One of the key aims of the new UK Concrete Sustainable Construction Framework is to protect our natural environment. Our goal is to develop solutions for a regenerative built environment, incorporate natural capital in decision making and deliver wider ecosystem benefits such as biodiversity net gain. The Framework sets out the need to conserve and enhance biodiversity at extraction and production sites by building partnerships and celebrating the excellent work of the UK minerals supply chain. To this end, the Framework adopts the MPA Biodiversity Strategy which aims to protect and enhance biodiversity and deliver net gain wherever possible.
This position paper will explore how concrete, traditionally seen as a costly material from an environmental perspective, can be viewed alternatively as one that supports biodiversity in the context of the UK’s production methods and quarries.
What is embodied biodiversity
Embodied biodiversity is a relatively new concept looking at the total impact of materials and their lifecycle on ecosystems and wildlife. The concept of embodied biodiversity is analogous to that of embodied carbon which goes beyond how the material is used and includes how it is sourced, produced, manufactured and transported.
Embodied Biodiversity in Concrete
Concrete is the most widely used material in construction, and it is essential to our urban landscapes and infrastructure. Its environmental impacts are well known in terms of carbon emissions, but a less explored theme is its relationship with biodiversity.
Concrete is an extremely versatile material which can be designed to support biodiversity through the creation of new habitat where the hard and soft landscape meet and by incorporating features like raingardens, green roofs and walls, animal habitats and many others into urban environments.
Embodied biodiversity is the sum total of a materials effects on biodiversity over it’s entire lifecycle, whether direct or indirect. For concrete, this includes raw material extraction, production, transportation, lifetime use, and end of life. Concrete can play a positive role in supporting nature and biodiversity through considered material sourcing, design and restoration of quarries.
The sensitive management and restoration of quarries from which the aggregates and limestone used in concrete manufacture are extracted, can and does deliver substantial net gains in biodiversity.
Challenges in measuring and reporting embodied biodiversity
Despite the potential benefits, the greatest challenge for embodied biodiversity is how difficult it is to measure and report on. Carbon emissions are able to be quantified more easily as there is a consensus around the best way to do this already, however biodiversity is inherently more complex. It spans habitats, ecosystem fragmentation, multiple species etc, all of which are incredibly difficult to capture in a single metric.
- No consistent measurement - Biodiversity impacts are difficult to quantify for different parts of the supply chain and lifecycle of concrete. Every quarry, production and construction site is different with a unique set of species and ecosystems, making a one size fits all approach impractical. There are however well-established methods and standards for assessing ecological impacts and this is required for every planning application for development. It is important to stress that all quarries will have a restoration scheme as part of their planning permission.
- Time – Biodiversity is ever changing, and it’s impacts generally happen over a long period of time. These temporal changes are considered in ecological assessments and EIA, and in the [name]Metric. Indeed, methodologies for measuring impacts of quarrying and other development is well-established but measuring biodiversity impacts at different stages of the lifecycle of any product is more challenging.
- Inconsistent standards – Reporting practices across products and materials differ. This lack of a standardised monitoring and reporting framework hinders efforts to assess and report on impacts.
The challenge for the UK concrete industry is to move to a more unified approach in recording, reporting and implementing embodied biodiversity taking into account local conditions and a long-term view. Development of any other metrics of measurement of biodiversity should take into account existing methodologies in place for the supply chain for concrete
UK production and local material sourcing
In the UK, the planning system requires that the ecological impact of development to be assessed, mitigated and compensated for, whether this is for minerals reserves in quarries, or development in which concrete will be used including housing, commercial and infrastructure,
In England, new development, including quarries (from February 2024) must conform to Biodiversity Net Gain (BNG) policies which require developers to ensure that their projects lead to a measurable improvement in biodiversity. The MPA also requires that their members commit to high standards of environmental stewardship which include biodiversity management.
Unlike many other construction materials, the UK concrete industry sources most of its raw materials locally. UK production relies mostly on quarries supplying aggregates such as limestone, gravel and sand. This can have a significant impact on local biodiversity with habitat losses and gains, changes to hydrology and soil degradation. All of these issues are considered in the planning process, including through EIA, and also in environmental permitting of operations. So, whilst there is a benefit in reducing transport related emissions there may be impacts, positive and negative, on local wildlife.
Away from extraction sites, the manufacture of concrete and cement in the UK is also well regulated with strict environmental and procedural processes in place. These include controls related to air quality, water use, and health and safety. Most concrete manufacturing plants are located in industrial areas where the impact on local residents, biodiversity and wildlife tends to be minimal but there are often plans for enhancement and engagement with local stakeholder groups.
Delivering BNG and Restoration
UK quarries have a strong track record of restoring biodiversity post extraction. Many quarries are in areas of high ecological value and operators are required to minimise impacts and restore habitats during and post extraction. This restoration often includes the creation of further new habitats such as wetlands, woodlands or grasslands providing havens for wildlife. MPA members have created at least 8,000 hectares of UK priority habitats to date with at least a further 11,00 hectares committed to in approved restorations schemes.
There are several UK quarries that have been recognised for their outstanding efforts such as the Ibsley quarry in Hampshire which has become designated as a site of special scientific interest. There are in fact more than 700 of the UK’s sites of special scientific interest which are in former quarry sites, delivering multiple natural capital and ecosystem service benefits. This shows what can be accomplished with careful strategy and planning.