Integrated Guidance for Climate-Resilient Infrastructure

Based on the review of over 150 existing publications and tools on climate-resilient infrastructure, the following key actions have been identified to support practitioners in integrating climate resilience into infrastructure development in the Prioritisation phase of the infrastructure lifecycle. These actions are summarized in the table below and grouped by theme. Each action is further elaborated on in this section and references and links to key publication and tools are shared.

View all Themes and Actions

Theme 1: Robust Decision-Making Approach

2.1.1 Institutionalize adaptive management and robust decision-making approaches

The institutionalization of robust decision-making processes within government and corporate systems is essential to allow for consistent, effective action in the long-term to adapt to climate change, avoiding short-term politically based decision-making. The Policies and Plans phase of the infrastructure lifecycle summarizes guidance on embedding climate resilience into government structures, plans and policies. Decision-making processes that promote climate resilience, including adaptive management strategies that recognize the inherent uncertainties involved in making decisions related to climate change, must also be institutionalized.

Adaptive management strategies to decision-making explicitly allow for evolving approaches to the management of climate risks. Adaptive management promotes flexible decision making that can be adjusted in the face of uncertainty as new outcomes from management actions and other events develop^[1]. Figure 1 within this report helpfully illustrates the differences between conventional management and adaptive management strategies^[2].

Adaptive management has most often been used for decision-making related to natural resources management but has been promoted more recently as an effective strategy for climate resilient infrastructure. The UNDP’s guidance on climate-resilient infrastructure highlights the need to “create adaptive systems for managing evolving risks: systems for making continuous decisions (rather than developing discrete solutions) must be in place at national, subnational and community levels” ^[3]. The following documents provide guidance on adaptive management approaches:

• Guidelines for Resilience in Infrastructure Planning: Natural Hazards (Section 3.1) ^[4]
• Informing an Effective Response to Climate Change ^[5]
• Ready for Tomorrow: Seven Strategies for Climate-Resilient Infrastructure (Recommendation 1) ^[6]
• Climate-resilient infrastructure: Getting the policies right ^[7]
• What is a pathways approach to adaptation? ^[8]

Learning and IterationLearning and IterationAligned with the concepts of adaptive management is robust decision-making (RDM), an iterative approach used to assess and compare the resilience of several strategies against a suite of future climate scenarios.Future-Oriented PlanningFuture-Oriented PlanningRDM can negate a significant amount of uncertainty by ensuring resilience to a plethora of future climate scenarios through a process of probabilistic risk modelling and stress testing. Relevant stakeholders and decision makers can be engaged to identify vulnerabilities to future shocks and stresses which can then be addressed and managed early in the lifecycle and thus reducing the potential for regret, vulnerability lock-in and premature climate-related obsolescence ^{[9] [10] [11]}. Depending on resource availabilities, a number of different assessment approaches can be utilized under RDM to identify and assess future scenarios for prioritisation purposes, including expert judgment, indicators, formulas, and processes-based modelling. Each of these approaches entail differing degrees of complexity, uncertainty and demands on data and resources ^[12]. Learning and IterationLearning and IterationIn addition, as more data become available, either through increased collection or through a shift towards more open data distribution, the analytical tools used under RDM can be updated. This reference provides more information and case studies on RDM in the context of climate adaptation planning ^[13].

Use of the prioritisation and decision-support tools described in this lifecycle phase can be embedded into formal decision-making by requiring their use in project preparation or implementation or by adopting them as part of the review process by an advisory panel. Table 5.2 (pg. 62) in a UNDP report shows an example of a matrix used to evaluate several adaptation options based on specified qualitative and quantitative criteria ^[10]. Tool4.2 within the ICLEI ACCCRN Process provides a step-by-step guidance on one methodology for prioritising climate-resilience interventions based on pre-identified resilience indicators ^[14].

Theme 2: Holistic Thinking in Options Evaluation

In developing and deciding upon the strategic approach for infrastructure development to meet identified needs and established goals, and in prioritising among various identified projects, it is important that practitioners take a holistic perspective. This theme explores the systemic considerations that must be made when prioritising specific projects over others and deciding upon the strategic direction of a selected project. It should be noted that the approaches described in this section also apply at other stages of the infrastructure lifecycle when decisions are made, including in the project preparation phase (Phase 3) and the design phase (Phase 6).

