06 Sep 2021 By Greg Pitcher
Progress on protecting buildings from the impact of climate change is behind where it should be, and the need is only becoming more urgent. Greg Pitcher reports
“Climate change has arrived.”
That was the clear message in a key paper handed to ministers this summer. The declaration in the Climate Change Committee’s Advice to Government report came just weeks before Germany was hit by devastating floods and London was deluged by heavy rainfall.
And the committee, set up in 2008 to advise Westminster on progress towards minimising and preparing for global warming, had more stark news: “Further warming is inevitable,” the report stated, part of a broad suite of studies forming the committee’s third risk assessment.
Reading on, ministers learned that 7,000 people could die from heat-related causes in 2050 – up from an average of 2,000 per year at present.
Hathern, Leicestershire, UK. 19th January 2021. UK weather. Children paddle near a car stranded in flood water. Storm Christoph is set to bring widespread flooding to parts of England. Credit Darren Staples/Alamy Live News.
Then there is the risk from increased rainfall. Figures from the committee show that expected annual damage to property from surface-water flooding could soar from £139m today to £312m by the 2080s. This could affect not only individuals but critical infrastructure such as power stations and water-treatment plants.
After that bleak UK assessment came a global report from the Intergovernmental Panel on Climate Change (IPCC), branded by the head of the UN as a “code red for humanity”.
Hope, where it appears, lies in mitigation rather than prevention of a changing climate. The UK “has the capacity and the resources to respond effectively,” the committee report says.
But here’s the sting: “Alarmingly, new evidence shows that the gap between the level of risk we face and the level of adaptation under way has widened,” the report adds. “Adaptation action has failed to keep pace with the worsening reality of climate risk.”
Building flood defences and better designed buildings are just two of the measures required – and construction will play a key role in both.
The committee urges ministers to take firm action, including updating Building Regulations and the National Planning Policy Framework to encourage introduction of measures such as passive cooling and sustainable drainage in new and refurbished buildings.
The Building Safety Regulator – created in the wake of the Grenfell Tower tragedy – could also have a role to play in ensuring greater climate resilience, according to the report.
Mott MacDonald UK and Europe sustainability lead Kim Yates says the construction industry needs to think about changing weather patterns in everything it does.
“It is not just projects looking specifically at resilience that are the future; we have a duty of care to take climate resilience into account on all our projects,” she says, conceding it is “extremely challenging” in the face of uncertainty.
“You have to build an asset that is fit for a future where we don’t decarbonise fast enough. You can’t concentrate on a low-carbon material that would see a building fall over when it gets hotter”
“In our flood-risk assessments for highways projects, for example, we look to ensure that the drainage design will accommodate a 40 per cent increase in flooding,” Yates says. “This is in line with government guidance and, on the basis of our current climate change modelling, this is enough. But what if our models are wrong? How do we allow for the fact that our models may be too optimistic?”
Storm events that used to happen every 1,000 years are now happening once a century, she explains, and it is hard to know what a one-in-100-year flood will be in a few decades’ time.
In July, two regions in the west of Germany saw almost twice the amount of rainfall they usually receive throughout the month in just 48 hours. Days later, an even more extreme deluge landed in the Chinese city of Zhengzhou in just one hour. Both incidents claimed a number of lives. Later the same month, hospitals and tube stations in east London were hit by flash floods.
In the UK, Yates says resilience measures have to be considered within a climate change context when environmental impact assessments are submitted to planning authorities. However, such impact assessments are currently only required for a “small proportion” of schemes and those are usually selected on the basis of environmental impact rather than resilience requirements. “The regulatory drivers are not there to consider climate resilience in everything we build,” Yates says.
A government spokesperson insisted in a statement that all developments should take climate adaptation into consideration. It has also launched a research programme for securing infrastructure (see box, below).
In response to the Climate Change Committee’s warnings, the UK Government has launched a £5m research programme to help it become “more resilient to the impacts of climate change”.
The four-year scheme, called Climate Services for a Net-Zero Resilient World, aims to help the country respond to the impact of global warming on national infrastructure – including heatwave impacts on buildings, power stations, electricity networks and flooding.
It is being led by a consortium of environmental scientists, including those from University College London and the UK Centre for Ecology & Hydrology.
Climate minister Anne-Marie Trevelyan, who is also construction minister, says: “This new programme brings together the brightest and best climate scientists, universities and research institutions from across the country to provide us with the latest tools, advice and research to inform future climate policies at a national and local level. This research will be vital to ensure we’re making the best possible choices on our journey to net-zero, making certain the UK is adaptable and more resilient to the effects of climate change.”
Despite the clear message from the Climate Change Committee, preventing – or minimising – global warming still holds sway as a primary focus. The Paris Agreement saw world leaders promise to keep the change in global warming below 2 degrees above pre-industrial levels, while the UK Government has made its bold pledge of net-zero carbon emissions by 2050.
Climate Change Committee adaption member Michael Davies admits there are challenges for governments trying to push resilience measures alongside carbon reduction: “You have to adapt to climate change that has happened and will continue to happen regardless of net-zero targets,” he says. “But it is challenging to have metrics and clear messaging for adaption.”
Yates insists the two goals must be aligned: “We are thinking about decarbonisation and climate resilience from the outset of any projects we embark on,” she says. “It is built into our processes.”
