This Is What Climate Change is Doing to our Fresh Water

Our Air is Getting Warmer

• This is happening even quicker in northern temperate climates (such as in the boreal forest, where IISD-ELA is located). Research from the site has found that, since 1969, mean annual air temperatures have increased by 0.42°C each decade, much faster than the global average (0.15–0.30°C/decade).
• Autumn and winter months are warming much faster than summer months.
• Over the next century, Western Canada will likely become drier and Eastern Canada will become wetter due to increased precipitation.

Our Lakes Are Getting Less Icy

• In many parts of the Northern Hemisphere, researchers have documented shorter winters and shorter periods of ice cover.
• This will continue to happen. Based on regional climate projections for northwestern Ontario, the duration of ice cover is projected to decline by an additional 20–30 days by 2070.
• Why does this matter? The duration of ice cover on lakes is important for winter roads into remote northern communities and recreational activities such as pond hockey and ice fishing. It is also very important to many physical, chemical, and biological processes in lakes.

Our Lakes Are Getting Darker

• Across Europe and many parts of North America, many lakes are getting darker. This is due to many factors, but the main reason is the increased addition of dissolved organic carbon (DOC) entering our lakes with increased precipitation. If you have ever looked into a wetland or lake and seen the dark brown colour of the water, that is DOC.
• In Eastern Canada, climate projections suggest that lakes will get darker, whereas in Western Canada, they will be getting lighter. This is due to different rates of precipitation.
• Why does this matter? Water clarity is an important feature of lakes, determining how much light and heat penetrate the water surface and what sorts of animal and plant life can live and thrive there.

Our Fish Are Squeezing into Smaller Habitats

• Lake trout are being squeezed. This happens because their preferred habitats get squeezed between surface waters that are too hot and bottom waters where dissolved oxygen is too low for the trout to survive.
• This will continue to happen. With increasing global temperatures, we can expect surface lake temperatures to rise, which may start affecting the habitat available to lake trout. If this happens too quickly and the species cannot adapt in time, lake trout near the southern edge of their natural range will likely begin to disappear.

Our Fish Are Getting Smaller

• Lake trout are getting smaller. Scientists at IISD-ELA found that the average length of an adult lake trout (from its snout to the fork in its tail) has decreased since records began way back in the 1970s.
• How does climate change come into this? The decline in the size of lake trout over time is likely related to longer summer periods where fish are stuck in deeper waters with reduced access to food.

• We need more—and better—restoration and management of wetlands to ensure that less water—and the nutrients, such as phosphorus, it stores—leaches into lakes from surrounding areas.
  • This management ranges from more restoration of previously drained wetlands to more innovative natural infrastructure solutions that hold water on the land.

• We need to track the health of more freshwater bodies over extended periods of time.
  • IISD-ELA’s long-term dataset is incredible and unparalleled, but we need more data on the ongoing health of lakes across Canada and the world to build a broader picture of what climate change is doing to our freshwater supplies.
  • We need more resources dedicated to data collection alongside grassroots efforts, such as citizen science programs, that empower individuals to track the health of their local bodies of water.

• We need to support technological solutions that allow us to track the health of freshwater bodies—and analyze this data—all in real time.
  • This is already happening across the country, but we need to see more!

• We need to support the freshwater scientists and hydrologists of the future.
  • A new generation of limnologists will need to take the mantle of tracking the ongoing impacts of climate change on the environment, and they need to be nurtured, supported, and offered opportunities!

• We look forward to the burgeoning Canada Water Agency supporting and coordinating all of these efforts to build a bigger and better picture of the impacts of climate change on Canada’s fresh water across the country for maximum impact.