Climate change risk and decision-making

1. INTRODUCTION

There is no doubt that the currently changing climate and the progressive shift to a hotter world with a more volatile weather system poses a series of very substantial risks to the environment, both natural and built; to those who depend on it for their lives; and to the systems and structures they construct to ensure its quality and endurance. This includes humans and the buildings, settlements and infrastructure they have already built and will need to continue to build. That these risks are in large part due to the carbon emitted into the atmosphere during the construction and operation of the built environment is also well attested (Cooper 2026), but it is not the subject of the special issue, and need not be detailed further here, except to add that there is a natural degree of moral responsibility on the part of built-environment professions to address the problem of climate risk effectively without causing further harm, insomuch as it can be avoided.

The built environment forms a major part of the worldwide economic and social asset base, and the level of potential harm to it from climate change impacts, if even partly realised, will cause immense damage to individuals, communities, infrastructure and entire ecosystems as well as economies, government functions and future prosperity. This is already evident from the responses to and outcomes of climate-related disasters such as the recent glacier collapse in Tibet and subsequent flooding there and in Nepal. This places a substantial onus on everyone with responsibilities for the production, regulation and stewardship of the environment—including government (both local and national), commissioning bodies, owners and their professional and service-providing teams, as well as standard-setting, audit and oversight organisations—to ensure that risks are properly assessed and appropriate action taken in response.

At present it is not clear that this responsibility for climate-related risk assessment and action is adequately recognised, that the necessary skills have been developed or that it is even on the agenda of the many organisations and authorities that need to be treating climate risk with the level of seriousness it requires.

Climate risk comes with unique pressures. The ongoing changes to the global climate will, with a high degree of certainty, cause major alterations to the way we live, to the economic system and to the environment. These changes cannot be assessed solely by examining current data and experience, whatever the current trends.

The impacts of climate change are already tangible and well evidenced, especially in more vulnerable parts of the world. The underlying risk factors are also well known; higher and less stable temperatures, melting icecaps and rising water levels, increased and more frequent floods and droughts, higher wildfire risks, shifting ecological zones, greater exposure to pests and disease vectors, etc. These then spill over into societal risks, e.g. livelihoods, inequality, conflict and migration (O’Neill et al. 2022). The inherent uncertainty relates to when rather than if, as well as the potential for hazards to occur simultaneously or in close succession, compounding one another or triggering further harmful events.

The societal risks will affect those both least responsible for and most vulnerable to climate change. This raises issues of moral responsibility, climate justice (Klinsky & Mavrogianni 2020) and how to ensure that response to risk serves the interests not only of those with the means and ability to look after themselves, but also of those who generally lack the agency to influence decision-making. This matter requires wider political and social debate and potentially reimagining (Castán Broto et al. 2024), but more specifically in the context of this special issue for the development of policies, ethical frameworks, action programmes, toolkits and guidance for promulgation by governments, planning and regulatory authorities, sector organisations, and professional bodies.

2. RESPONSE AND RESPONSIBILITY

Potential responses to climate risk fall into several categories beyond the most common: doing nothing and hoping for the best. These include the following:

• Avoidance

  Ensuring that a hazard is either blocked or sidestepped: this might include managed retreat from the likely location or occasion of the hazard.

• Resilience

  Ensuring that should a hazard occur, it has minimum impact and can be recovered from relatively straightforwardly, e.g. raising living accommodation above possible flood levels.

• Adaptation

  Modifying behaviour or the physical surroundings to reduce the impact of the hazard, e.g. installing planting in urban areas to provide nature-based solutions (NBS).

• Insurance

  Taking financial and other measures in advance to enable recovery.

• Acceptance

  Acknowledging the risk and being prepared to rebuild and recover if and when the hazard occurs.

This list raises the question of who should be responsible for identifying and articulating climate change risks associated with the built environment, and particularly those associated with a specific project, asset or location; and for making decisions involving those risks? Logically the response to this should not be dissimilar as to who should take responsibility for other significant issues affecting the built environment, including health and safety, safety and wellbeing in occupation and use, and financial and sustainability concerns. There may be differences in scale and because the prime drivers of climate change risk are likely to be well beyond the boundaries and the control of individual project owners or even national governments, but the principle remains the same. Responsibility and duty of care for raising issues and taking relevant decisions will lie with those who have the relevant expertise, ethical obligation and authority. This undoubtedly includes built-environment professionals in the widest sense, but does not resolve the aligned and potentially more critical question of where accountability should and will lie for the failure to act appropriately, whether by commission or omission, in the face of clearly and widely communicated climate risk factors.

How might those professionals procuring, producing, managing and modifying built environment assets be able to understand and assess climate and other risks: to discuss, evaluate, prioritise and take relevant responsibility in order to determine, recommend and implement appropriate actions? Doing so potentially means acquiring an additional professional skill and expertise set in order to assemble the evidence, navigate the concepts and techniques of risk assessment, and avoid the many misperceptions and unconscious biases that afflict decision-making and set traps for the unwary. This then needs to be allied with the professional responsibility to communicate, offer guidance, and provide advice and solutions as and when necessary.

There is a clear duty on the part of professionals dealing with the built environment to look forward and anticipate future conditions in their work, but the rapid change in global and local climate conditions makes the challenge of doing so all the greater and raises a series of questions:

• Will, and at what pace, professionals, their firms and their various professional organisations be prepared and able to embrace the acquisition of new capabilities and responsibilities?

• How will these responsibilities be defined, assigned and overseen?

• Where should accountability lie and be apportioned for perceived failures to raise concerns about or adequately prepare for future climate conditions?

• What coordination of decision-making would be needed beyond an individual project to address larger scale issues for a specific neighbourhood or region, building type or the wider building stock?

This special issue explores multiple aspects of this critical, if relatively poorly discussed, subject with the individual papers illustrating, in depth, some of the many dimensions of climate risk.

3. THE DIMENSIONS OF RISK

Traditional assessments of risk have couched it as the product of probability and impact, but following the extensive work done on climate change risk spearheaded by the Intergovernmental Panel on Climate Change (IPCC) in its Assessment Reports (ARs) in particular, more elaborate framings and definitions have been developed—a process that is ongoing (Simpson et al. 2021). Risk assessment approaches for urban settings are further discussed in this special issue by Rigoni et al. in their paper on neighbourhood-scale climate risk adaption.

In the IPCC’s AR6, climate change risk determinants are defined as a combination of the nature of the hazard, the vulnerability of the subject and the degree of exposure to the hazard. These are then further augmented by the ability and capacity to respond to hazards and the value ascribed to any potential loss (Cardona et al. 2012). The specific risks generated by this analysis are then entered into a more complex typology that assesses how they interact with other risks, in particular in compound or emergent risks. These categories are currently being expanded for AR7 (IPCC 2026) to also include cascading, reversible, irreversible and residual risks. These classifications are discussed further below.

• A hazard is both the potentially harmful event, and the potential consequences should it occur, including an assessment of the probability or frequency of its occurrence—effectively the old definition of risk. Multiple categories of hazard relate to climate change—both first order: e.g. rising temperatures, more extreme weather conditions and flooding; and second order: temporary overheating, physical damage to buildings or the need to evacuate or even migrate.

• Vulnerability represents the extent of harm that a hazard will cause in a particular instance and will vary from both case to case as well as from hazard to hazard. This might be as a result of sensitivity to change or from pre-existing fragility, isolation, lack of economic headroom and elasticity, as well as cultural, social and other issues. As the IPCC points out ‘vulnerability is, among other things, the result of a lack of capacity’ (Cardona et al. 2012: 72). A vulnerability metric will include the other element of probability: the likelihood that harm will be caused by a particular event. The IPCC in AR6 (Cardona et al. 2012) included the ability to respond to mitigate the impact of hazards within its definition of vulnerability, but it is now thought more useful to consider these two aspects separately.

• Exposure relates more closely to geographical locations and the presence there of populations or ecosystems capable of being harmed. This may be extremely local as well as regional. Microclimates in an urban environment can vary from street to street as a result of physical building configuration and variation of surfaces as well as to the presence of vegetation, water and other factors. Similarly, a particular valley in a landscape may be exposed to the possibility of flash floods or landslides in a way that neighbouring areas are not.

• Response allows for the ability to deal with a hazard through relevant preparation or available and ready resource and training, so as to minimise harm. It closely relates to economic and technical capacity, as well as to social stability and accessibility, but it should be noted that almost any level of resource is capable of being overwhelmed when multiple events need to be contended with simultaneously.

• Finally the perceived value of the harm that can be caused can vary between locations and cultures. For example, the value of a heritage building in one area may be high, while it is low elsewhere. This can depend on many factors, including its relative rarity, a longstanding relationship with a population or the particular value system of a culture.

The product of these five factors provides an assessment, however rough and ready, of the risk of harm of events on an independent basis, a process that has been in place in the insurance, investment, infrastructure, and performance and safety sectors for a considerable time, but does not factor in their place in a wider system, or consider the possibility of complex interdependencies with other confounding events. The potential for linkages between individual risks must be accounted for in any risk planning and there are several recognised, if ever expanding, typologies for complex risk analysis (Simpson et al. 2021):

• Compound risk

  Where risks do not just occur at the same time but work together to multiply harms, e.g. a drought may not just damage the natural environment and cause subsidence to buildings, but can also create the conditions for wildfires to spread.

