INTERVIEW: Will Arnold, Head of Climate Action, The Institution of Structural Engineers.

An engineer’s perspective on The Real Cost of Climate Change.

Welcome to KISTERS’ ongoing exploration of The Real Cost of Climate Change. We believe that collaboration is key to finding effective solutions which is why we’re reaching out to neighbouring industries all over the globe for their invaluable insights.

In this exclusive interview, we’re honoured to be joined by Will Arnold, CEng FIStructE FRSA, Head of Climate Action at the Institution of Structural Engineers. Join us as we delve into his expert perspective and uncover the critical steps and strategies needed to make better decisions for a sustainable future.

About Will Arnold. Will is a Fellow and staff member of The Institution of Structural Engineers, responsible for embedding sustainability action into all aspects of the institution’s work. He is responsible for driving the update of minimum standards for institution members, developing supporting guidance, and leading collaboration with wider industry. Will was the lead author of Part Z (an industry proposal for embodied carbon regulation in the UK) and is helping to deliver both the UK Net Zero Carbon Buildings Standard, and the Built Environment Carbon Database. Prior to joining the Institution, he worked as a practising structural engineer for more than a decade at Arup. In recognition of his work instigating change in the field of structural sustainability, Will holds the IStructE President’s Award, and the Memcom Outstanding Achievement Award.

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THE INTERVIEW.

KISTERS: Can you briefly explain your role as the Head of Climate Action for the Institute of Structural Engineers?

Will Arnold: We’re a membership organisation with about 30,000 members worldwide. Approximately two thirds are based in the UK, and the rest are overseas. We’re the world’s largest institution that specifically handles structural engineering.

In 2019, the institution concluded that sustainability and safety are essentially the same thing. So we decided we had to put sustainability on par with how we’ve talked about safety. The only difference being about whether you’re causing harm quickly or slowly. At the end of the day, it’s still causing harm. In 2020 I was brought on board to integrate sustainability into all our practices.

Since the summer of 2020, we’ve increased sustainability training and updated our membership standards. To become a chartered structural engineer with our institution now requires understanding and designing for carbon emissions. This shift is crucial, especially considering that around 10-12% of global emissions are due to structural materials, primarily concrete and steel.

KISTERS: How should the built environment adapt for greater climate resilience?

Will Arnold: Climate resilience requires a delicate balance between mitigation and adaptation. In places like the UK, we’re grappling with more frequent storms and flooding. However, challenges vary globally. For instance, some regions face intensified typhoons, while others battle drought and wildfires. These changes affect the stresses our structures must withstand, which are anticipated to increase.

It’s essential to strengthen existing structures, but not by indiscriminately adding materials. A structure is either safe or it’s not; adding excess material beyond what’s required for safety isn’t the answer.

KISTERS: Structural engineering is deeply rooted in math, science, and physics. How does the industry incorporate predictive data for future climate changes?

Will Arnold: Our industry primarily follows design codes which outline the forces a structure should be designed to withstand. These codes are constantly reviewed and updated based on the latest research and predictive data. For instance, after discussing with a wind expert, it’s evident that wind forces are expected to intensify over the century. However, the exact magnitude remains uncertain. Predictions vary from an increase of 10% to as much as 1,000% due to inherent unpredictabilities and feedback loops.

KISTERS: Given this unpredictability, how does the industry approach worst-case scenarios?

Will Arnold: The worst-case scenarios are really important for design, as it is these that we typically design for. The committees responsible for our codes are actively addressing this, ensuring that the numbers we use are up-to- date. Engineers typically use these predetermined values to simplify their designs.

KISTERS: Our report shows that flood costs this decade are estimated to reach $41 billion, and projections for the next decade are at $217 billion. With the frequency and severity of storms increasing, does this raise concerns in the structural engineering industry?

Will Arnold: Absolutely. The repercussions of flooding on a structure significantly depend on its materials. While it’s a pressing concern, from a purely structural standpoint, it might not be as critical. But for other disciplines within the building industry, it poses significant challenges.

