Development of a future bioclimate profile for Nunavik

Current climate disturbances in Nunavik are significant and are likely to intensify by the end of the century, which will affect the local fauna and vegetation, as well as infrastructures and the populations who live there. However, Québec’s northern territory presents several specific challenges when it comes to characterizing its climate, in particular because of the vast expanse of the territory, the very low density of meteorological and hydrological observation stations and the coastal influence due to its geographic location.

These challenges obviously have an impact on bioclimate and hydroclimate analysis. It is therefore vital to pay close attention to the different climate products available for this region in order to develop future climate scenarios that respond to the needs of local policy-makers.

Photo: B. Tremblay

• Update the recent and future climate profile of Nunavik as well as its hydroclimate and bioclimate sub-components.

• Analyze the impact of climate change on vegetation and large animals.

• Analyze alternative datasets available to characterize the baseline climate and select the most appropriate one;

• Acquire and analyze regional climate simulations available for the Nunavik area;

• Calculate priority climate indicators from baseline and future datasets;

• Calculate recent and future bioclimate classes using the Litynski method;

• Validate and document hydrological indicators available in the cQ2 project;

• Map the results and put together an atlas including all climate, bioclimate and hydrological elements under study;

• Evaluate patterns of vegetation evolution under future climate scenarios;

• Model the current and potential future distribution of migratory caribou, black bear and grey wolf.

The work carried out confirms that Nunavik will undergo major disruptions in climate over the coming decades. Significant overall warming is expected over the 2046-2060 and 2076-2100 horizons, which will result in considerable changes in a number of temperature-related indicators. Likewise, annual precipitation will increase across the entire territory with greater increases during the autumn and winter months.

Overall snow cover will decrease, with a reduction in snowpack duration and maximum depth. With regard to hydrology, it is very likely that average annual flow and average flood flow will increase in the future, for all watersheds under study.

In addition to the final report, a total of 81 climate indicators (Table 1), at annual and monthly scales, were defined and classified into three groups: temperature-related indicators (32 indicators), precipitation-related indicators (19 indicators), and indicators related to solid precipitation and snow cover (30 indicators). For example, Figure 1 below presents the results obtained for growing season length for the 1980-2004 period and under future scenarios (median, high-case and low-case) on the 2076-2100 horizon (RCP 8.5).

This indicator is likely to change significantly, with the regional average increasing from 117 days in the early 2000s to 177 days by the end of the century. The low-case and high-case scenarios strongly agree on the direction of change, as season length increases across the entire territory, regardless of which simulation is used.

Growing season, temperature and average annual precipitation were used to calculate the bioclimate classes of Nunavik, using the Litynski method for classifying the world’s climates.

Figure 1: Growing season length for the 1980-2004 period and future scenarios (median, high-case and low-case) over the 2076-2100 horizon (RCP 8.5)

The results for the 2076-2100 horizon (RCP 8.5) suggest major changes in bioclimate across the region. Indeed, the main findings point to the appearance of certain climate classes, such as “Subpolar” (extremely likely), “Mild Subpolar” (likely) and “Long Growing Season” (extremely likely). On the other hand, other classes may disappear, such as “Polar” (likely) and “Semi-Arid” (extremely likely).

As for changes in vegetation, it appears unlikely that the latitudinal treeline limit will advance significantly by 2100. The greatest impact will probably be seen further south, at the altitudinal limit of forest tundra. In the Arctic tundra zone, the main response to climate change will be a major expansion of the area occupied by upright shrub tundra to the detriment of that covered by prostrate shrub tundra.

Finally, the climate envelope for migratory caribou of the Rivière-aux-Feuilles caribou herd is expected to decrease during the 21st century, for all seasons. While that will not necessarily result in a reduction in the actual distribution range of the herd, it suggests that the predicted changes in climate will exert a negative pressure on individuals in this herd.

Table 1: List of indicators available for the reference climate over future periods 2040-2064 and 2076-2100 under the RCP 4.5 and RCP 8.5 scenarios.

• Centre d’études nordiques/Arcticnet

• Consultants privés

• Ministère de la Forêt, de la Faune et des Parcs (MFFP)

• Université du Québec à Rimouski