Evaluation of the impacts of climate change and its costs for Quebec and the Quebec government

In its most recent report, the Intergovernmental Panel on Climate Change reaffirms the risks of climate change to marine and terrestrial ecosystems and biodiversity, water supplies, economic sectors, rural and urban environments, and human safety and health. The impacts on some of these sectors are starting to be better understood and, for some issues, sufficiently quantified to estimate their costs. However, at present, there is no comprehensive study estimating the costs of all the impacts of climate change for Quebec. Several key industries in Quebec will be affected, including agriculture, fisheries, forestry, tourism, and hydroelectricity production and energy demand. These impacts will result in costs, and sometimes opportunities, for citizens and businesses as well as the various levels of government. That is why it is essential to quantify them.

• To identify and quantify the impacts of climate change on health and infrastructure and to assess the costs to the state as well as to society as a whole.

• Identification of recent literature on climate change impacts for each issue, as well as available databases, in order to identify the consequences that may generate costs

• Statement of hypotheses for each issue, and validation by focus groups

• Development of an economic analysis model that allows for a monetary evaluation of the impacts of climate change and includes costs to the government and, where available, other costs to society.

Given the available data and the length of the mandate, the analysis focused on a few specific issues:

• Health: heat, zoonoses (Lyme disease and West Nile virus) and pollen

• Infrastructure: coastal erosion, thawing permafrost, flooding

The analyses considered a time horizon of the next fifty years and a status quo socio-economic scenario, i.e. all other things being equal (no growth or demographic, economic, political changes, etc.). It was assumed that all existing laws and regulations would remain in force, such as prohibitions on construction in recognized high-risk areas. No new adaptation measures were considered, but those already in place (such as those in the health sector) were incorporated into the analyses. All costs associated with emergency planning and extreme event responses were also accounted for in the analysis.

Lastly, to verify the impact of the various hypotheses, a number of sensitivity analyses were carried out where relevant (aging of the population, population growth, land value, etc.).

The key findings of the analysis are summarized below:

• The costs without climate change are already quite high for all issues.

• With regard to the impact of climate change, health costs will be particularly high, particularly for heat and pollen.

• Similarly, the costs of coastal erosion are relatively high: several thousand buildings and a few hundred kilometres of roads and railways are at risk over the next 50 years.

• The greatest costs for northern regions appear to be more closely related to extreme events, as proper design and regular maintenance could offset the effects of the thawing permafrost.

• Floods already cost an average of $70M/year, with variations ranging from $0M to $182M/year, based on historical data.

Ce projet est financé par le gouvernement du Québec et répond aux objectifs du Plan pour une économie verte 2030.

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