Step Four: Assess Vulnerability and Risk

"As a general rule, systems that have high adaptive capacity are better able to deal with climate change impacts." - Climate Impacts Group

What You Need To Do

There are many ways to assess vulnerability and risk. In this photo the City of Castlegar's adaptation project is introduced to Engineers Canada's assessment tool for infrastructure. There are many different ways to define and measure vulnerability and risk. This Resource Kit presents one approach, but there are many others and each of the Phase 1 and 2 communities approached their vulnerability and risk assessment in a slightly different way. The approach described below is comprehensive and challenging. Reading through this entire section and consulting with appropriate Technical Support Team members before designing your approach are strongly encouraged. Communities should choose what works best for their needs. Some communities may prefer to skip this step altogether, develop a simplified version, undertake only a risk assessment or undertake only a vulnerability assessment. 

Vulnerability assessment (also known as finding the weak spots) involves estimating how sensitive or susceptible a system (e.g. a community) is to climatic changes, and how easily the changes can be adapted to. Vulnerability = Sensitivity x Adaptive Capacity

Risk assessment (also known as what to pay attention to first) adds a probability to each risk in order to determine priority planning strategies. Risk = Consequence x Probability

Assessing vulnerability and risk involves the following five components that can be done sequentially or concurrently:

  1. Complete Sensitivity Analysis
  2. Evaluate Adaptive Capacity
  3. Assess Vulnerability
  4. Determine Consequence and Probability
  5. Establish Priority Risks and Opportunities

Often this step is done in matrix form whereby a list of risks or impacts is compiled and then assessed for sensitivity, adaptive capacity, consequence and probability all at the same time. Each of these components can be undertaken with varying levels of public and steering committee involvement in a single or multiple workshop format, or in small working groups dedicated to particular impact areas. 

Links to useful community examples and guidebooks can be found at the bottom of this page.

1. Complete Sensitivity Analysis

Sensitivity is the degree to which a system is affected, either adversely or beneficially, by a climate-related stressor or human-induced pressure. "In order to determine whether a system in a given planning area is sensitive to climate change, ask the question: 'Will the systems associated with this planning area be significantly affected by projected changes in climate?' If the system is likely to be affected as a result of projected climate change, it should be considered sensitive to climate change." ~Climate Impacts Group

The sensitivity of systems can be classified as follows:

  • Low: Effects from climate change unlikely
  • Medium: Effects from climate change possible
  • High:  Effects from climate change very likely

Some questions that are helpful in assessing the sensitivity of a system include:

  • How exposed is the system to the impacts of climate change?
  • Is the system subject to existing stress?
  • Will climate change cause the demand for a resource to exceed its supply?
  • Does the system have limiting factors that may be affected by climate change?
  • For plant and animal species, is a species of concern in your system currently located near the edge or lowest elevation portion of its range?
  • What is the “impact threshold” associated with the system?

2. Evaluate Adaptive Capacity

Adaptive Capacity refers to the ability of a system to adjust to climate change and moderate potential damages, take advantage of opportunities, or cope with the consequences. "Evaluating adaptive capacity is the second step in the vulnerability assessment of a planning area. As a general rule, systems that have high adaptive capacity are better able to deal with climate change impacts."  ~Climate Impacts Group

The adaptive capacity of systems can be classified as follows:

  • Low: Actions are difficult and costly
  • Moderate: Actions possible with some disruptions and/or costs
  • High: Actions possible with minimum disruptions and costs

Note that you not only need to assess the ability of systems to adapt (often wrongfully assessed as static), but also the capacity to enact adaptation plans. To assess your community's adaptive capacity, you should be guided by the following questions:

  • Are the systems associated with this planning area already able to accommodate changes in climate?
  • Conversely, are there barriers to a system’s ability to accommodate changes in climate?
  • Are the systems associated with this planning area already stressed in ways that will limit their ability to accommodate changes in climate?
  • Is the rate of projected climate change likely to be faster than the adaptability of the systems in this planning area?
  • Are there efforts already underway to address impacts of climate change related to systems in this planning area?

While assessing adaptive capacity, attention should be given to what may limit adaptive capacity, including knowledge, technology, resources, or political will, and how that can be changed. 

3. Assess Vulnerability 

The City of Rossland conducted a vulnerability and risk assessment for food security and agriculture with their project Steering Committee. This photo represents the framework and process of the assessment. . Next you should combine your findings about sensitivity and adaptability to determine how and where your community is vulnerable to climate change. Sensitivity x Adaptive Capacity = Vulnerability

In general, vulnerability can be defined as follows:

  • High: High sensitivity + low adaptive capacity
  • Moderate: Medium sensitivity + medium adaptive capacity
  • Low: Low sensitivity + high adaptive capacity 

Vulnerability assessments are generally not static. Existing vulnerabilities will change, and new vulnerabilities will emerge as a result of many factors such as changes in the community, the emergence of new threats such as a new invasive species, and implementation of preparedness actions. It is helpful to revisit vulnerability assessments at pre-determined intervals to capture changes.

There can be a fair degree of subjectivity in the evaluation of sensitivity, adaptive capacity and vulnerability and the process can become confusing. The goal is to gather as much information as possible, but also to make some best guesses based on community and steering committee perceptions. Often the best data available will be qualitative. The examples provided from the Phase 1 and 2 communities illustrate that there are many different approaches to assessing vulnerability.