KISTERS: Are there sustainable alternatives or solutions to tackle these issues, especially in flood-prone areas?

Will Arnold: Yes, the industry is actively exploring sustainable solutions. While the immediate reaction might be to construct concrete flood barriers around cities, that approach would consume vast amounts of high-carbon materials, exacerbating the problem. Nature-based solutions offer a more sustainable path. Flash floods, for instance, often result from rapid water flow into rivers. By investing in terracing and rewilding, we can slow this flow, thereby mitigating flood risks. Such methods not only address flooding but also provide added sustainability benefits, unlike concrete barriers.

KISTERS: Given the proactive measures the institute seems to be taking, how can the government further assist the construction sector in its climate action initiatives?

Will Arnold: Currently in the UK, while we regulate emissions stemming from energy usage in buildings, there’s no regulation controlling emissions from embodied carbon, which refers to the carbon footprint of building materials. This is a significant oversight.

Our open-source regulation proposal, Part Z , has the backing of over 200 firms, including prominent names in the industry. Implementing such a regulation is the most substantial step the government can take to mitigate our industry’s carbon footprint. Without such standards, there’s no uniformity in tackling these emissions, leading to inconsistent practices, increased costs, and delayed progress.

KISTERS: It sounds like an obvious solution. Why hasn’t it been implemented?

Will Arnold: It’s perplexing. However, there’s a glimmer of hope. The UK government has now funded a research project on this very topic. A renowned engineering consultancy has been tasked with assessing the feasibility and impact of such a regulation. Although it seems more of a “when” rather than an “if”, the pace at which it is being addressed is slower than many of us in the industry would prefer.

KISTERS: Do you believe the role of structural engineers will evolve in the upcoming decade? If so, how?

Will Arnold: Certainly. Reflecting back just five years, the common structural engineer would typically join a project quite late, receiving drawings that architects, project managers, and other stakeholders had already developed. Their primary role would be verifying column sizes and other foundational elements.

However, trends, particularly in affluent countries and cities, indicate a shift. Structural engineers are now being integrated much earlier in the design process. They’re consulting on potential modifications to existing buildings, offering insight before plans are cemented. For instance, a client may wonder if they can add three more storeys to an existing six-storey office building. Such early-stage evaluations now often fall to structural engineers.

KISTERS: So, it’s about more effective collaboration within the industry?

Will Arnold: Precisely. Rather than sticking with the status quo, collaboration is becoming more commonplace. Mega projects like The Shard had engineers involved from the get-go, which yielded a more efficient design. The same principle can be applied to projects of any scale.

KISTERS: Policy plays a crucial role in enabling this change, right?

Will Arnold: Absolutely. Regulatory shifts, like those targeting embodied carbon, are potent catalysts for change. Instead of retrofitting designs to be more sustainable later in the process, integrating sustainable practices from day one can be more cost-effective. Proper regulation ensures these considerations are integral from the project’s inception.

KISTERS: What challenges does this present for your role and the broader engineering industry?

Will Arnold: One prevalent misconception is that more sustainable buildings are inherently more expensive. Costs can be controlled by integrating sustainable practices early in the design process, and there’s also the long-term cost of inaction to consider. The built environment accounts for roughly 37% of global emissions. If left unaddressed, the repercussions – such as flooding due to climate change – can be profoundly costly. These externalities are often overlooked in the design phase because their impact isn’t immediate. However, the data indicates that the costs associated with climate disasters are set to eclipse GDP growth, underscoring the urgent need for action.

KISTERS: And yet, long-term goals sometimes seem intangible to stakeholders.

Will Arnold: That’s the challenge. While we have targets set for 2030 or 2050, many feel detached from these distant goals. But the IPCC has emphasised the importance of immediate action within this decade. The goal shouldn’t be just about what happens by the end of the century but what we can achieve by 2030. The current trajectory is alarming, but it’s not too late to make a difference.

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End.

The Real Cost of Climate Change 2023 Report