Vulnerabilities

The Intergovernmental Panel on Climate Change (IPCC) defines vulnerability as “the degree to which geophysical, biological and socio-economic systems are susceptible to, and unable to cope with, adverse impacts of climate change” (Schneider et al. 2007, pp. 783). Assessing vulnerability is more complicated that merely assessing the potential impacts of climate change. Vulnerability is composed not only of the direct impacts of climate change on a variety of systems, but also our ability to deal with these impacts.

Vulnerabilities to climate change vary significantly across regions. This diversity is due to several factors. First, direct impacts of climate change will vary across regions due to their specific characteristics. Second, social structures also vary across region and will be impacted differentially as human and non-human systems are highly integrated. Third, the capacity of regions to adapt to climate change will vary for geophysical, biological, and social reasons. The ability of a region to adapt to climate change will in turn impact its vulnerability. Fourth, all regions are constantly undergoing a process of change. There are non-climatic drivers already at play in shaping regions. For example, many regions are already facing concerns about resource depletion and access to harvestable resources independent of climate change. Some of the drivers for these concerns are independent of direct climate change and may include urbanization, changing resource markets, technological shifts, and other broad changes. Climate change will interact with these region specific trends in different ways. Because vulnerability has the potential to vary by region, it becomes important for each region or community to assess its own key vulnerabilities so that it can optimize adaptation decision-making.

Identifying Key Vulnerabilities

Because climate change impacts vary significantly across regions, it is important to identify which ones are most important for each community or region. One of the useful frameworks for assessing key vulnerabilities was developed for the IPCC. This framework consists of seven central considerations (adapted from Schneider et al. 2007), each of which contains questions that can guide an assessment of key vulnerabilities.

1) Magnitude
How big is the predicted impact of climate change?
How intense is the predicted impact?

2) Timing
When is the impact expected to occur? Relatively soon or in the more distant future?
How rapidly is the change likely to be?

3) Persistence and Reversibility
Are the impacts predicted for your region likely to be long-lasting, or are they temporary?
Are any of the impacts you are facing irreversible?

4) Likelihood and Probability
How likely are the potential impacts predicted for your region?
Are you aware of any vulnerabilities (geophysical, biological, or social) which already exist and which may be impacted by climate change?

5) Potential Adaptability
Are there adaptations that could cushion the possible impacts in your region?
What would be required to implement these adaptations (socially, economically, technically?
Are these adaptations culturally, economically, politically and environmentally feasible?
Do you have the required resources to implement these adaptations?
Are there incentives to strengthen support for these adaptations?

6) Distributive Consequences
How smoothly are the potential impacts distributed?
Are there any groups that are more or less likely to receive a greater share of the positive or negative impacts from the changes you have identified for your region?

7) Importance of Vulnerable Systems
How important are the systems you have identified as potentially vulnerable? Are these systems that are essential to the well-being of your region?

These questions are designed to start identifying aspects of your community that may be more vulnerable to climate impacts than others. An important element of this however, is also recognizing which areas are sufficiently within local jurisdiction and that decisions taken locally have the ability to reduce vulnerability. The ability to make decisions that will reduce vulnerability is known as adaptive capacity and is central is planning local adaptation.

Decision Making Support Tools

Influence Diagrams

Regional climate scenarios help identify the possible range of regional outcomes for particular variables, such as temperature or precipitation. In order for this information to be meaningful, it must be linked to biophysical, socio-cultural, or economic regional systems. Influence diagrams are a useful way of doing this.

An influence diagram can start with the predicted changes to key variables and then elaborate on some of the possible impacts of this on the system in question. The process of developing and using influence diagrams can help identify linkages among impacts, points of high uncertainty in the system, potential points of leverage, and possible final outcomes.

An example of a climate change influence diagram is presented below - please click on the thumbnail to view. This diagram looks at the potential impact on fry entering a lake in winter under a condition of climate change. As can be seen, each step of the process is identified and considered.

This influence diagram shows a relatively specific aspect of a system, just the fry entering the lake, but influence diagrams can be conducted at a range of scales and levels of detail.