National Highways director of environmental stability Stephen Elderkin (pictured) says supporting net zero construction and committing to low carbon materials is key to this decarbonisation.
As the operator of England’s strategic road network (SRN), we are responsible for keeping our network ready for the future. We know most journeys will still be made by road in 2050 when the UK has to reach net zero.
So it is crucial that we lead the drive to decarbonise road transport. Fortunately, our role also means we have significant influence over the transport and construction sectors to help accelerate this transition.
In our Net Zero Highways Plan, we have set the ambitious target of getting our maintenance and construction activities to net zero by 2040. Two thirds of these emissions are embedded in the materials we use, particularly in the production of steel, asphalt, and concrete.
As one of the largest consumers of these materials, we have a vital role to play in influencing change and innovation. That’s why we are taking the bold step of introducing maximum carbon intensity levels for three of our key construction materials, steel, concrete, and asphalt, between now and 2040.
These levels aim to eliminate the most carbon intensive products and signal to the industry our demand for the production of materials with lower and lower carbon levels, while still meeting technical specifications. This matters. Concrete accounts for 8% of global carbon emissions, and steel accounts for 7%.
Why do we need to consider carbon intensity?
Net zero, as defined by the internationally recognised Science Based Targets Initiative (SBTI) is challenging to achieve – you have to reduce emissions within your value chain by at least 90% compared to your baseline year, with the option to offset only up to a maximum of 10% of your baseline emissions with high-quality carbon removals. For our construction and maintenance emissions, that means reducing them by around half a million tonnes of CO2 a year.
With two thirds of these emissions arising from the materials we use, our net zero commitment is going to be out of reach unless we can substantially decarbonise their production. After all, we know that we will still be using a lot of these materials in 2040. There are several challenges to overcome for these materials:
Their production is energy intensive. Much of the energy is currently supplied by fossil fuels.
Emissions are not just released from the burning of fossil fuels: for example, creating clinker from limestone, a step in the production of cement, unavoidably releases carbon dioxide as part of the chemical process.
Investments in cleaner production processes are large and production plants are long lived. Investors need confidence that there is demand for cleaner materials, even if they are a bit more expensive.
Setting our stall out
The carbon intensity of a material is the measure of how much carbon dioxide and other greenhouse gases are emitted per unit of production. In this case, it would be how many kilograms of CO2e (carbon dioxide equivalent) are emitted per tonne of asphalt and steel, and per cubic metre of concrete. Setting a maximum carbon intensity means putting a cap on how much CO2e can be emitted per unit of material produced.
These maximum carbon intensity requirements will be implemented in future contracts and provide a signal to material suppliers that we will not be a market for materials produced in the dirtiest production facilities.
The maximum carbon intensity levels will tighten over time in line with our roadmaps for decarbonisation. Embedding these carbon intensity requirements into future contracts is making that statement a reality. These will help set us apart as a net zero carbon leader and help drive the supply chain in the right direction.
Working together to change our sector
It is critical that we work together with other infrastructure clients. Success is driving the investment needed in production facilities and thereby ensuring a plentiful supply of low carbon materials. Big as we are, we are not big enough to move the entire sector, but by joining with others we can move the market.
Excitingly, other infrastructure clients are adopting the key elements of our approach. ConstructZero, a workstream of the Construction Leadership Council guided by Matt Palmer (Lower Thames Crossing executive director), has set out five asks that infrastructure clients should be making. Five infrastructure clients have signed up already, with the expectation that a further five will have signed up by the end of the year. More will follow.
We will be among the leading five, as we had already signed up to the contracting for low carbon and diesel free sites by 2030 elements as well as implementing PAS 2080. Now we have the agreement to require ever lower carbon intensity for concrete and steel. We are also adding a sixth with requirements for asphalt given that this material accounts for about a sixth of our construction emissions.
By leading this sector to invest in a lower carbon future, we will make a significant contribution to mitigating climate change.
