used to identify best practice, inform decision making and drive down emissions.
2. Create a carbon planning framework aligned with net-zero
The government must incorporate carbon accounting into the national planning policy framework (NPPF) to ensure net-zero is brought into all areas of national policy. Asset owners should apply greater scrutiny of the carbon impacts of their infrastructure, aiming for net-zero. Carbon data must be available for environmental impact assessments (EIAs) which measure emissions as a proxy for the climate impact of projects.
3. Set clear sector spending limits within the UK carbon budget
Across all sectors of the economy, the government needs to make clear the absolute limits of allowable carbon emissions, sector by sector. And those limits need to be translated to individual companies and projects. We then need to measure performance across the infrastructure industry, with each organisation taking responsibility for its share of the collective budget – savings and over-spend. This requires collaboration across the industry to define the long-term role of the UK’s infrastructure as an enabler of a net-zero economy. We also need better processes for selecting future projects which define outcomes, evaluate performance and identify shortfalls.
4. Design for net-zero by default
All new assets should be designed to be net-zero over their lifecycle, with plans for offsetting any capital or operational emissions developed in tandem with engineering designs, prior to planning and tender.
Implementing these recommendations will enable all sectors to ‘speak the same language’ when talking about emissions. This will lead to accurate and easily comparable data which will reveal the true trajectory of the UK’s emissions and ultimately help the industry to better manage and drive down carbon.