The UK’s hottest day of the year exposed just how little the country’s political leaders have done to prepare for climate change: transport chaos ensued, hospitals were closed, workplaces became unbearably hot and fires destroyed homes across parts of England. Though the UK is making progress in reducing emissions, climate adaptation has been “under-resourced, underfunded and often ignored”, according to the UK’s independent Climate Change Committee. With the climate crisis bringing extreme weather to our isles with more frequency, it’s clear that governing bodies need to devise a serious adaptation plan.
Cities have a critical role to play in adapting to withstand climate change. Worldwide, they consume 78% of the world’s energy and produce more than 60% of global emissions while accounting for less than 2% of the Earth’s surface. Cities are also projected to grow because the climate crisis is causing mass migration to cities. They are heating up at twice the global average rate due to the urban heat island and rapid industrialisation. By 2100, some cities could be 4C hotter on average.
So what are the practical ways UK cities can start adapting to a changing climate? Novara Media spoke to three urban adaptation, architecture and engineering experts to find out.
Adopting nature-based solutions.
Helen Pineo, an academic at the UCL Institute for Design and Engineering and author of Healthy Urbanism, believes two of the most significant issues facing cities are warmer temperatures and extreme weather events, such as longer-lasting hot spells, increased risk of flooding and wetter winters. “Green infrastructure – and what a lot of people call ‘nature-based solutions’ – can be a positive way to make our cities more resilient to the changes they face,” she says.
This looks like having sustainable drainage systems that reduce the impacts of excess rains alongside roads, to keep streets and pedestrians cooler. Other solutions suggested in a UN report include painting roofs white to reflect sunlight, green corridors (areas of habitat connecting wildlife populations separated by human activities or structures) and district cooling systems.
With so many solutions to combat the urban heat island effect, it could be hard to know where to start. “One of the newer concepts within urban planning is to assess the urban heat island vulnerabilities across a city – so looking at which parts of the city based on their makeup and the building types and the amount of green space, are vulnerable to overheating,” Pineo says. This information could then target new developments to meet better sustainable building targets or pressure the government to put in more green infrastructure through government grants. The academic says special attention needs to be paid to socio-economically vulnerable areas of the city, where planning decisions have been informed by racism and classism, as they are often disproportionately affected by the climate crisis.
The ‘Grey to Green’ development strategy devised by Sheffield City Council is an excellent example of employing nature-based solutions in urban areas. The design connects parts of the city with its waterways, flowing rainwater back to its rivers in a way that mimics nature. It has also introduced multi-layered drought-tolerant planting to combat air pollution, reduce carbon emissions, and strengthen biodiversity.
Ensure better drainage and flooding systems for flash floods.
As the UK experiences longer hot spells, flash floods are likely to increase in frequency and intensity.“Paving over natural areas means the water can’t penetrate the ground, and this is partly why cities have difficulty managing water during storms and then end up flooding,” Pineo explains. In London, for example, almost a quarter of the city is made of gardens, but this reality is fast changing as gardens get covered by decking or concrete to provide car parking or reduce maintenance. It’s estimated that an area two and a half times the size of Hyde Park is lost every year.
An answer to this could be found in sustainable drainage systems (SuDS), which mimic natural drainage systems and are engineered to provide an alternative to directly removing surface water through networks of pipes and sewers. Not only can SuDS reduce surface water flooding, but they also improve water quality and the biodiversity value of the environment. SuDS are already being incorporated into cities all over the UK.
Fergus Anderson is an associate consultant at Buro Happold’s sustainability team, a company providing engineering consultancy, design and planning for buildings, infrastructure, and the environment. One of Buro Happold’s recent projects saw collaboration with Subak farmers in Bali to develop ideas for solutions, based on their indigenous, traditional farming methods, that cities might adopt in 2040. “I think it’s generally accepted that people want to bring nature into cities, and we see this as part of the role of tackling climate change and the impacts of climate change,” he says. “Yet there’s a lot of talk about pristine nature in cities, and I don’t think that’s the answer.”
Anderson believes that engaging with nature must involve studying its natural processes and using this information to guide the design, so when it comes to tackling upcoming flood risks, he argues that local projects should be holistic. “A lot of the approach to risk in cities at the minute is to create barriers,” he says. “If flooding is a risk, people might be compelled to build a massive wall. When actually, there is a need to be more adaptive. Maybe we should let some spaces flood and tailor our programming of space to match based on those environmental conditions.”
Cities today, Anderson says, are increasingly disconnected from nature and contribute to people not seeing themselves as part of living systems. “What we can learn from indigenous worldviews and indigenous wisdom is that [they see living in nature] as a reciprocal relationship, placing a huge amount of emphasis on stewardship of those resources and the living world and sort of intergenerational thinking,” he observes. “It’s a real contrast to where cities are today.” He hopes that nature-based adaptive urban design can start challenging this dynamic.
Insulating Britain and building better.