2.2.1 Develop a set of diverse options for evaluation

The prioritisation process begins with the identification and development of different options or strategies that meet the overall vision and needs that have been identified for a particular place, community or sector. The following considerations are useful when developing options for evaluation:

• Consider a mix of ‘hard’ (i.e. infrastructure related) and ‘soft’ (i.e. non or minor infrastructure-related such as policy changes or capacity building, also referred to as ‘no build’ options) solutions ^{[14] [4]}. Options that focus more on preparedness tend to have lower up-front costs and therefore might be more politically palatable in resource-scarce conditions than more capital-intensive options focused on risk reduction and adaptation which are ultimately more cost effective.
• Environmental Co-BenefitsEnvironmental Co-BenefitsConsider ‘green’ (i.e. nature-based) and ‘blue’ (i.e. water-based) solutions in addition to traditional ‘grey’ infrastructure, as well as hybrid solutions.
• Consider opportunities for rehabilitation and/or retrofit of existing infrastructure in addition to new construction.
• Service Continuity and ReliabilityService Continuity and ReliabilityConsider solutions with different levels of performance in the face of climate risks. When comparing and evaluating solutions, it is essential that these differences are recognized when identifying costs and benefits.
• Consider solutions that link to or are synergistic with other existing efforts underway^[14].

Multi-disciplinary workshops can be useful tools for generating a wide range of options to meet a particular objective ^[15]. Intervention Mapping, part of the ICCLEI ACCCRN Process ^[14] (Tool 10), is a useful tool to use at such a workshop for identifying solutions to an identified need.

2.2.2 Take a multi-hazard approach to developing and evaluating options

In developing, evaluating, and selecting infrastructure solutions, primary to enhancing climate resilience is understanding the present and future climate hazards (and other hazards) to which the infrastructure asset or system is, or could be, exposed. Increasingly, observations of historical hazard events as an indicator of future risk are becoming less reliable, given the growing and dynamic threat that climate change poses. In addition, the development of many infrastructure projects can span decades, leading to deep uncertainty associated with the climate hazards to which they will be exposed. Systems ThinkingSystems ThinkingNearly every infrastructure asset is at risk of being impacted by more than one hazard, either directly or indirectly through linkages to wider systems. Despite this, conventional sensitivity analyses often address these shocks, stresses and impacts individually. Breaking these silos down by employing a multi-hazards approach to risk assessment and decision-making can help to prioritise more resilient solutions ^[6].

Future-Oriented PlanningFuture-Oriented PlanningTaking a multi-hazard approach when evaluating options requires the identification and characterization of hazard scenarios including existing exposure to climate hazards as well as future expected hazards, which could be more extreme, more frequent or novel ^[4]. Depending upon the context, scope and scale of the infrastructure project, the following types of hazard scenarios may need to be evaluated ^[16]:

1. Independent events: hazard events caused by different triggers that can be considered independently, for example, an earthquake and a flood. Even so, there may be situations in which the optimal design for one hazard increases the vulnerability to another independent hazard. A common example of this is the raising of buildings on stilts to reduce flood vulnerability, which in turn, increases seismic vulnerability. It is therefore important to identify balanced solutions that limit risk across anticipated hazards, even if the hazards are evaluated independently.
2. Coupled events: hazard events caused by the same trigger that must be considered simultaneously in risk assessments, for example, flooding and extreme wind loads.
3. Influence of one hazard on the disposition of another: where one hazard has the potential to exacerbate the impact of another hazard, now or in the future. For example, a wildfire may lead to increased flood or landslide risk.
4. Cascading hazards: one hazard causing the next, resulting from interdependencies with other infrastructure and systems. An example of this is an earthquake triggering a landslide which dams a river and leads to a dam break. The evaluation of these scenarios becomes more complex and ambiguous as the scale of an infrastructure project increases. The recommended approach for evaluating these scenarios is to use an ‘event tree’ (p.50)^[17].

A risk matrix (p.53)^[16], or a likelihood and consequences matrix (p.244) ^[18], can be a useful tool for identifying the most important risks and scenarios that should be the focus of the evaluation of options when resources are limited.