• Cascading or networked risk

  Where one event can actively trigger another and cause a chain reaction of consequences, e.g. a flood may cause power outages as electrical substations are put out of action by the rising waters. A worst case may be the crossing of a tipping point, where cascading risk sets off an unstoppable sequence of events.

• Aggregate or accumulating risk

  Often relating to gradual overloading or deterioration until the point of failure, e.g. physical infrastructure that is not adequately repaired or upgraded, particularly when environmental conditions or usage have changed, such as a bridge, increasingly worn away by more frequent and extreme climate events, but also expected to carry a heavier and greater number of vehicles, eventually leading to its collapse.

• Irreversible risk (and its counter: reversible risk)

  Events that causes permanent damage and may be considered far more harmful than damage that can, however gradually, be repaired, e.g. loss of ancient natural or historic environments.

• Residual risk

  The remaining risk after all other relevant measures have been applied.

Several studies and reports, including the IPCC’s ARs, the UK Government’s Chronic Risks Analysis (HM Government 2025) and the Independent Assessment of UK Climate Risk, now in its fourth edition (CCRA4) (CCC 2026), attempt to give structure and values to both individual risks and also their potential interactions and system effects.

Questions that emerge from the complexity inherent in risk assessment include the following:

• What skills and methods already exist, especially in other fields, that can be suitably adapted to climate risk assessment in the built environment?

• Do new approaches to risk assessment need to be developed if they do not?

• What levels of objectivity and independence are required and can be achieved in making risk assessments?

• How should a risk assessment be meaningfully translated into recommendations for action and prioritisation?

• To what extent should capability in climate risk assessment be a universal attribute of all built-environment professionals, or should it be a specialist skill set for specifically trained and accredited practitioners?

• What responsibility, and with it accountability (and over what period), should built-environment professionals accept for climate risk in relation to their advice and project performance? Will they be able to obtain appropriate insurance cover or protection if they do so?

• Is there the capacity in the system to adequately train and retrain built-environment professionals on the subject of assessing and dealing with climate risk?

4. THE NEED TO ADDRESS CLIMATE RISK

Dealing with the idea of long-term risk is by its nature complex and difficult: the events under consideration have not yet happened and are inherently uncertain. Concerns can easily be ignored or parked when there is so much else that that is already known and demanding urgent attention. Yet we are only moving forward into the future and almost everyone involved in the built and natural environment sector is, by the very nature of their work, looking at least to the medium term (15–30 years) and has a personal interest in the fate of their efforts over that period, if not for far longer.

In order to plan, build and appropriately invest for the future it is necessary to project forwards, to build scenarios from available calculations and ways of life elsewhere on the planet, and to assess both probable and possible conditions, including worst-case forecasts made by meteorologists and others.

The range of potential risks is almost infinite and it is not feasible or even practicable to prepare for and protect against them all. Choices and strategies are necessary to ensure that a limited capability for investment in effective measures is deployed well. This is where long-term risk assessments are most urgently required and why almost all activities in the built and natural environment sector need them to underlie decision-making.

An effective risk assessment will allow decisions on appropriate preparations for changing climate conditions and impacts to be made well in advance. This may be a combination of actions in the short, medium and long terms, but also ensuring that adaptable systems are put in place from the outset, capable of readily accepting change when it becomes affordable or necessary.

Addressing climate risk is likely to require greater upfront preparation and possibly higher initial investment than current practice demands. This is only worthwhile and arguable for if it can be demonstrated to lead to increased benefits over the lifetime of built facilities. Such benefits may include greater safety, security, reassurance, wellbeing, sustainability, asset value, reductions in running costs and durability. Historically in the finance sector, understanding and addressing risk has led to the development of a series of essential tools for managing uncertainty; including limited liability companies, insurance and even the establishment of fire brigades, as well as better and more consistent standards and regulations. Taking a risk-based approach to the challenges of the built and natural environment sector should pay similar dividends, but only if it is adopted with appropriate skill, understanding and expertise.

5. ASSESSING RISK

Taking a long-term risk-based approach means being forward-looking while remaining very aware of lessons from the past. It requires both imaginative reach and the ability to accurately calculate probabilities, rather than a reliance on instincts beset by recognised, if difficult to avoid, cognitive biases and informational noise.

Guidance on carrying out risk assessments is available from multiple sources, of which two examples are highlighted here. In an internationally authored paper, King et al. (2015) make six recommendations:

• Assess risks in relation to objectives, or interests. Start from an understanding of what it is that we wish to avoid; then assess its likelihood.

• Identify the biggest risks. Focus on finding out more about worst-case scenarios in relation to long-term changes, as well as short-term events.

• Consider the full range of probabilities, bearing in mind that a very low probability may correspond to a very high risk if the impact is catastrophic.

• Use the best available information, whether this is proven science or expert judgment. A best estimate is usually better than no estimate at all.

