“What I’ve found surprising is the number of heatwaves we’ve had and the short duration of time between each of them,” the chair of IMechE’s Climate Change Adaptation Working Group says from the stifling heat of his converted attic. “What we’re experiencing this summer, I didn’t expect to see until the late 2040s, 2050s… the [forecast] scenarios are really trailing what we’re observing in the environment.”
While renewable energy and efficiency measures aim to mitigate climate change, adaptation is also needed to keep up with the pace. Focusing that work on extreme heat and lower rainfall might seem prudent in the blazing August sun, but the phenomenon could also lead to some very different conditions. Heavy rainfall after a drought can lead to flash floods, for example, in a domino effect of disruption.
Blowing hot and cold
There could be even more surprising and disruptive changes at a regional level. Sweltering in temperatures of up to 38ºC, it is hard to imagine it will ever be cold again, but elevated carbon dioxide levels could lead to extremes at both ends of the thermometer.
Recent reports show that a slowdown or collapse of the Atlantic Meridional Overturning Circulation (Amoc), which brings warm water up from the tropics and is largely responsible for the UK’s mild climate, is looking more likely than ever. If that happens, the UK could find itself with a climate similar to Canada’s, with both hotter summers and colder winters.
The threats to climate stability are piling up and everyone is at risk once they start to tumble down. Urgent preparation is needed to ensure our systems can survive the rest of the 21st century – and engineers have a vital role to play.
‘No-regrets decisions’
The warning was severe. The UK is, according to an IMechE report published in early September, “preparing for yesterday’s weather while tomorrow’s climate has already arrived”.
Published in partnership with the UK Infrastructure Operators Adaptation Forum, Preparing the UK for Compound Events states that the country is unprepared for the climate domino effect, in which one extreme weather event follows another. Based on an earlier workshop by the two organisations – with 70 attendees from industries from healthcare to food, as well as engineering sectors including construction, energy and rail – the report set out how an infrastructure failure in one sector could trigger others elsewhere in a series of “cascading risks”.
The work also highlighted uncertainty around Amoc and the related North Atlantic Subpolar Gyre (SPG). According to a 2024 report by the Institute for Public Policy Research, the chance of the SPG collapsing this century is estimated at 36-45%, with some models suggesting it could happen as early as the 2040s. That would have dramatic consequences for the UK, particularly on food production.
These threats in the short, medium and long term place some paradoxical pressures on engineers. Infrastructure and housing need to handle periods with much less rainfall, followed by relentless downpours. Buildings need to stay cool in blazing summers, but keep occupants warm in potentially much colder winters. Those same winters could, while overall being drier, have more storms, with higher wind loads and different types of precipitation.
Dr Tim Fox
Those conflicting pressures put engineers in a difficult position: over-design and you risk unnecessary resource consumption; under-design and you end up with infrastructure failing. Thankfully, some approaches can relieve that pressure.
“If I’m designing against the current expectation of hotter, drier summers, then I should be thinking, as I do that design, ‘How could this design be modified, adapted or enhanced… at a later stage to cope with colder winters?’” asks Fox, one of the IMechE report authors. “It’s all about ‘no-regrets decision making’, allowing for adaptation pathways at a later stage that provide you with an opportunity, essentially, to defer investment… We can have thresholds, decision points within our planning, that enable us to change tack.”
Designers should introduce new layers of stress-testing into their process to fend off cascading threats, he adds, including the compound risks of floods, wildfires and other extreme weather.
New storylines
Adaptation pathways feature in a lot of the best practice highlighted in the report, agrees fellow author Dr Laura Kent, government affairs and policy manager at IMechE. These “allow infrastructure owners to make decisions incrementally as the risks evolve, rather than committing to a single solution from the outset,” she says.
“It’s still moving things forward; it’s just building in decision points along the way. Infrastructure owners can adapt differently or pursue alternative options when required.”
The Thames Estuary 2100 (TE2100) plan is a good example, Kent says. “Developed to address increasing tidal flood risk in London and the Thames Estuary, the plan combines long-term objectives with flexibility over how and when interventions are implemented,” says a case study in the report. “Rather than committing to a single solution, TE2100 identifies a sequence of potential actions and uses regular monitoring of sea level rise, climate projections and flood defence performance to determine when additional measures are needed.”
Narrative storylines are another “really valuable tool”, Kent adds, helping engineers, operators and entire organisations understand the likely result of complex future climate scenarios. These are used in the adaptation strategy at Heathrow Airport, for example, where potential hazards such as extreme heat, flooding and high winds are linked to operational issues such as flight disruption or passenger numbers.
“That’s a really good example of how an organisation can really elevate climate adaptation as a priority,” Kent says. Of course, planning is not enough. Successfully preparing for the climate cascade will involve deployment of cutting-edge techniques and technologies. This will likely include “better uses of sensors and some digital monitoring, probably predictive analytics and probably AI-enabled tools to help operators identify emerging vulnerabilities before failures occur,” Kent says.
Prevention, not cure
Another case study shows what this could look like. Following several extreme weather events, Denmark’s rail operator, Banedanmark, has increased its focus on climate-related vulnerabilities, including the development of a comprehensive monitoring programme.