2.2.3 When evaluating options, consider the entire lifecycle cost as well as the complete system

Cost-benefit analysis (CBA) is a common tool for decision-making related to infrastructure investment, and it can be useful for climate-resilient infrastructure provided it is approached holistically and its limitations are understood. When the analysis is conducted using only upfront capital costs and the benefits are limited to only quantifiable, monetary benefits, it has the potential to impede the prioritisation of climate resilient approaches, given the increased upfront costs associated with integrating resilience-building mechanisms such as redundancies and excess capacity. The difficulties in accounting for costs associated with poor resilience and the economic benefits of resilience considerations are also a factor. Systems ThinkingSystems ThinkingTo move toward the prioritisation of more resilient solutions, a more holistic options evaluation approach must become the business-as-usual approach ^[6].

Three key considerations can aid in more accurately identifying the true costs and benefits of options at the decision-making stage. If these considerations are acknowledged at the prioritisation and option evaluation stage, the selected option will be more likely to have factored in the benefits of long-term risk avoidance and other downstream benefits in addition to balancing inevitable trade-offs between climate change mitigation and adaptation.

Whole Life Cycle: Future-Oriented PlanningFuture-Oriented PlanningA whole life cycle approach is one in which the costs and benefits and the positive and negative impacts of an infrastructure project are evaluated across the entire lifetime of the asset, including long-term operation and decommissioning of the asset. Applying this approach earlier on in the prioritisation and early-stage planning of infrastructure projects can lead to solutions that more effectively avoid risk or environmental impacts and reduce long-term operational and maintenance costs ^[6]. For example, non-asset solutions such as mangrove restoration might be identified over physical interventions such as flood barriers ^{[19] [20]},^[21]. Acclimatise (2011) provides guidance on conducting a whole lifecycle appraisal, including managing additional risks from climate change, aligning with other appraisals, and integrating adaptation and resilience measures into the project lifecycle.

Systems Thinking:Systems ThinkingSystems Thinking Systems thinking, recognizing an infrastructure project as a component within a much wider and complex system or series of systems, is helpful for the identification of triple bottom line impacts as well as in the assessment of whole life cycle impacts discussed above. Systems thinking can help identify cross-sector dependencies and interdependencies that may have costs, risks or impacts associated with them. For this approach to be effective, it must be interdisciplinary to account for discipline-specific biases^[4]. It must also look across administrative boundaries, especially when considering the impacts of climate hazards. The following references provide more guidance on systems thinking approaches for prioritisation:

• • A System-Wide Approach for Infrastructure Resilience: Technical Note ^[22]
  • ISO 14090:2019: Adaptation to climate change – Principles, requirements and guidelines (Annex A) ^[23]
  • Non-paper Guidelines for Project Managers: Making vulnerable investments climate resilient (Section 1.7.7) ^[24]

Other considerations and qualifications related to the prioritisation of climate-resilient infrastructure include the following:

• It is important to carefully select a ‘base case’ to which the other intervention options can be compared. This base case is typically defined as ‘business-as-usual’. The costs of inaction with respect to identified climate change hazards should be identified or quantified as part of this base case ^[4].
• CBA does not explicitly account for the value of adaptive management strategies that preserve future options, thereby overvaluing grey infrastructure solutions, even though a flexible approach to resilience may result in greater social and environmental benefits and avoided risks over time ^[6].
• Focusing exclusively on Net Present Value (NPV) of a CBA in the prioritisation of projects will favour resilience projects in higher-income areas and populations where the value of avoiding climate-related damage is higher ^[9].
• Option evaluation must recognize not only the value of resilience in reducing climate-related losses but also the fact that climate-resilient infrastructure can be an enabler of other development and investment as well as increased land value ^[25].
• Section 4.4 of these guidelines provides three key principles for informed decision-making for climate-resilient infrastructure based on cost-benefit analysis when there is a high degree of uncertainty in the climate hazard scenarios ^[4].
• Evidence-Based Decision MakingEvidence-Based Decision MakingA holistic approach to options analysis relies significantly on the availability of reliable data as well as the capacity and resources to conduct the assessments. In many instances, one or more of these criteria will not be available to relevant decision makers. For these cases, Theme 3 outlines some approaches that enable decisions to be made under deep uncertainty or where significant resource constraints must be considered.

In most cases, it will not be possible to quantify all identified costs and benefits in a manner that allows for an apples-to-apples quantitative comparison of Net Present Value (NPV) of different options. Evaluation approaches that allow for combined quantitative and qualitative comparisons are more effective in assessing climate-resilient solutions ^[6].

