Climate Change Impacts on the Canadian Prairies
The Canadian Prairies are recognized internationally as a potential climate change “hotspot” due to their relatively high latitude and location in the middle of the continent. In the coming decades the Prairie’s summers are projected to become warmer and drier and winters and springs warmer and wetter. Precipitation is likely to be characterized by greater variability and uncertainty from year to year, and within each year. Swings between wet and dry conditions could become more common. Extreme weather events such as heat waves, droughts, floods and intense storms are projected to increase in intensity and frequency. Overall, the climate is going to become even more variable, and less predictable.
Average temperatures will increase much more dramatically during the winter compared to the summer. There is high confidence that the number of cooling-degree days (temperature above 18 Celcius) will increase while the number of heating-degree days (temperature is below 18 Celcius) will decrease. Mid-winter thaws will become more frequent, winter days below -30 Celcius will become less frequent, and overall winters across the Prairies will continue to get warmer and shorter. In the summer, heat waves and heat extremes will increase in frequency. Further, it is expected that the number of frost-free and growing-degree days will increase.
Future projections related to changes in precipitation are less certain, but commonly suggest that there will be an increase in average annual precipitation levels. However, precipitation levels will vary by season, with fall, winter and springs expected to become wetter while summer precipitation levels are likely to remain the same or decline.
A greater risk of extreme events is projected. The risk of spring flooding may increase with warmer, wetter winters and springs. More intense rainstorms are likely as temperatures rise, creating a more energetic climate. Static or declining precipitation levels in combination with high temperatures (and associated increases in evapotranspiration), could potentially lead to more drought conditions in the summer.
Changes in temperature, precipitation patterns and other climatic factors will vary across the Parries. The bio-physical implications differ by eco-region:
- Increase in the possibility that droughts will be longer and more frequent.
- Summer storms likely to be more intense and numerous as temperatures increase, leading to more erosion, stream sedimentation and potential for flash flooding.
- Longer, hotter growing seasons will increase the potential for pests and invasive species.
- Northward shift of the boundary where grassland meets parkland or forest.
- In some regions warmer temperatures may result in more precipitation falling as rain in the winter and spring, leading to less snowpack accumulation and increased streamflow. Other regions could experience higher snowfalls.
- On average, lower streamflow is likely to occur in the summer due to higher temperatures and lower precipitation; however, the future will likely also experience greater variability in streamflow due to larger singular rainfall events that overwhelm local drainage, leading to more flash flood like conditions.
- Greater potential for eutrophication of water bodies with more intense rainfalls increasing nutrient loads in local water systems.
- Higher summer temperatures could increase the massive algae blooms in Prairie lakes.
Northern boreal forest area:
- More lightning combined with drier conditions could cause more intense and frequent forest fires.
- Southern forest regions could see a general reduction in tree growth, regeneration failure in dry years, and a gradual reduction in tree cover, allowing northward expansion of grassland patches and changes in the composition of trees.
- Boreal forest wildlife and plant species are projected to move northwards leading to disruptions of current boreal communities.
- Increased average winter temperatures will lead to longer ice-free season on lakes and rivers, and increase the chances of survival of insects like the mountain pine beetle.
- The extent of continuous and discontinuous permafrost (ground that remains frozen throughout the year) will decline as the ground warms and becomes soft and uneven, with implications for hydrologic conditions, species habitat, building foundations and transportation corridors.
- Potential large scale melting of permafrost peatlands could release significant amounts of stored carbon into the atmosphere, further driving the process of climate change.
- Longer ice freeze season along the Hudson Bay coastline.
Even if there is a significant reduction in global greenhouse gas emissions, the Prairies will experience significant changes in its climate by the end of the 2080s. These changes have a range of potential implications—both positive and negative—for different sectors and groups, and will be felt differently across the Prairie provinces. Follow the link below to find illustrative examples of how climate change is expected to impact different economic sectors as well as its implications for different groups of peoples and communities.
Short videos from the Canadian Foundation of Climate and Atmospheric Science explaining climate change impacts in the Prairies
Canadian Prairies Drought
Western Canadian Glaciers under Climate Change
Water - The Oil of the 21st Century
The content for this section draws upon the following sources:
From Impacts to Adaptation: Canada in a Changing Climate (2008) assesses risks and opportunities presented by climate change, and actions being taken to address them, from a regional perspective.
Prairie Climate Centre. (2016). Prairie Climate Atlas.
Natural Resources Canada. (2014). Canada in a Changing Climate: Sector Perspectives on Impacts and Adaptation. Government of Canada.
Sauchyn, D., Diaz, H. and Sulshreshtha, S (eds.) (2010). The New Normal: The Canadian Prairies in a Changing Climate. Regina: Canadian Plains Research Centre.
Prairie Adaptation Research Collaborative (PRAC). (2008). Climate Change Impacts on Canada’s Prairie Provinces: A Summary of our State of Knowledge. Summary Document.
IISD. (2007). Climate Change Impacts in Manitoba. Retrieved from https://www.iisd.org/sites/default/files/publications/com_climate_impacts_mb.pdf