• Take a holistic view. Assess systemic risks, as well as direct risks. Assess risks across the full range of space and time affected by the relevant decisions.

• Be explicit about value judgments. Recognise that they are essentially subjective, and present them transparently so that they can be subject to public debate.

An alternative set of Principles for Good Practice in preparing a risk assessment was created by the Royal Academy of Engineering (2022):

• Ensure a joined-up approach.

• Encourage participation and communicate clearly.

• Focus on impact.

• Explore interdependencies.

• Consider a range of scenarios.

• Embed new data and metrics.

• Review based on need.

Combining these: assessments should be made on the basis of the widest range of information and studies available, with a clear view of the relevant evidential bases. Taking multiple viewpoints into consideration is important for the best possible results, given that while no one will have perfect information; a diversity of experience, local knowledge and technical expertise will generate a greater range of potential futures than a homogenous approach. These can then be developed into a set of varied scenarios for further exploration and testing. Scenario-building and analysis is now a familiar and well-developed means of interrogating the future with both formal and informal methodologies available for use.

Narrative backcasting, involving developing sequences of steps that lead to possible futures (sdt n.d.). can also provide useful understanding of how events might occur in practice and help with the assessment of likelihoods and potential avoidance mechanisms, as well as highlighting particular vulnerabilities and exposures. It may be easier to spot dangerous interdependencies from the perspective of the future looking back and using imaginative hindsight than looking forward at what may seem an unlikely set of coincidences.

Risk assessments should be supported by detailed modelling of weather and other climate-related conditions, whether on a regional or a hyper-local scale. Such projections are widely available, but will often only provide generalised or averaged-out forecasts with estimates of statistical error and eliminate much of the noise and variability that occurs in real-life conditions. For risk assessments it is the extreme and occasional that are most dangerous. Plausible worst-case scenarios are therefore an important consideration, especially given the life-cycle of an asset or environment for which it may be necessary to prepare. Information on average changes to climate conditions may be useless when it is the extreme storm surges that overtop flood defences or the exceptional heatwaves that cause deaths in otherwise comfortable apartments. Worst-case scenarios should also allow, almost by default, for compound and/or cascading risks.

Assessments should include clear recognition and appraisals of those risks it is important to avoid, as well as those whose impacts can be reduced or readily recovered from. Risks to be avoided, by their nature, may not require the extent of analysis needed elsewhere; as a definitive decision can cut straight through to the measures required to achieve that, as well as any possible unintended consequences, such as the tendency not to eliminate risk, but to transfer it elsewhere. For example, selection of a nature-based cooling system that does not rely on an uninterrupted electrical supply to function avoids the risk of uninhabitability of a building during a power outage.

With any risk there are also potential opportunities, and these should be addressed together in any assessment. An investment in resilience measures may create the possibility of achieving other goods with little extra resource or make an initiative investable for other possible gains.

Risk assessments are rarely one-offs and need to be carried out regularly and systematically, especially as risk profiles change and there are new or emergent risks to account for.

6. MANAGING RISK

Risk can be managed either before or after an event occurs. Insurance can be taken out in advance or other preparations put in place in the eventuality of predicted harms occurring. A property or a landscape can be made sufficiently durable and robust prior to an event, possibly incrementally, or it can be repaired once the damage has been done—or often a combination of the two. But whichever way round, risk can only be managed effectively if it has been identified, assessed and planned for.

Risk management, if taken seriously, is a specific responsibility requiring its own workflow, budget and resources. It needs to be owned. As such it takes on many of the attributes of other areas of property and business management, including preparation, communication, planning and training. It should be noted that risks allowed for and ‘managed’ using a single or limited rage of metrics, e.g. purely financial or geographically specific ones, may allow other harms to occur elsewhere, e.g. to vulnerable populations or to environments downstream of flood control measures.

Strategies for risk management include avoidance, adaptation, resilience, autonomous organisation—e.g. swarm planning (Roggema 2012) and anti-fragility (Taleb 2012)—preparedness and managed retreat.

The wider impacts of climate change may now be unavoidable across the world, but on a smaller scale an avoidance strategy for the built environment might involve decisions about where to build: away from potential flood zones, in areas with good ventilation or lesser dangers of fire, close to support facilities, etc. Much of this is long familiar to city developers and planners, who have always ensured the more salubrious residential areas are upwind and upriver of polluting industries. It is the parameters that have changed, not the basic principles. Another approach might involve investment in NBS to provide sufficient eco-services, such as shade, air filtration, water retention, soil health and ground stabilisation, to enable a location to retain or recover its liveability, at least in the immediate term. Consideration is needed to ensure that NBS are appropriate to projected future conditions.

