One thing for sure: Adapting to climate change

Species often evolve most quickly when under stress: a change in the environment forces adaptive improvements and only the fittest survive. Much the same could be said for the built environment. Design imperatives ushered in by the threat of global climate change have driven rapid advances in quality, so in many parts of the world buildings are now more airtight, better insulated, better cooled, less wasteful of materials and generally more efficient than ever before. Had the need to reduce carbon dioxide (CO₂) emissions not existed, it might have been useful, as a design challenge, to have invented it.

But this is only the first phase of what is proving to be a quantum leap in building design. Climate change is already occurring and it will continue to happen over the coming century and beyond. It is not enough that building construction and operation should attempt to mitigate CO₂ production: the built environment must also adapt to survive the new climate, and allow society to thrive in whatever conditions prevail.

We do, of course, have a general idea of what to prepare for. As summarized in the fifth assessment report from the UN Intergovernmental Panel on Climate Change (IPCC), “In urban areas climate change is projected to increase risks for people, assets, economies and ecosystems, including risks from heat stress, storms and extreme precipitation, inland and coastal flooding, landslides, air pollution, drought, water scarcity, sea level rise and storm surges.” This statement was communicated with “very high confidence” — the highest level of certainty employed by the IPCC.

The average global temperature is now 1°C higher than in the pre-industrial era, and we are already witnessing the consequences in the form of more extreme weather, rising sea levels and diminishing Arctic sea ice. In 2015, world leaders from 196 countries signed the Paris Agreement, committing to keep the temperature increase to “well below” 2°C and to working towards a lower threshold of 1.5°C. As they prepare to reconvene in December 2018, the IPCC has published its most strongly worded report yet, urging that 1.5°C should be seen as the maximum and outlining the significantly greater risks to people and the natural environment that would accompany a 2°C rise. The difference made by half a degree came as a “revelation” to the 91 authors of the report, who reviewed more than 6,000 studies.

According to the IPCC, there are just 12 years left to limit catastrophic climate change. But even if this very ambitious target is met, it still means the average global temperature will be half a degree higher than it is today. This represents a vast amount of extra energy in the world’s weather systems, resulting in a formidable range of negative impacts.

If the target is missed — and many experts now regard a 2°C rise as all but inevitable — the consequences for life as we know it will be severe. US-based research organization Climate Central forecasts that with a 2°C rise, homes occupied by 160 million people globally would be inundated by sea level rises, while a 4°C rise would result in the displacement of 600 million people, equivalent to the entire population of North America.

The future looks uncertain — doubly so given that the many and varied effects of climate change will impact on different areas of the globe in different ways. Furthermore, there is little agreement on when various future scenarios may come to pass. Having already been proven inaccurate by the passage of time, forecasters have stepped back from predicting changes by a certain date and instead tend to focus on what will happen when a certain temperature level is breached.

The trouble with change

For the architects, engineers and developers who shape the future of the built environment, this is awkward. We know that our designs must be resilient to change, but since we cannot know the extent and timing of this change, there is a risk that our solutions may be under-designed, over-designed or just plain wrong.

“It’s true we are dealing with a great deal of uncertainty,” acknowledges David Symons, global leader of WSP’s Future Ready innovation programme. “But if we take the view that it’s all too difficult and we don’t do anything, we will end up with suboptimal design. There is no doubt that climate change will be a huge issue for designers, for cities, for entire populations, so burying our heads in the sand will result in the worst of all worlds.”

Responding to this uncertainty is as important as planning for the future. Many projects, particularly infrastructure, have long design lives of over 100 years, says Symons: “Even with the best information, there is massive uncertainty over sea level and storm activity over that period.” On a recent project to upgrade a coastal railway embankment near Poole in the UK, WSP advised that the design life be reduced from 110 to 35 years. “It’s much less expensive in capital cost, and the intervening time can be used to assess what’s best to do next.”

On other projects, a shorter design life is not the answer. Sometimes the chosen solution is to build in flexibility for the future, as on the proposed Crossrail 2 underground line for London. “We expect London to be hotter,” says Symons, “but we can’t know how much or quite how that will impact the underground. So we don’t build in huge air-conditioning systems now. Rather, we leave space for vents and plant that can be fitted later as necessary.”

Adding empty plant rooms and shortening design lives requires a certain change in mind-set for designers trained to think about space efficiency, or accustomed to longer-lasting designs representing best value for money. The concept of resilience throws up many more challenges to contemporary thinking — not least that some measures taken in the name of climate change mitigation might not serve the need to adapt to new conditions.

Sweden has led the world on making buildings that are efficient to heat, greatly reducing energy demand in winter by improving airtightness and insulation. But Håkan Nilsson, consultant building physicist with WSP in Stockholm, says that it is now experiencing unprecedented problems as summers become hotter. “Already a lot of these very airtight and heavily insulated buildings are overheating badly, with internal temperatures way beyond 30°C. And because our weather is also wetter, mould is becoming a more common problem.”

The solutions for new buildings are fairly straightforward, such as increasing ventilation and making better use of thermal mass to even out temperature differentials between night and day. “Shading too is vital,” adds Nilsson. “It can be done in a number of ways: deeper window reveals, using balconies to shade windows below them, or fitting brise-soleils. But people are still building airtight glass boxes with too much potential for solar gain. We cannot even retrofit many of our existing buildings with brise-soleils because it is not permitted by local planning regulations, which deem them too ugly or not in keeping with the architectural style. But to me a beautiful building is one that works for the people who use it.”

