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Civil Engineer blog

The Carbon Project: infrastructure and the circular economy 

15 November 2021

A circular economy provides an environment for low carbon design and creates massive opportunities for infrastructure engineers. Changing mindset may be the biggest challenge.

The Carbon Project: infrastructure and the circular economy 

In the UK's infrastructure industries, measures to reduce carbon emissions are too often dismissed on grounds of economic viability.

Despite good intentions, how many designers invest the time and skills needed to offer a low-carbon alternative for every project, knowing that unfamiliar solutions are more likely to be rejected? Will clients agree to a design that is perceived as costly, even if there are environmental benefits?

This kind of reluctance may be understandable, but prioritising short-term gain over long-term success is increasingly out of step with the economics of the future.

Circular economy principles

Economics is inextricably linked with resources. These encompass the natural resources provided by the land, air and water, and the human resources of labour, skill, innovation and knowledge.

The principle of a circular economy, first explored in the 1960s, describes a system in which products and assets are used, repaired, transformed and reused indefinitely: in other words, where the human resources of labour, skill, innovation and knowledge are used to preserve and maintain an initial investment of natural resources (materials), extracted from the ground.

In contrast to recycling, the circular economy aims to be a zero-waste system. It emphasises adaptation and reuse of manufactured goods and assets in the most complete form in which they can continue to be useful - such as London Underground tube trains being repurposed for the Isle of Wight railroad.

It is increasingly seen as a robust and compelling alternative to our linear system of growth and waste, in which natural resources are extracted, used and rapidly discarded in various polluting forms.

Finite resources limit the future of any economy that is based on their extraction. The waste products created by this system - including CO2 emissions - are now significantly damaging our world. In contrast, the circular economy supports a sustainable lifestyle, including new and transformed industries to replace those sectors that currently serve an unsustainable way of life.

Importantly for civil engineers, there are strong synergies between the principles of circular economy and the design, use and reuse of infrastructure in ways necessary for the UK to meet its carbon net zero commitment by 2050 and beyond.

Big enough to make a difference

Completing the picture: How the Circular Economy tackles climate change, commissioned by the Ellen MacArthur Foundation, makes the assessment that only 55% of CO2 emissions can be eliminated through a complete shift to renewable energy sources. The remaining 45% will grow proportionally as global energy supply is decarbonised.

The report examines the carbon impact of materials - steel, concrete, plastic, aluminium - for which CO2 emissions are harder to abate, because the processes used to create them are inherently CO2 producing. A circular economy provides the answer: re-use or replacement with regenerative materials are the far better options.

The circular economy supports and is supported by carbon net zero goals

Designing out waste is not the same as designing out carbon emissions.

However, measures that reduce carbon emissions - building less, adapting more, recycling existing materials and components, using renewable resources wherever possible, providing robust project data and designing for reuse - all support the economic shift from production and waste to regeneration and renewal.

Thus, for civil engineers and their clients, the circular economy provides a framework within which to situate the effort to reduce carbon impact.

Effort is undeniably involved. Not all solutions that reduce carbon emissions make a project more expensive - many can be cheaper, particularly in the longer term - but the process of adapting, refining and implementing them is not "business as usual".

As with any change, there are challenges involved. Time, research and discussion may be needed before an appropriate solution is agreed upon, and this can appear risky for schedule and budget.

Engineers are ideally positioned to bring a positive mindset to the project team. Engineers solve problems. Is this not exactly the kind of practical challenge to ingenuity that the profession should most relish? The vision of a waste-free future, powered by a regenerative economy, is far from utopian: it's already being integrated into some of the UK's most prominent infrastructure projects, and in London is embedded in the mayor's planning policies.

Two examples: the specification for HS2 incorporates a detailed data trail specifically to enable the maintenance, adaptation and reuse of components are they age or as the country's transport needs change in ways we cannot yet predict.

In the construction of Thames Tideway, not only is excavated material being recycled as standard, but larger redundant elements are being carefully dismantled in larger segments for reuse at other sites.

Designing for net zero carbon and a circular economy

Within a circular economy framework, it makes sense to approach project design with the joint goals of net zero carbon emissions and zero waste. Readers of this Carbon Project blog series will recognise the following recommendations:

  • Consider "build nothing" as the first option - can the need that the project is designed to address be met through any other means, including repurposing or adapting existing assets?
  • Assess and plan for the cradle-to-cradle lifespan of every asset.
  • Use recycled and renewable materials and minimize the requirement for new or finite resources in repair, maintenance and usage, as well as in construction,
  • Design for end-of-life disassembly by providing as much data as possible to support future designers in their efforts to reuse every component.

Re-imagine your industry and the skills it will need

It is clear that consultancies and engineers will increasingly thrive by developing their skills in low carbon design, including sustainable maintenance and adaptation.

Yet the opportunities created by the change that is coming go beyond the design and construction of assets. The implementation of the circular economy's own infrastructure will require a transformed waste sector and with it, a wide range of expertise that is still in short supply.

The traditional functions of waste processing will be wholly replaced by the logistics and facilities required for disassembly, removal, storage, re-testing, re-certification, repair and reuse. Industry bodies are already working to ascertain what new safety standards and certification might look like for reclaimed and recycled materials, and this process will continue. Enormous opportunities are opening up for the development of digital skills that relate to tracking and monitoring the use and reuse of materials, e.g. Globechain and Qflow.

As mentioned earlier, reliance on finite resources limits our future. Human innovation, however, is a limitless resource. In serving the preservation and prosperity of our world, engineers should not hesitate to use it boldly.

This blog is part of The Carbon Project series, exploring how engineers can contribute to achieving net zero in UK infrastructure.

ICE’s Research & Development Enabling Fund is currently looking for projects that help infrastructure professionals in the effort to track and reduce carbon. And if you’ve saved carbon on your engineering project, you can apply to be an ICE Carbon Champion