Sochi, Russia. 23rd July, 2021. A rescue worker helps a man to walk through water in a flooded street in Sochi’s Khostinsky District. A storm warning is issued for the city of Sochi; forecasters warn of flood threat as water level rises in rivers, and mudslide threat. Credit: Dmitry Feoktistov/TASS/Alamy Live News
The company employs specialists who can interpret meteorological data and advise on adaption strategies, as well as carbon-focused infrastructure professionals. “For our engineers and designers, it’s about being climate-change literate and understanding the [trends] so we can build in resilience to compensate,” Yates adds.
However, trying to reduce carbon emissions while building to withstand more extreme conditions can put the two goals in conflict. “We are trying to arrest climate change by building in a low-carbon way, which requires new materials and techniques,” Yates says. “You have to be aware of whether your new low-carbon concrete will survive with higher levels of carbon dioxide in the atmosphere.
“You have to build an asset that is fit for a future where we don’t decarbonise fast enough. You can’t concentrate on a low-carbon material that would see a building fall over when it gets hotter.”
Projects to protect people against changing weather will become increasingly prevalent over the coming years, she predicts: “We had a project in Bangladesh looking at the resilience of bridge assets to climate change, making sure the infrastructure stays in place with higher carbon dioxide levels, fluctuating water levels and so on. In the UK, making sure our building stock can cope with wetter winters and hotter summers is important from a climate-resilience perspective.”
Clients are also becoming more aware of the benefits of building in resilience, according to Yates. “We have worked on projects where we identified the risk of, for example, tiles blowing off in high winds, explained it to the client, and the design was changed,” she says. “It can be a differentiating factor in a bid. If you do not have a good grip on climate change and the impact it will have, you will have a lot of issues in the future as there is increasing pull from clients to ensure it is dealt with.”
Dr Anastasia Mylona, head of research at the Chartered Institution of Building Services Engineers, says climate change will exact a number of impacts on the built environment. Intense rainfall can lead to flash flooding in unexpected places, and potentially cause landslides that damage infrastructure, she adds. On the other side of the coin, droughts can cause subsidence and even create the soil conditions for further flooding.
“Extreme events will become more frequent, more extreme and more destructive,” she says. “There is a cycle because, if rail lines buckle in the heat, then the engineering to fix it is carbon-intensive and uses resources. You need more of everything if you keep fixing things in the way we have been.”
Mylona stresses that engineers need to reduce their impact on the environment, slashing embodied carbon and actually doing less new-build work. But she adds that where new buildings are created, they need to be extremely well considered: “Have a good understanding of the risks of the future and ensure your buildings can deal with them,” she says. “We still build homes in floodplains – fair enough – but please have a strategy. There is very little thought going into making developments more resilient.”
Schuld, Germany. 15th July, 2021. The destroyed bridge in the village in the district of Ahrweiler after the storm and flood. At least six houses were destroyed by the floods. Credit: Harald Tittel/dpa/Alamy Live News
A lack of specific design criteria and resilience-performance levels in planning guidance leaves dangerous grey areas, Mylona adds. “Everyone interprets advice as they want. You have fully glazed towers in London, homes built wherever, and that tells you no-one is checking how new buildings and infrastructure will cope with future events.”
Lack of knowledge is not an excuse available to modern day town planners and construction clients, she adds. And climate-resilience measures do not have to be over-complicated or expensive. “We have a lot of information available. Councils and organisations like the Environment Agency have a lot of tools. They know which areas are more prone to heat or flooding. Plans can be put in place. You can add shading devices such as shutters or overhangs to increase the thermal comfort of buildings – we are talking about small engineering interventions. It is common sense but it’s missing. When you build a development you can think about where the water will go – using sustainable drainage systems such as swales. Other countries deal with these risks all the time and have solutions in place.”
Echoing the Climate Change Committee, she calls for the government to intervene. “Engineers can’t solve the problem on their own. They need support and motivation. Private clients and councils are sometimes motivated to do the right thing but unfortunately the vast majority are reliant on profit. Without a policy driver it’s very, very difficult for engineers to tell clients to implement something.”
Sadly, a big tragedy may be needed to influence ministers, she adds. “Every time we have a shock event, everybody talks about it. The fire at Grenfell Tower changed so much in terms of policy and regulation. Unfortunately, people in government respond much quicker and more effectively after a disaster.”
The government insists the planning system does take factors such as flood risk, coastal change, water supply and rising temperatures into account. A Ministry of Housing, Communities and Local Government spokesperson said in an emailed statement: “Our national planning policy is clear that local councils should take into account the impacts of climate change and responsibilities to the environment, as well as prioritise building on brownfield and urban land, so that we put green spaces, communities and environmental protection at the heart of the planning process.
City of London, Square Mile, panorama shows completed 22 Bishopsgate tower, London, England, United Kingdom, Europe – Will the gleaming glazed towers in London cope with future climate events?
“We are also ensuring new homes are producing less emissions and that new housing developments are leaving nature and biodiversity in an overall better state than before development.”
A consultation earlier this year called Future Building Standards also set out proposals to reduce the risk of overheating in new residential buildings via Building Regulations. However, Mylona stresses that contractors do not need to wait for the future to prepare to deliver climate-resilience work. “Engineers are in a good position technically to propose and implement solutions to improve the resilience of the built environment but they need the support of regulation, common understanding and sometimes funding.”
Baroness Brown, chair of the Climate Change Committee’s adaption team, describes adaption as the “Cinderella” of climate policy. It is still “sitting in rags by the stove, under-resourced, underfunded and often ignored”, she warns. At some point soon, as this metaphor implies, we are due a miraculous transformation. In the absence of a fairy godmother, it would benefit contractors to ready themselves now if they hope to live happily ever after.
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