Adaptation, on the other hand, means accepting a changed environment and responding to its challenges through changes to planning strategies, designs, layouts, materials, technologies, etc. with the intention of maintaining sufficient levels of safety, functionality and comfort. Examples for temperature and overheating control might range from passive measures such as increased shading, cross-ventilation, use of thermal mass and night-time purging, to active alternatives such as mechanical cooling, up to and including air-conditioning. Similar adaptive measures are conceivable in the face of increased flooding, rainfall, drought, fire risk, etc., although they may not necessarily be universally palatable or affordable, and in some cases may exacerbate the problem elsewhere through, e.g., the uncontrolled dumping of heat into city streets. The example of existing building types and systems in tropical climates suggests many lessons for adaptation in current temperate zones, but the future of the tropical zones themselves looks increasingly bleak.

When adaptation and resilience measures are not enough, preparedness for short-term extreme conditions may be required. This might take the form of rehearsed emergency protocols, cool or warm spaces for sheltering citizens, emergency flood defences, or stocks of water, food or fuel for distribution when normal supplies fail.

The problem with adaptive, resilience and, above all, emergency preparedness measures is that they may only delay the inevitable. Eventually the defences will be overcome, or the night air temperatures will be too warm to provide any cooling function. They can only go so far or last so long. At that point anticipatory action in the form of managed retreat may be inevitable and effective risk assessment should have ensured it is carried out sufficiently in advance to avoid harm to lives and livelihoods. Such action might include relocating whole towns or cities threatened by sea level rise (Ocean & Climate Platform 2025) or persistent subsidence as with Jakarta, Indonesia (Batubara et al. 2023).

7. PROFESSIONAL RESPONSE AND RESPONSIBILITIES

The role of professionals working in the built and environment sector (as individuals, firms, institutions) in a period of climate change, whether in design, construction, property management, finance or insurance, becomes both essential and critical. Individuals and firms need the skills to identify and assess potential risks; develop, present and evaluate possible options and solutions; and to design, make arguments for and implement effective measures. This will involve developing and using a shared language, putting uncertainty into comparable numbers, and growing a collaborative community of practitioners to exchange and optimise approaches. The apportionment of capabilities, skills and responsibilities is yet to be discussed and agreed. It will certainly vary between countries and perhaps also between different types of projects.

Fortunately for a sector relatively new to the challenge of long-term risk, others have been working on the problem of describing and defining uncertainty for far longer, notably in fields such as gambling, probability theory, weather forecasting, climate modelling, investment and insurance. It will be important to learn their lessons and as far as possible use their tools and techniques, and if for the non-mathematically minded, these often veer into hard statistical analysis, they are also very susceptible to graphic explication and exploration.

Given the uncertainty, forecasting is an imprecise science and it is necessary to use the best, or sometimes the only, data available, with a view to later upgrading. Straightforward probabilistic approaches should be a starting point, using graphic techniques such as frequency trees, scatter plots and error bars to explore what the data can reveal. For more in-depth analysis a familiarity with Bayes’ theorem, used to update prior beliefs with additional evidence, may be required. Above all, it is essential that built-environment professionals become ‘risk-literate’, able to approach assessments of uncertainty and risk factors and potential outcomes with confidence and sufficient detachment to propose evidence-backed ways forward.

The education system will need to adapt to ensure that future professionals are properly risk-literate and adequately trained to cope with multiple aspects of uncertainty, especially in how to make sense of available and imperfect data and evidence in order to guide decision-making and effective allocation of resources. This will equally apply to the need to re-equip existing professionals with analysis and assessment capabilities as the climate breakdown increases the level of challenge they face.

To aid consistency in the use of words that define uncertainties, the IPCC (Mastrandrea et al. 2010) issued a guidance note for describing levels of likelihood. These terms (Table 1) should be used as accurately as possible and be qualified by the expected frequency of the events described.

With a focus on worst and rare case events, the emphasis will need to be on events in the very unlikely category and above at least 1 SD or possibly 2 SD (standard deviations) from the mean in the long tail of a distribution. Data on previous and emerging climatic conditions can predict what can happen at the extremes, even as the mean conditions based on five- or 10-year averages gradually shift to ever more challenging positions.

Further and conditional probability assessments can be applied to deal with the issue of compound risk and show how likely is it that two events will occur together? Will the first occurrence influence the chance of the second or might they both share a joint cause in a different event altogether?

Being able to cope with such calculations, even if it is only to understand them and to be able explain the implications to policy- and decision-makers as well as society as a whole, should be a core skill and responsibility of built and natural environment professionals and therefore the education and training system. Professionals will need not only to be able to tackle challenging environmental problems, but also to justify and communicate why it may be necessary to provide potentially disruptive solutions to deal with climate conditions that do not yet exist.

