Climate Change Impacts on the Prairies

Impacts of Climate Change 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. Rapid 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 dramatically during the winter compared to the summer. There is high confidence that the number of cooling degree days (temperature above 18°C) will increase while the number of heating degree days (temperature below 18°C) will decrease. Mid-winter thaws will become more frequent; winter days below -30°C will become less frequent; and overall winters across the Prairies will continue to get warmer and shorter on average. In the summer, heat waves and heat extremes will increase in frequency. Further, it is expected that the number of frost-free days and growing degree days will increase.

Future projections related to changes in precipitation are less certain, but they commonly suggest that there will be an increase in average annual precipitation levels. However, precipitation levels will vary by season, with fall, winter and spring 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 and wetter winters and springs. More intense rainstorms are likely as temperatures rise and create 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.

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Potential Changes by Eco-Region

Changes in temperature, precipitation patterns and other climatic factors will vary across the Prairies. The bio-physical implications of a changing climate differ by eco-region.

The Prairies

  • Increase in the possibility that droughts will be longer and more frequent.
  • Summer storms are 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.
  • A northward shift of the boundary where grassland meets parkland or forest is expected to occur.
  • 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 as more intense rainfall events result in greater runoff that increases nutrient loads in local water systems.
  • Higher summer temperatures could increase the massive algae blooms in Prairie lakes.

Boreal Forest

  • 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 a longer ice-free season on lakes and rivers and increase the chances of survival of insects like the mountain pine beetle.

The North

  • 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.

Potential Sectoral Impacts of Climate Change

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 they will be felt differently across the Prairie provinces.

 

Agriculture:

  • Warmer and longer growing seasons could be positive for the growth and yield of some new or existing crops, such as corn, and negative for other crops.
  • Shorter and milder winters may put less stress on livestock.
  • Abundance and distribution of various weeds, pests and diseases—both positive and negative—will be influenced by climate change. Exotic species are expected to arrive.
  • Wetter springs and greater potential for floods, as well as hotter, drier summers with more potential for drought, could adversely affect crop and livestock production as well as create expensive challenges for provincial safety net programs.

Forestry:

  • More frequent and severe insect outbreaks, such as of the mountain pine beetle, could occur.
  • Forest fires are expected to be more frequent, of higher intensity and burn over larger areas.
  • Increased tree mortality in the southern margin of the boreal forest as a result of the interaction of insects, drought and fire, leading to the expansion of aspen parklands and grassland ecosystems.
  • Northward expansion and changes in species composition could alter the structure and function of the boreal forest.

Mining:

  • Drought conditions leading to reduced water levels and intake could affect production.
  • Warmer winters could lead to winter road closures, resulting in additional costs.
  • Extreme weather events such as flooding and forest fires could isolate mining operations from people, goods and services as well as increase health and safety concerns.
  • Changes in precipitation patterns and overland flooding may affect waste containment structures (tailing ponds), potentially leading to their failure to prevent contamination of land, surface water and groundwater, and harm to species, habitats and ecosystems.

Transportation and Infrastructure:

  • Increased damage to southern roads, railways and other structures as a result of flooding, erosion and landslides.
  • Continuing loss of winter roads; reports already show decreased ice thickness, poor ice texture and density, delayed winter road seasons and decreased load limits, which leads to higher costs for communities to transport goods and services, as well as greater social isolation.
  • The longer ice-free season in Hudson Bay and northern channels will increase opportunities for ocean-going vessels to use the Port of Churchill.
  • Due to continued permafrost degradation, northern railways (such as the rail line serving Churchill) will require more frequent repair, if not replacement.
  • Permafrost degradation will also affect northern roads, airstrips and building foundations.

Energy:

  • Loss of oil and natural gas production due to more frequent excess moisture and flood conditions, limiting access to production and distribution facilities.
  • Drought conditions could create conflicts between the energy sector and other water users.
  • Annual average streamflows are projected to increase and the timing of runoff will be subject to seasonal shifts within the Nelson–Churchill watershed for the 2050s time period, potentially resulting in higher electricity generation capacities.
  • Seasonal differences due to warming temperatures will have a counteracting effect on total annual electricity energy demand, projecting a decrease in winter demand and an increase in summer demand.

Fisheries and Biodiversity: 

  • Warming surface water temperatures will exacerbate the presence of blue-green algae blooms, potentially affecting commercial fisheries.
  • Geographic ranges of plants and wildlife are expected to move northward; as species have varying capacities to migrate, losses in ecosystem function are expected.
  • Reduced habitat for endangered species like woodland caribou and polar bears.
  • Conditions will become more favourable for some diseases and invasive species, putting more pressure on native species.
  • A longer fall will delay the onset of winter conditions and start of winter recreational activities (e.g., skiing, snowmobiling), while longer, warmer summers may increase opportunities for summer activities (e.g., cottages, camping, boating). These changes have implications for the tourism industry and seasonal businesses.

Health:

  • Populations particularly vulnerable to the consequences of a changing climate are children, the elderly, Indigenous Peoples, the poor, the homeless and people with chronic health conditions.
  • Increased frequency of wildfires may result in increases in respiratory problems.
  • Warmer temperatures will lead to heat-related illnesses and enhance the production of secondary pollutants, including ground-level ozone.
  • Climate-sensitive diseases such as Lyme and West Nile are moving northward and already are present in the Prairies. They are expected to continue to expand their range.

People and Communities:

  • Increased cost of operations such as snow removal, street repairs, storm drains and flood protection measures, along with greater disruption of normal municipal functions, are possible, particularly during extreme weather events.
  • Asphalt, concrete and other hard surfaces in the city absorb radiation from the sun, exacerbating heat waves. Warmer conditions are expected to put greater pressure on the healthcare system and on electricity generation and distribution systems.
  • Small communities largely dependent on well water or smaller reservoirs are at greater risk as drought intensifies or increases in frequency.
  • Declines or uncertainties in the availability of moose, caribou, deer and fish will increase Indigenous communities’ dependence on imported foods and could exacerbate existing food insecurities and health concerns.
  • More severe extreme weather events will affect the bottom lines of insurance companies and may lead to higher insurance premiums or refusal of insurance.
  • Codes, standards and other instruments will have to be adjusted to accommodate changes from historical climate norms, with implications for engineers and planners as part of infrastructure design, operation and maintenance.

“Adaptation to climate change is any activity that reduces the negative impacts of climate change and/or takes advantage of new opportunities that may be presented.”

Sources

The content for this section draws upon the following sources: