Evolution of extreme events resulting from cumulative emissions

This project focuses on the consequences of extreme events linked to climate change. In particular, the aim here is to analyze the direct link between CO2 emissions and socio-economic impacts such as loss of worker productivity during episodes of intense heat.

Project details

Scientific program

2014-2019 programming

Theme(s) and priority(s)

Climate Scenarios and services

Start and duration

February 2017 • February 2019

Project Status

Completed

Principal(s) investigator(s)

Yann Chavaillaz

Hydro-Québec

Damon Mathews

Université Concordia

Philippe Roy

Ouranos

Context

Our responsibility regarding ongoing climate change is no longer in doubt. Climate models and observations show that changes are directly linked to the rate of our emissions. These include an increase in the frequency and intensity of extreme events such as heat waves. Heat exposure can have a number of socio-economic impacts, such as loss of productivity at work.

Thus, this project looks at the consequences of extreme weather conditions and seasons, and the tools that can be implemented to adapt to them. The tools to be developed could concern academic research or tools for impact studies or decision support.

Objective(s)

Linking cumulative carbon emissions, increased exposure to heat and its economic impact in terms of lost productivity

Methodology

Use CMIP5 climate projections under a multi-model approach (8 models and 3 selected GHG emission scenarios).
Determine heat exposure using a simplified version of WBGT (wet-bulb globe temperature). Several WBGT thresholds were identified, corresponding to a fraction of working time during which an average individual would need to rest in a non-exposed environment. This loss of personal productivity was translated into economic loss based on country statistics from the International Labor Organization (ILO). Statistics were compiled by country, by GDP level and on a global scale.

Results

The project produced the following results:

A linear relationship between heat exposure and cumulative carbon emissions has been identified. Linearity was verified on a global scale, and then on different regional scales where climate models were in agreement.
Differences in the linear relationship were highlighted between the different greenhouse gas emission scenarios. These are explained by the effect of greenhouse gases other than CO2.
This is the first time that an economic impact has been linearly linked to our emissions. According to a socio-economic scenario without emissions mitigation, each gigatonne of CO2 emitted generates a loss of around 0.4% of annual GDP on a global scale, linked to the loss of productivity of outdoor workers.
As with many other climate change-related impacts, this economic loss will be felt more acutely in countries with the least resources (i.e. lower GDP).
A new decision-making tool applicable to other economic impacts could be developed as a result of this project.

Benefits for adaptation

While the probability of extreme events remains low, their economic impact could be enormous. Extreme events play an important role in human and economic losses. Moreover, the characteristics of extreme events could change over the course of the 21^st century, driving up the cost of material and human damage. Accordingly, the financial and insurance sectors are taking a keen interest in extreme events and their many impacts on living conditions. The development of new approaches to producing relevant climate scenarios is likely to attract the attention of several economic sectors.