8. TAKING DECISIONS

The responsibility to take action will not entirely be in the built-environment professionals’ court, however much they provide the analysis, arguments for investment and potential solutions. There is a major role and responsibility for project owners, commissioning organisations, governments and local, regional and statutory authorities, especially when the best solutions transcend immediate ownership or disciplinary boundaries.

Undoubtedly, while much of the strategic work for preparation and making major investment decisions on substantial infrastructure needs to happen at national or state government level, the local and community scale will be where any action will take place and resilience emerge. Imposed ‘one-size-fits-all’ solutions are more than likely to fail on exposure to local conditions and circumstances. Good and responsive governance is critical, but so is foresight and preparation. Effective and functioning democracy able to channel information, opinion, understanding, concern, resources and timely decision-making up and down between layers of government is essential, both to achieve consent on long-term preparatory and protective measures at one end of the scale and to be able to act fast in emergencies at the other.

Alongside policy- and decision-makers and community actors, professionals acting in the greater public interest have an important role as mediators and facilitators in ensuring the complex interfaces run as well as possible, through providing appropriate information and insights, making judgements when called upon to do so and working to maintain and steer systems as necessary. This may be as consequential a role, with as much agency, as that of making the decisions and providing the investment.

9. SPECIAL ISSUE CONTENT

The papers and commentaries produced for this special issue are listed in Table 1. They do not engage directly with many of the components of the highly complicated problem definition for risk versus responsibility set out above. Instead, despite looking in different directions, they all converge on governance issues.

The three research papers examine a variety of locations—stretching across continents from Africa to South America—to considering neighbourhoods globally. They each focus on different spatial scales, from large urban municipalities—the metropolitan sub-region of São Paulo, Brazil (Nastari Fernandes et al.) to informal African settlements (Buyana & Sseviiri), through to individual neighbourhoods (Rigoni et al.). Despite these differences, there is a clear convergence in the limited number of climate-related risks they address. Nastari Fernandes et al. mention severe and extreme weather events such as flooding and landslides; Rigoni et al. consider heatwaves, floods and coastal hazards; and Buyana & Sseviiri discuss flood-related risks. But these climate-related risks are not the primary concerns addressed in these papers. Their predominate focus of attention is on social problems (or failings) rather than environmental ones. Instead, they engage with the inadequacy of governance arrangements currently in place for making decisions to deal with the impacts of climate change, whether between national and local (government) organisations, or between these and their local electorates, or in local communities.

Nastari Fernandes et al. concentrate on how urban populations have uneven exposure and vulnerability to changes driven by climate change. They examine policies made by federal government and the municipal administrators responsible for implementing them. Here local governments are expected to act as first responders in situations of risk. However, the authors note that implementing these responsibilities receives limited routine (financial) support or coordination from federal government in Brazil. As a result, they conclude that municipal climate-risk governance is not executing promotion of federal mandates. Without coordination mechanisms and support for local capacity, they argue, climate change action is unlikely to produce the structural changes required to effectively tackle the unequal distribution of vulnerability across municipalities. The authors recommend that policymakers should focus on assigning responsibilities and creating enabling conditions for implementation, including more stable support, stronger coordination mechanisms and greater sensitivity to territorial inequalities between municipalities.

Buyana & Sseviiri examine the governance of flood-related risks in informal settlements in Africa. They argue that maladapted responses often occur because of narrowly framed structural engineering plans for infrastructures (e.g. roads, drainage and sewage systems). Such narrow problem definitions give rise to adaptation governance risks. They identify community-based organisations, because of their local knowledge, as the primary category of actors that should be tasked with driving inclusive, participatory planning for tackling climate change. They recommend that the critical role of informal urban settlements in building climate-resilient urban futures needs to be recognised, particularly in cities of the Global South if interventions are to be successful in reducing emissions, creating clean urban spaces, boosting household incomes and mitigating waterborne health risks during floods. The authors note that while standard understanding of flood-related risk is a function of frequency, exposure and vulnerability, the places and populations affected by flood-related risks in informal urban settings are not solely attributable to climatic conditions. In practice, they are deeply rooted in what the authors describe as a complex convergence of historical social inequities, different layers and networks of political engagement, and economic and environmental factors.

Rigoni et al. seek to set up a new approach to decision-making about adapting to climate risk. This needs to be undertaken at the neighbourhood scale; and it needs to encompass not just environmental, spatial and social dimensions, such as heatwaves, floods and coastal hazards, but their interaction with local social, ecological and infrastructural variations as well. The authors argue that policymakers and planners need to be equipped with diagnostic strategies capable of targeting context-specific interventions. These should cover infrastructure upgrades, social networks, governance adjustments and avoid one-size-fits-all approaches. They encourage design practitioners to embed resilience into neighbourhood planning/regeneration by aligning this with local capacities. Doing so requires moving away from both city-level adaptive capacity frameworks and building-level adaptation strategies to assessing neighbourhoods as adaptive systems. This will, the authors judge, enable targeted, context-sensitive interventions capable of combining spatial/environmental data with community insights at the neighbourhood scale, capable of encompassing interacting social–ecological–technological–governance dimensions. Accordingly, the authors recommend positioning neighbourhoods as meso-scale interaction/feedback hubs able to make nuanced assessments. Employing such hubs should lead to informed anticipation and locally grounded interventions, using expanding systemic yet context-sensitive policy/practice toolkits for bring about resilient futures.