Updating Britain’s infrastructure to withstand climate pressures means preparing for all weathers. “When it comes to our perception as architects, as designers and as citizens in the UK, we need to realise that the climate we’re now designing for is not just a warming climate, but a climate with more extreme temperature differences,” says Rachel Harris from the Architects Climate Action Network (ACAN). “[In the UK], we come from a long-standing tradition of ‘we need to heat our houses in the winter’ when actually, we need to think about solutions for heating and keeping our houses cool.”
It might be tempting to think that the convenience of air conditioning or heating will solve this problem, yet such solutions only exacerbate the climate crisis due to their need to consume energy. Instead, Harris suggests a cultural mindset shift to how we regulate indoor temperatures. “We must look towards passive principles and techniques to help keep us comfortable. Switching on AC when it’s too hot and heating when it’s too cold takes energy and uses resources that we really don’t have. We need to learn from simple, tried and tested traditional or vernacular solutions throughout history.”
So what can be done? When it comes to new buildings, the architect believes that getting the orientation, airflow, and shading is vital. “We need to get the orientation of houses right if we can, and if the site allows it – to maximise the potential of passive principles to make sure that we can shade our windows from the summer sun but benefit from winter solar heat,” she says. “If we’re designing apartments, making sure they are dual aspect to enable cross ventilation.” We should look to traditional cities in warmer climates for urban design inspiration, says Harris, as they have shaded, narrow streets and create cooler microclimates that enhance airflow.
With 80% of the houses that will be around in 2050 already built in the UK, retrofitting and improving (the performance of) existing building stock is equally as important. Groups like Insulate Britain are demanding that the government retrofits existing houses by insulating them to reduce the active heating and cooling requirements. Britain has some of the leakiest housing stock in Europe, meaning we use far more energy to heat our homes than our neighbouring countries. It would cost around £5bn for the government to retrofit existing houses. Such a project would save not just money for climate adaptation further down the line but also lives.
Though retrofitting would be a welcome move to conserve energy, Harris points out that this still needs to be done sustainably. “The problem is that the government tends to look towards heat pumps when looking at lower-carbon solutions, but they’re still active options that consume energy. In order to decarbonise our built environment, we must ensure that we maximise passive strategies and improve building efficiency before employing any active ones.”
Rethink transportation and embrace 15-minute cities.
With more extreme climates ahead of us, transportation infrastructure is under severe threat. Already in the UK, there are continuous train disruptions due to felled trees after storms and fires, unworkable lines due to floods or overheating, and roads are melting in high heat. Adapting transport infrastructure to be resilient to extreme weather will be one of the more costly tasks. So what can be done to address these issues and the demand to move around?
“Transport is the solution to something. We take a lot of these systems for granted, but actually, it’s important to take a step back and think about what issue transport is solving, and it is one of connectivity between people, services and places of work,” says Fergus Anderson. “If we were to take transport out for a second, could we design our cities to be 15-minute or 20-minute neighbourhoods where people need to use public transport less?” The 15-minute-city idea relies on everyone living in a city to have access to essential services within a 15-minute walk or bike ride. Paris is one of the major cities to adopt the 15-minute-city plan to reduce car traffic and carbon dioxide emissions to improve the well-being of residents.
Since the beginning of the pandemic, people in the UK have experienced significant shifts in how they work and travel. So why couldn’t the climate crisis force us to reconsider transport? “If we don’t start looking at things like design codes, which are so out-of-date now relative to the kind of heat and rate that we’re seeing, there’s a risk that we lock in these impacts for a long time and lock ourselves into higher costs to adapt,” Anderson adds.
Reducing consumption is at the centre of everything.
As well as pushing for more sustainable performance of buildings and infrastructure, one thing that needs to be considered is building with less carbon-intensive materials. In 2018, the UK’s building and construction sector accounted for 39% of energy and process-related carbon dioxide emissions, 11% of which resulted from manufacturing building materials such as steel, cement and glass. These figures must come down for ambitious climate adaptation.
Keeping ourselves comfortable in the home, via heating or cooling, is all to do with operational energy, but then there is embodied energy, which is the amount of embodied carbon in the material used in buildings. “The industry and the government haven’t addressed embodied energy as much to date,” says Harris. We can talk as much as we like about net zero, but sometimes when people say ‘this will be a net zero building’, actually, they’re only talking about the operational side of it – the building ‘in use’. They’re not talking about the materials that go into it”.
According to Harris, the embodied energy it takes to make petrochemical-based insulation, or concrete – which has high cement and non-recycled aggregate content – is “much bigger and more damaging”. Embodied energy is not currently regulated, but there the industry has proposed a new building regulation – ‘Part Z’ to address this. The problem, says Harris, is, as with most building regulations, they are at a minimum standard and developers lobby to keep them as soft as possible to avoid higher overheads. She suggests tougher legislation and ensuring the minimum standard required is “robust”.
Like Harris, Anderson also emphasises that the greatest form of climate adaptation is mitigation, which is why reducing consumption should be at the heart of everything. “There’s a certain amount of change locked in because of the carbon emissions and ecological damage we’ve done. Fundamentally, we need bold and ambitious action to avoid the more severe impacts,” he says. After all, innovative design can only do so much if an unmitigated climate crisis leads to an uninhabitable, hothouse Britain.