“Sensors are being deployed at selected high-risk locations to collect data on water levels, ground conditions and asset performance. Combined with climate risk assessments and improved asset information, this enables a better understanding of how climate hazards affect the railway and where vulnerabilities are most significant,” the report says.
The programme also uses information from localised failures and disruptions to refine analytical models, improving understanding of vulnerabilities over time and supporting increasingly evidence-based adaptation decisions. Different solutions will come to the fore as other engineering industries adapt, Fox says. In construction, for example, heat pumps can also cool buildings, making them suitable for hotter summers and colder winters alike. Better insulation can similarly keep buildings cooler in summer, as well as warmer in winter. Mediterranean-style shutters, meanwhile, could keep buildings cool in summer and protect from storm damage during winter.
If the above solutions sound slightly low-tech, Fox has an explanation. “We haven’t reached a point, yet, of raised awareness,” he says. “If research programmes got in place that enabled engineering researchers to think about how you could tackle these changes in the projections that we are expecting, we would see some very fruitful and innovative outcomes.”
‘It’s all interconnected’
Some research programmes are, thankfully, already in place. One potential source of innovation is Renew-Futures: Regenerative Design for Beautiful, Inclusive and Ecological Neighbourhoods, which received an €8m Horizon Europe grant in September to “develop practical tools and a transferable framework for creating more sustainable, liveable and climate-resilient neighbourhoods”.
Involving researchers from the University of Bath’s Centre for Regenerative Design & Engineering for a Net Positive World (Renew) and 14 partners across Europe and Canada, the four-year project will investigate how to design neighbourhoods in an integrated way, considering factors such as water cycle, energy, carbon and biodiversity, alongside less tangible ones such as wellbeing.
Drawing on expertise across engineering, architecture and urban planning, the consortium aims to help create neighbourhoods that cope better with droughts, flooding and extreme weather while reducing costs, improving public spaces and supporting community wellbeing.
Based on data from 14 European case study cities, the team plans to develop a digital twin-based ‘regenerative neighbourhood design tool’ that could allow communities to simultaneously optimise multiple factors by modelling the water use, carbon emissions, building materials and social aspects of a neighbourhood. “We want to create neighbourhoods that are closed – almost self-supportive or self-sufficient – in water,” project co-lead Professor Jan Hofman tells Professional Engineering.
“So that means we are going to look into systems where we can recover wastewater… We can also include aspects such as rainwater harvesting to make that area self-sufficient in water and perhaps also tackle things we saw this summer, where we had very dry periods.”
Professor Jan Hofman
But simply looking at water is “not enough”, Hofman continues. “It’s all interconnected… if the water quality is not good, it has an impact on health. So all these aspects need to be integrated in the system.”
Five demonstrator neighbourhoods will showcase how the approach can be adapted to different climates and local challenges, from heavy rainfall in northern Sweden to water scarcity and extreme heat in Portugal.
Specific technological solutions to climate pressures will vary from area to area, says project co-lead Dr Sara Biscaya, but nature-based solutions, water reuse and renewable energy are all likely to be important.
The key will be how they interact and work together for a particular neighbourhood. “We can end up designing responses in isolation – a flood solution, a heat solution, an energy solution,” she tells Professional Engineering. “But we know that these systems interact. So a green space, for instance, might help retain storm water, reducing overheating, supporting biodiversity and improving wellbeing at the same time.
“But an intervention that performs very well against one risk might create unintended consequences elsewhere. So what we’re interested in understanding is those interdependencies and making them visible within the design process… You cannot really address climate resilience by designing for one extreme event only; we need neighbourhoods that can function under changing and sometimes competing environmental conditions.”
Dr Sara Biscaya
Positive tipping points
The climate cascade threatens more than just our homes and neighbourhoods. Power, transport, healthcare and supply chains are all vulnerable, so an engineering-led systems approach will be vital to keeping infrastructure online.
“We need the governance, we need better shared data and we need better cross-sector coordination,” says Kent.
Specific measures called for by IMechE include transferring climate adaptation responsibility to the Cabinet Office, mandating adaptation reporting through the Adaptation Reporting Power for critical national and public infrastructure, and investing in adaptation research to enable effective policy.
Engineers are “particularly good at thinking about how systems interact… helping organisations understand how energy, transport, water, communications and other essential services all rely on each other,” Kent says. “We’re hoping to see people stress-testing their infrastructure against compound events and those high-impact, low-likelihood events.”
The Institution is engaging with officials and policy leads in government, Kent adds, and will continue to work with policymakers, regulators and other stakeholders.
If some engineers can stop the first dominoes from falling, it will give others more time to tackle the root causes of climate change. There could even be “positive tipping points” where “progress can become rapid and self-reinforcing”, according to new research from The Earthshot Prize and the University of Exeter. The report, entitled Positive Tipping Points: Accelerating system change to repair our planet, identified 51 solutions that could help quickly repair the planet, including development of urban green infrastructure and mass adoption of electric vehicles.
Clean energy is already acting as a “master cascade”, according to the research, with falling costs for solar power unlocking further deployment and driving costs down even more.
Conversation is needed – but action is even more important, Kent says: “We could spend forever talking about what could happen, the uncertainty, whether it will or will not happen, what degree of warming will we get, how many hot days, how many wet days will we have? But at some point, we need to stop debating every possibility and start getting on with adaptation.”
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.