Learning from disaster

Regulatory change may be necessary, then, if designers are to make the fullest contribution to a resilient future. This is echoed by social scientist Vivienne Ivory, technical principal with WSP Opus in New Zealand and a researcher at the University of Otago specializing in public health and urban environments. Ivory led a study of how the city of Christchurch is recovering from its two recent earthquakes, which revealed much about how society responds to disaster. “Though this was not a climate-related event, the destruction of homes and infrastructure is very much the kind of thing we are likely to see more of as extreme weather events such as cyclones and flooding become more frequent,” she points out.

The study found that different parts of the city are recovering at different rates. For example, those areas where it was possible to walk or cycle to shops or work are valued over those relying on cars. “One of the things that made a big difference was space,“ says Ivory. “Parks and squares became places where people came together and engaged with recovery. Space enabled the creation of pop-up functions — to replace amenities that had been lost — and this worked on every scale. We even saw a spare bit of sidewalk where old chiller cabinets had been turned into a free book exchange, a temporary library. So space which had initially provided refuge when disaster struck then provided leverage to help the city recover socially.” Her conclusion was that city-wide resilience requires both local connectedness “and maybe some compromises on the rules about how public space is used”.

It so happens that space is also a particularly effective tool for creating resilience to flooding. “Cities contain large amounts of impermeable surfaces, and heavy rain can quickly overload existing storm water drainage”, says Enrico Isnenghi, a technical director and water management expert with WSP in London. “Green infrastructure in the public realm such as parks, playing fields and ponds or lakes can all provide vital space for water to pond or flow, storing it safely and away from critical buildings and infrastructure.”

Green infrastructure offers the additional benefits of increasing biodiversity, reducing the urban heat island effect and providing high-quality amenity for citizens to enjoy. “I think municipalities and other stakeholders sometimes miss a trick here,” says Isnenghi. “It doesn’t help that funding for flood protection is often not structured to allow these additional benefits to be taken into account.”

Few would dispute the advantages bestowed by ample open spaces and green infrastructure, but land in cities is subject to fierce competition from many uses. Most of the world’s metropolises are becoming more densely populated and will have to make do with less undeveloped space rather than more. This is another issue where mitigation and adaptation seem to be pitted against one another. “The thing is, there are good reasons to densify a city,” says Iain White, professor of environmental planning at the University of Waikato in New Zealand and a specialist in risk and resilience. “It makes for more efficient land use, transport, utility distribution, plenty of positives to do with mitigating climate change. And policymakers will always be under pressure to use ‘spare’ space for other things, like social housing. But the reality is that you either make space for water above ground or below ground in pipes or storage — and a playing field is usually much cheaper than building new hard infrastructure.”

White remains optimistic that these conflicting pressures can be resolved, by combining ingenious design with a little regulatory tweaking. “You’ve heard of the zero-carbon house. You can have a zero-runoff house, even in a densely populated city. You can have measures like permeable paving, or you can delay the rain flow by using underground storage tanks or green roofs to slow the release of water into the existing drainage system and help it to cope with extreme precipitation. Because this is not standard design or part of a strategic perspective across a city, you need to embed it within the planning process.”

A persuasive business case

No discussion of climate adaptation makes sense without considering the price. After all, it is not that we don’t currently have the know-how and technology to heat, cool, store water and protect against storms and high seas. Symons points out that the world already provides handy climate analogues. For example, the interactive Analogues Explorer tool developed by Climate Change in Australia shows that under a high-emissions scenario, Sydney’s temperate climate could be closer to that of subtropical Brisbane by the end of the century. A 2017 paper in the International Journal of Climate Change Strategies and Management explored climate analogues throughout Europe, finding that Berlin’s climate will shift progressively south-westwards to reach northern Spain by the end of the 21st century. “Knowing that the climate in north Spain is much hotter and drier, with more frequent and intense heat waves, residents of Berlin could easily apprehend the magnitude of climate change and immediately envision the type of future climatic conditions they will have to cope with,” said authors Guillaume Rohat, Stéphane Goyette and Johannes Flacke.

The bigger challenge is the business case, though there is a persuasive one to be made, argues Nilsson. “People care about losing money more than anything else,” he says. “I find that when you explain the wellness argument — when you point out that if your office gets too hot you are not going to attract the best people to work there and your very expensive workforce is going to be 10% less productive — then people listen. They suddenly see that adaptation measures can be very cost-effective and actually deliver competitive advantage.”

As businesses and governments develop their own responses to climate change, the notion of competitive advantage is likely to figure more prominently. “Investors don’t like risk,” says Symons, “they do like resilience. So it makes sense for an environmental regulation body, say, to talk about a country gaining economic advantage from being water resilient.”

Politicians and administrators are beginning to understand and respond to this approach. For example, WSP is advising an Irish county that intends to use its preparedness against climate risks as a differentiator to draw inward investment. Symons believes that money will be attracted to resilience at every level: “If you are investing in a property, you don’t want it to flood or to become unlettable because it is overheating. You want it to be safe and successful. It’s important to realize that climate change is not just an issue for governments. There is a lot that corporations could and should be doing to make themselves resilient.”

Businesses that start to assess their own risk will find they have embarked upon a surprisingly broad examination. After securing the safety and comfort of their premises, and the security of their power, data and other utility functions, they might then move on to consider wider issues such as the ability of their workforce to commute, the security of their supply chains, and the risks posed by climate change to both investors and customers.

“It is easy for climate risk to sound rather apocalyptic,” says Symons. “But with change comes opportunity. And those who understand the change and respond positively will be the ones to reap the rewards.”