The four commentaries listed next in Table 2 were commissioned to support the three papers in the special issue. Baker considers the challenges facing local authorities in identifying and managing climate risks, asking: how do we get the leadership, skills, capacity and meaningful action needed? In the UK, climate adaptation responsibilities are fragmented between national government and local authorities. What is needed, he concludes, is a statutory duty to be placed on local authorities containing a strategic priority, with clear roles and responsibilities identified between government agencies. Most local authorities are characterised as still needing to undertake a climate risk assessment of their local area and services. The author recommends local authorities assemble an evidence base that will enable them to plan proactive adaptation rather than simply reactive emergency responses.

Greenham & Ferranti focus their commentary on chronic climate risks to urban infrastructures and to individual public/private properties. Their list of these chronic risks includes not just extreme heat, wind and rainfall, changing seasonality, sea level rise, storm damage, coastal erosion, drought, water scarcity, subsidence, reduced green infrastructure, but also economic and social disruption. Because of the length of this list, no single organisation can manage all aspects of climate resilience. Instead, shared responsibility across multiple actors in central, regional and local government and beyond. In the case of London, these actors include the UK government and its National Risk Register, the Climate Change Committee (CCC), the Environment Agency, the Greater London Authority (GLA), Thames Water, Transport for London (TfL), local authorities and their local resilience forums, highways teams, wastewater utility providers, port operators, property owners, residents, and users. Given the comprehensiveness of this list, the authors call for more integration of decision-making, e.g. by repairing the disconnection between national-level climate adaptation reporting cycle and local-level management of local infrastructure. They also recommend an increase leadership role for combined authorities in regional climate action via advocacy and regional capacity-building.

Robinson et al.’s commentary is focused on reimagining climate action, community engagement and professional responsibility. They identify the plethora of challenges facing cities for decision- and policymaking on multiple spatial scales and the wide range of actors that need to be involved in tackling these: city administrations (policy and decision-makers), community development professionals, local communities, residents. They note there is a lack of bottom-up, local community support for top-down climate change adaptation strategies. Typically city leaders ultimately make the decisions here, but to be most effective these should be based on a clear understanding of neighbourhood priorities and desires, and how these can be supported by city agendas. The authors identify community development professionals have critical responsibility here for knowledge co-production, providing a expertise about what climate mitigation and adaptation strategies can advance local efforts towards healthier, more equitable and resilient communities. They suggest that there is little evidence that information-based campaigns will achieve the level of support and engagement required to meet climate goals. Instead, they recommend focusing on activities that build trust and support actions that advance local community) agendas. The authors recommend that city administrations should link their climate goals explicitly to preexisting collective agendas of neighbourhood residents. Contributions from professional experts need to be situated in relation to community goals and development agendas, not just with government priorities, and should not be treated as the sole source of authoritative knowledge.

In the fourth commentary, Davies & Ellis look at professional ethics and the climate crisis. They do this from their positions within the UK’s Town and Country Planning Association, an organisation whose mission is:

to challenge, inspire and support people to create healthy, sustainable and resilient places that are fair for everyone.

The authors’ concern is for the UK built environment as whole. But their commentary specifically focuses on individual homes and flats with attention to flooding, overheating and fuel poverty. They identify a wide range of decision-makers as being involved here: the UK government, its CCC and Environment Agency, property developers, professional institutions, as well individual built-environment professionals. They note that UK developers bear no long-term financial responsibility for properties created. As a result, problems and remediation costs fall to owners, occupiers and the insurance industry. In their judgement, the UK’s current regulatory framework should be judged as not fit for purpose. As a result, professionals should take on the role of safeguarding public interests. But the question is whether professionals will step up and accept this responsibility. In their judgement, a new requirement needs to be added to professions’ ethical codes to ensure they do. These codes need to be amended to include a specific duty to ‘do no harm’.

The fifth commentary by Cooper explores questions of responsibility raised in the special issue by focusing on carbon emissions and mitigation. Two questions are explored: i) who is responsible for (causing) climate change and ii) who should be responsible for (trying to fix) it? Multiple claims and counterclaims are identified. So apportioning responsibility for mitigation to reduce GHG emissions from the built environment is no simple matter. The range of decision-makers implicated, the spatial scales at which to act, and the stages of the procurement and operation deemed significant—make identifying culprits and then targeting interventions a highly complex and difficult to implement process. Global responses will need to be grounded in what can work locally. New responsibilities arise for the wide range of built environment decision-makers: clients, professionals and their institutions, central and local government policy makers, product suppliers, financiers, insurers, etc. To aid further research, an overarching framework is needed to manage the complexity of responsibilities capable of capturing the variety of actors, time frames and spatial scales involved.