Community Example: Flooding Vulnerability Summary, Elkford's Final Report 2009

Flooding Risks

Sensitivity

(L, M, H)

Adaptive Capacity

(L, M, H)

Vulnerability

(VL,L,M,H,VH)

Flooding of buildings or lands

 

High

Low

Very High

Damage to bridge integrity

 

High

Low

Very High

Storm water management stress

 

Moderate

High

Low

Death/ injury to river recreation users

Low

Moderate

Low

Pumphouse floods and compromises water supply

High

Moderate

High

 

See the bottom of this page for more community examples of vulnerability assessments.

4. Determine Probability and Consequence

Probability and consequence are utilized to assess risk. Note that in some variations of the risk assessment process, vulnerability is substituted in for consequence. Risk = Consequence x Probability

Probability is the likelihood of some kind of event occurring. Some climate change impacts, such as higher temperatures, are virtually certain and will occur most years, while others, such as rainstorms severe enough to cause flooding, are less certain and may only occur every 10 years. In assessing probability, it is important to note whether the event will be ongoing or a single event.

Probability can be:

  • Low: Probability of an ongoing or single event less than 30%; Potential frequency of occurrence of a single event once every 30+ years.
  • Moderate: Probability of an ongoing or single event between 30 and 60%; Potential frequency of occurrence of a single event once every 5 to 30 years.
  • High: Probability of an ongoing or single event greater than 60%; Potential frequency of occurrence of single events once every <5 years to several times a year.

Probabilities can be assessed using information such as historical records, climate trends, insurance company records (fire/flood), input from scientific and engineering experts, staff, council and community perceptions.

Consequence is the seriousness or degree to which a community would be affected if the identified climate stress occurred. Questions to consider in assessing consequence are:  How costly would the impact be?  Would it result in potential loss of life?  How many people would be affected?  Would there be significant property damage or ecosystem damage?  Would it result in loss of livelihood? 

Consequence can be:

  • Low: Minor costs or inconvenience are possible. Very unlikely that loss of life or livelihood, large financial costs to the municipality or community, or significant property or ecosystem damage would occur.
  • Moderate: Moderate costs or significance inconvenience are possible. Unlikely that loss of life or livelihood, large financial costs to the municipality or community, or significant property or ecosystem damage would occur.
  • High: Possible or probable loss of life or livelihood, large financial costs to the municipality or community, or significant property or ecosystem damage.

Risk: Once probability and consequence are assessed, they are combined to produce some assessment of risk.

Risk can be:

  • Low: If consequence is low and probability is low, or if consequence is low and probability is moderate.
  • Moderate: If consequence is moderate and probability is moderate, if consequence is high and probability is low, or if consequence is low and probability is high.
  • High: If consequence is high and probability is high, or if consequence is high and probability is moderate.

As with vulnerability assessment, there can be a fair degree of subjectivity in the evaluation of consequence, probability and risk and the process can become confusing. The goal is to gather as much information as possible, but also to make some best guesses based on the data available and community and steering committee perceptions.

5. Establish Priority Risks and Opportunities

After vulnerabilities and risks have been assessed, the community must determine priority risk areas on which to focus climate change adaptation actions and strategies. In general, the following guidelines can be utilized:

 

Low Vulnerability

High Vulnerability

High Risk

MAY be priority action planning area

SHOULD be a priority action planning area

Low Risk

UNLIKELY to be a priority action planning area

 

MAY be a priority action planning area

 

However priority risks will also be determined by the level of risk that different communities are willing to accept (risk tolerance). Thus assessing priority risks is a complex process for which each community must set their own criteria.

Useful Material

Vulnerability and Risk Assessments

Community Example:  City of Castlegar Vulnerability and Risk Assessment Backgrounder for Food Security and Agriculture   

Community Example: City of Castlegar Food Security and Agriculture Worksheets 

Community Example: City of Castlegar Vulnerability and Risk Assessment Framework for Water

Community Example: City of Rossland Vulnerability Assessment Framework for Food Security and Agriculture

Community Example: City of Rossland Vulnerability Assessment for Food Security and Agriculture Summary

Community Example: RDCK Area D/Village of Kaslo Risk Assessment for Water and Local Food Production

Community Example: District Elkford Risk Assessment Summary for Flooding (including definitions) 

Community Example: City of Kimberley Template for Vulnerability and Risk Assessment    

Community Example: City of Kimberley Water and Forests Worksheet

Presentations and Guidebooks

Vulnerability Assesment Graphic - This flow chart shows the conceptual flow of information and questions in a vulnerability assessment.

Presentation on Vulnerability and Risk Assessment Methods for Climate Change Adaptation - This presentation focuses on methods for doing Vulnerability and Risk Assessments.

Climate Change and Infrastructure Vulnerability Assessment - Introductory Workshop to the City of Castlegar on Vulnerability Assessments for Infrastructure

Climate Impacts Group (CIG) Preparing for Climate Change Guidebook - This guidebook was especially utilized by the District of Elkford, City of Rossland and RDCK Area D/Village of Kaslo during their Vulnerability and Risk Assessment Processes. Chapters eight and nine have comprehensive information on how to conduct a vulnerability and risk assessment.

Ontario Municipal Risk Assessment Guidebook - This guidebook was used extensively by the District of Elkford. The guidebook presents a risk-based approach that can be used to facilitate municipalities’ efforts to adapt to climate change through both longer term planning and short-term responses. 

Public Infrastructure Engineering Vulnerability Committee - The Vulnerability Committee was created to conduct an engineering assessment of the vulnerability of Canada's public infrastructure to the impacts of climate change. It is co-funded by Natural Resources Canada (NRCan) and Engineers Canada.