Identifying high-priority compound climate events in Quebec: An exploratory study

This project has highlighted combined climate events that should be prioritized in Quebec by targeting the information needs related to these events.

Project details

Scientific program

Programmation 2020-2028

Theme(s) and priority(s)

Economy - Energy Security - Water Availability - Food Systems - Social and Health Challenges - Extreme Events - Adaptation of Living Environments - Climate Science and Climate Services

Start and duration

January 2024 • March 2025

Project Status

Completed

Principal(s) investigator(s)

Anissa Frini

UQAR

Context

In Quebec, awareness of the increased frequency and impact of certain compound events or hazards is swelling. The subject is attracting widespread interest and should therefore be considered more often in vulnerability and risk analyses. Furthermore, a number of organizations from different sectors (municipal, infrastructure owners, industries, farmers, etc.) that are already engaged in adaptation are now ready to tackle more complex issues and assess their level of preparedness for compound events. However, they need a better understanding of how these hazards are changing, and therefore need access to reliable information that is useful for decision-making. From a scientific point of view, the study of compound events poses a number of challenges, particularly in climatology: the rarity of episodes versus the quantity of simulations required, the great diversity of combinations, etc. On a practical level, the challenge lies in the number of combinations of events of interest, which differ from one organization to another, and in the confusion between compound climatic events and cascading consequences.

The aim of this project is to identify the compound events to be studied in Quebec and identify which ones are high-priority. This project also contributes to meeting adaptation challenges, since the identification of compound events, vulnerabilities and impacts will enable us to deepen our knowledge on this subject and take better preventive action.

Objective(s)

General objective: to identify and prioritize the compound events worth studying in Quebec.

This assessment of the needs related to compound events will ultimately guide and structure efforts to improve and share the climate knowledge required for decision-making by the various parties involved in adaptation.

Sub-objectives:

To identify compound events of interest to Ouranos partners and collate information on the vulnerability of a variety of stakeholders and the potential impacts on them.
To identify the high-priority compound events based on decision criteria selected and weighted in collaboration with Ouranos.

Methodology

The project is divided into two main phases.

Phase 1: Conduct qualitative exploratory research to identify the compound climate events of interest to Ouranos partners, and gather information on vulnerability, the nature and severity of the potential impacts of these events, and the ability to cope with them.
Phase 2: Rank the compound events mentioned by Ouranos partners in terms of priority based on a multi-criteria approach.

Results

Several study respondents mentioned changes in the way hazards manifest themselves, noting that events have tended to change in recent years, producing more unprecedented and often more unpredictable scenarios.

45 different compound events were identified during the interviews. Of these, 18 were identified as being of particular concern, and were chosen as the subject of interviews. These 18 events involved issues related to water deficits, flooding, flooding together with water deficits, wind, forest fires, and sudden variations in temperature and weather conditions.

The study also showed that some of the compound events examined could have serious consequences, and the vulnerability of certain areas and populations was often deemed significant. Certain events also raise serious concerns for the future. In addition, the project helped target the information needs associated with compound events, both in terms of the type of information required and the formats in which partners wish to access it.

Prioritization was done using a multi-criteria approach. The various criteria were weighted with the collaboration of the Ouranos climate science team to produce the hierarchical tree below.

Figure 1. Hierarchical decomposition tree

This led to three types of ranking. The first was based on perceived risk criteria, the second on scientific feasibility criteria, and the third on both perceived risk and scientific feasibility.

Benefits for adaptation

The results will enable Ouranos to continue its knowledge-sharing work and to initiate the development of new knowledge on the compound climate events of concern to its partners.

This report is the first step in prioritizing the work that needs to be done to effectively meet the needs of Ouranos partners.