There are common characteristics to the papers and commentaries included in this special issue. Despite the varying locations they examine, the different spatial scales they address and the separate (but overlapping) focuses of their attention, all the authors are more concerned with social problems raised by attempting to tackle climate change than with dealing with climate-related risks themselves. And although they look in different directions, they have a shared point of convergence: the need for governance to control who makes decisions and so whose voices get heard. They also share a common diagnosis of what needs to be done. They all judge that the governance arrangements currently in place for making decisions about how to respond to the challenges imposed by climate change are defective and unlikely to prove successful. In aggregate, they advance a common remedy too. Decision-making needs to become more integrated by enrolling a wide range of top-down, middle-out and bottom-up actors—from national and local government and their agencies, through professionals and private sector organisations, to local communities. Localising decision-making is deemed particularly important here, the authors argue, if selected interventions are to be sufficiently grounded in local knowledge about the contexts in which they will have to work.

10. CONCLUSIONS

Whilst there is a growing body of knowledge covering both adaptation and resilience, the subject of long-term (also known as ‘chronic’) risk in the built environment sector is only thinly dealt with in the research literature, let alone on the curricula for current and future professionals. This leaves a wide field for research programmes, particularly in the translation of work already done in other sectors such as insurance, finance and health, but also, and increasingly, infrastructure. Professional bodies and companies also need to take the risk agenda and its accompanying tools and techniques on board as a critical skill and capability needed by their members and employees to thrive in times of uncertainty. Some key areas for development might include the following:

• Establishment of a common language with well-defined terms.

• Exploration of and familiarity with core risk concepts and assessment methods.

• Development of standard metrics and guidance, including a lifetime risk-value metric that factors in the costs and benefits of taking a long-term approach to predicted climate events.

• A cross-disciplinary competence framework for the understanding and assessment of risk.

• Cross-disciplinary risk-training modules.

• A centre for built environment risk studies.

• Case studies of both historic and current risk assessments and responses.

• Studies of risk in varying settings.

• Benchmark studies for various risk components.

Each society will need to engage with the questions particularly who has responsibility for risk-related decisions. Countries are likely to develop different approaches suitable for their specific building stock, climatic risks, culture and long-term vision.

Consideration needs to be given to the training, accreditation and verification that will be required to certify those (existing and new) professionals who provide risk assessment and the decisions based on these assessments. Clarity will be needed on forms of collaboration, coordination, and governance between the wide variety of actors and stakeholders who will be necessarily involved across different spatial and temporal scales. Transparency in decision-making and long-term accountability are vital.

With climate change fundamentally altering the risk environment for landscapes, buildings and infrastructure at an almost observable pace, the importance of preparing for an uncertain future is ever more critical. Not considering the impacts, vulnerabilities and exposure of projects on people and natural systems may rapidly become as unprofessional as ignoring other matters of health and safety and project performance, now embedded into good practice. It will be necessary to learn the lessons from previous shifts in professional culture and behaviours (Cole & Cooper 1988) and the associated goals attached to such subjects, to develop an effective movement for change that focuses on dealing with long-term risk: a movement intent on ensuring that the means to work through and prepare for future scenarios are put and kept in place.

Scale should be an essential consideration as many responses to climate risk will only make sense, or be affordable, when applied over a sufficient geographical area or range of assets. But equally resilience requires multiple and varied solutions, so that there are fallbacks at critical moments. There is no single solution to dealing with risk, but intelligent preparedness for the long term is key. Carrying out a series of short-term protective and preventative measures is likely to be greatly more expensive over the lifetime of a building, town or environment, and there is every possibility that such measures may at some point catastrophically fail in a progressively changing climate. Ways to value long-term preparedness urgently need to be developed and deployed.

As climate change is a present reality and more extreme and volatile weather conditions are anticipated in future with a high degree of confidence, the capacity to address and act appropriately in response to risks and uncertainties in the built environment sector becomes ever more pressing. There is an urgent need for work in this field—to be followed by sector leadership, for professional and other responsibilities on climate risk to be recognised and for individuals, organisations and governments to decide how to respond; whether though policy, guidance, best-practice exemplars, insurance reform, behaviour and culture change, codes of practice or regulation. This special issue can only offer a preliminary insight on this, but there is substantial and necessary work that must follow.

AI DECLARATION

No artificial intelligence (AI) was used in the research or writing of this manuscript.