2.2.4 Make decisions with an eye towards the long-term

Future-Oriented PlanningFuture-Oriented PlanningWhen evaluating options, it is critical to consider which ones are most robust and adaptable to future uncertainties. Stress-testing available options against plausible futures, including ones that assume low-likelihood, but high-consequence events, allow decision makers to prioritise options that acknowledge and balance acceptable risk against deliverable solutions, thus minimising regret and avoiding maladaptation ^[9][11]. Assessing a suite of physical, social, and institutional interventions in each future scenario will further help to prioritise the most resilient and actionable approaches ^[12]. For insights into future scenarios for infrastructure, refer to this report by the Global Infrastructure Hub. ^[26]

The following are three examples of uncertainties that should be considered in addition to the uncertainty of climate hazards themselves.

• Population changes: When the prioritisation of infrastructure projects is made based on cost-benefit analysis and the other approaches described in this section, the results can be highly influenced by demographic and population data. Additionally, downstream decisions related to the operating capacity and location of infrastructure are also dependent on demographic data. Future-Oriented PlanningFuture-Oriented PlanningAs populations grow, shrink, and migrate, in part driven by climate trends, it is important to use best estimates of future population when prioritising and planning infrastructure projects to deliver infrastructure to those areas that will benefit from it most and avoid underutilized or overburdened assets. Projections related to both the number of people and where they are expected to live are needed.
• Technology evolution: Just as populations are shifting dynamically, technology is also evolving at a rapid pace, including the rise of InfraTech (automation, Internet of Things, distributed ledger technology, visualization, BIM, AI and other advanced analytics) reducing manual labour needs in all phases of the infrastructure value chain^[26]. Future-Oriented PlanningFuture-Oriented PlanningWhen decisions about the prioritisation of infrastructure are made based on assumptions such as number of users served, long-term costs of operation, and jobs created, it is important to evaluate future technology scenarios and how they might impact decision-making.
• Level of resources and capacity available for maintenance: When decisions are being made about the selection of one option over another for a particular infrastructure project, Future-Oriented PlanningFuture-Oriented Planningthe decision-making must factor not only the costs associated with long-term maintenance as part of whole life cycle thinking but also the feasibility of the actual strategy for ensuring long-term maintenance needs are met. Capacity BuildingCapacity BuildingThis includes assessing the reliability of the funding source for long-term maintenance needs as well as the human resources and skill levels required for proper maintenance. Without these in place, a well-intentioned project with high climate-resilience value initially may degrade over time and not perform as intended.

Theme 3: Distinguishing among Decision-Making Tools

While Theme 2 covers guidance related to the general mindset for approaching prioritisation and decision-making for climate-resilient infrastructure, this section references specific decision-making tools and frameworks that can be employed by decision-makers in identifying and prioritising the most effective climate-resilient approaches, including when faced with deep uncertainty in the parameters of the decision-making or a lack of data. It should be noted that the tools described in this section may also apply at other stages of the infrastructure lifecycle when additional decisions are made regarding the direction of an infrastructure project, including in the project preparation phase (Lifecycle Phase 3) and the design phase (Lifecycle Phase 6).

2.3.1 Identify the appropriate decision-making tool

Multi-criteria analysis, cost-benefit analysis and life cycle cost analysis are useful in identifying an optimal solution when there is agreement on the probabilities of various future risk scenarios playing out and sound data are available, which are rarely the case in the context of climate change. As described in Theme 1, robust decision-making can be considered as the broad umbrella for decision-making in the face of climate change as it can be used in situations when it is not possible or practical to characterize the most likely scenario to which infrastructure must be optimized (see Action 4.2 Hallegatte, et al.,2019). Using a robust decision-making approach, multi-criteria and cost-benefit analysis tools can be applied to a suite of climate risk scenarios and a suite of delivery options to identify the one that has the greatest benefit and lowest costs in aggregate for the most plausible future scenario or scenarios. In resource-scarce conditions, a real-options analysis can be used (see Action 2.3.2). Equity and Social Co-BenefitsEquity and Social Co-BenefitsAs part of any evaluation strategy used, a triple-bottom-line approach should be taken that considers the positive and negative social, environmental and economic impacts of a project. This valuation approach guide provides a decision tree to support in selecting among valuation and decision-making approaches.

• Multi-Criteria Analysis (MCA): MCA covers a broad range of decision-making approaches. MCAs are used to evaluate a number of options using a set of weighted criteria. A score is obtained, for each option, and the highest selected. Equity and Social Co-BenefitsEquity and Social Co-BenefitsAn MCA is useful in instances where socio-cultural or environmental considerations are evaluated in non-monetary terms, as both quantitative and qualitative considerations can be taken into account. Page 28 of this UNFCCC Report ^[27] provides a succinct summary of the steps involved in conducting an MCA and case studies are provided on Pages 30, 33 and 35.
• Cost-Benefit Analysis (CBA): If the main consideration of an analysis is efficiency, a CBA can be performed to evaluate the cost-benefit ratio using a single metric. Presenting the results in monetary terms allows decision-makers to efficiently compare options using a single value. Environmental Co-BenefitsEnvironmental Co-BenefitsThis tool is best used in conjunction with other, more holistic, ones that internalize non-market costs and benefits, such as ecosystem services. 12 of the UNFCC Report ^[27] outlines the considerations decision-makers must account for, with case studies on Pages 14, 16, 18 and 20.
• Cost Effectiveness Analysis (CEA): Where benefits are not easily monetized, such as in the case of public health or ecosystem services, CEA can be used to identify the least costly approach amongst a suite of options. CEA are particularly appropriate in instances where prioritization of a single solution rather than a combination is the aim. ^[27] Pages 22–27 of the UNFCC Report provide guidance and case studies.
• Lifecycle Cost Analysis (LCCA) LCCA is a cost driven assessment approach, used to evaluate and compare the lifecycle costs of various options, including capital, operations, management, and replacement costs. Equity and Social Co-BenefitsEquity and Social Co-BenefitsThough this approach does not typically consider environmental or social costs, it is an approach recommended by the American Society of Civil Engineers ^[28], which calls for sustainability, resilience, and environmental impacts to be considered alongside the economic lifecycle cost. Page 9 of this ASCE Report ^[28] points stakeholders to relevant LCCA methodologies.
• Lifecycle Analysis (LCA): Environmental Co-BenefitsEnvironmental Co-BenefitsAn LCA is a cradle-to-grave assessment of environmental impacts, often performed in conjunction with an LCCA, as per ASCE’s recommendation ^[28]. The Envision guidance manual ^[29] briefly outlines the use of an LCA as part of an energy park development in The Netherlands.
• Triple Bottom Line (TBL): To comprehensively assess the costs and benefits of project options across their whole life cycle, a TBL approach, one in which social and environmental impacts (immediate and cumulative) are considered alongside economic considerations, is recommended. These social, environmental, and economic impacts pertain not only to the infrastructure options themselves but also the climate shocks and stresses they may be exposed to in their lifetime. Future-Oriented PlanningFuture-Oriented PlanningMarginal higher upfront costs of solutions that anticipate an improved level of performance against climate hazards can then be compared against the increased benefits of avoided climate risks and losses. Other indirect impacts, including unintended negative social and environmental consequences or co-benefits of infrastructure can also be identified. The scalable nature of approaches such as the TBL Assessment Framework can facilitate TBL assessment at different levels including high-level, national decision making. A TBL assessment will identify both positive and negative impacts which can then be carried forward into a multi options evaluation process.

2.3.3 Perform real options analysis under resource scarce conditions

Future-Oriented PlanningFuture-Oriented PlanningIn circumstances where resources are limited and there is a lack of climate hazard data and other relevant data, and decisions can be made in stages with some degree of flexibility, Real Options Analysis (ROA) provides the ability to defer costly decisions that might reduce future flexibility and prematurely lock in potentially inadequate solutions. By evaluating response pathways, consisting of a series of decision points, the approach gives decision makers the opportunity to prioritize less-resource intensive short-to-medium term interventions that can be acted upon under less uncertainty while also avoiding a commitment to one specific long-term strategy. Partial and potentially reversible interventions or decisions can be made that preserve future options and allow time for more learnings and data to become available for more informed decision-making ^[30]. Resource-intense interventions can be postponed to a later stage, when uncertainty is reduced ^{[4] [31] [32]}.

This paper provides more information on real options analysis for coastal adaptation, including several case studies. It also provides the following summary of how ROA differs from traditional economic analysis ^[30]:

“ROA shows that sometimes it makes more sense to wait for new information rather than investing immediately.”

“ROA shows that it may make sense to start the initial stages of a project (keep it alive) as the project may become more attractive at a later date.”