K-2 Chapter 2. How Does Climate Change Affect Our World?
Regions across Canada are already experiencing the effects of climate change. Many ecosystems are changing rapidly, and animals’ habitats are changing at a faster rate than they can adapt. The Living Planet Report shows an average decline of 60% in animal populations between 1970 and 2014. In order to conceptualize some of the major environmental effects that can be attributed to climate change and trends that could emerge in coming years, the effects have been broken down into the following sub-categories: changes in temperature and precipitation, changes to the cryosphere (portions of Earth’s surface where water is in solid form, including ice caps, glaciers, sea ice, snow cover, etc.), changes to freshwater resources, changes to ocean climate, and biodiversity changes.
Changes in Temperature and Precipitation:
- In Canada, temperatures have increased by 1.5 degrees above pre-industrial levels. Canada’s position in the far northern hemisphere means that we are experiencing the effects of climate change at a higher rate than many other regions in the world.
- Warmer air has the potential to absorb more surface water, resulting in both droughts and more intense precipitation events. Overall trends indicate that Canada has become wetter in the past decade, with increased rainfall and decreased snowfall across many regions of southern Canada.
- Temperature and weather extremes are expected (very hot and very cold as well as very wet and very dry) leading to a higher risk of associated environmental hazards such as floods and droughts.
- Overall temperature warming is enhanced in the northern latitudes of the country.
Changes to the Cryosphere (parts of the earth’s surface characterised by the presence of frozen water)
- Permafrost temperatures in Northern Canada have been consistently rising 0.2 degrees per decade over the past 20-30 years.
- Globally between 2007 and 2016, there has been an average increase of 0.29°C ± 0.12°C in permafrost temperatures.
- The effects of melting permafrost include the release of harmful greenhouse gases previously trapped within the ice and the reduction of structural support in regions previously covered by permafrost.
- Glaciers have been melting at an accelerated rate since the beginning of the 20th century—glaciers lost 11% and 25% of their surface area in Alberta and British Columbia, respectively, between 1985 and 2005 Columbia, respectively, between 1985 and 2005 (Canada in a Changing Climate: Sector Perspectives on Impacts and Adaptation; Chapter 2, 2014).
- Changes to freshwater resources across Canada are difficult to categorize as a whole due to the extreme regional variation that exists.
- Canadian data shows that water quality has remained stable in the vast majority of monitoring stations across the country (81%) between 2002 and 2016, improved in 10% of locations, and decreased in 9%.
- However, the levels of PBDEs (Polybrominated diphenyl ethers, persistent organic pollutants) remain above prescribed guidelines in the following locations: The Great Lakes, Pacific Coastal, and St. Lawrence.
- Excessive nutrients in both the Winnipeg River Basin and The Great Lakes area have caused detrimental algae blooms in these locations.
- Water levels across the Great Lakes (the largest surface freshwater system on Earth) broke seasonal or all-time record highs in both 2019 and 2020. These changes in water level are a wake-up call that these types of extreme conditions are not a worry for the future, but happening now. “Adaptation planning must manage uncertainty, rather than try to avoid it” (Kwakkel et al., 2016 – from NRCAN National Issues Report, Chapter 4)
- “Combined changes in precipitation phase (e.g., rain or snow), earlier snowmelt, ice cover retreat and decreasing glacier mass affect Canadian river flows and lake levels. Future trends identified in Canada’s Changing Climate Report (Bush and Lemmen, 2019) and other studies, include: less water availability in southern basins, particularly in summer; increased frequency and intensity of water-related extremes; reduced water quality and more harmful algae blooms.” (NRCAN National Issues Report p. 196-197)
Changes in the Ocean Climate
- Trends in the Pacific, Atlantic and Arctic oceans indicate long-term warming of approximately 0.1 percent per decade, in both surface temperatures and bottom waters.
- Ocean temperature, acidity, and oxygen levels are affected by increasing atmospheric carbon dioxide levels.
- Since the 1980’s the ocean has absorbed between 20-30% of total anthropogenic carbon dioxide emissions.
- The rate of ocean warming has more than doubled since 1993 (IPCC).
- Ocean levels are rising at a concerningly fast rate (in part due to the melting ice caps), which is increasing the risks of flooding and potential contamination of freshwater and groundwater, among other issues.
- In Canada, a country surrounded by three different ocean bodies, the changes to ocean levels, temperature, and composition are of paramount importance.
- “NASA measures sea level around the globe using satellites. The Jason-3 satellite uses radio waves and other instruments to measure the height of the ocean’s surface – also known as sea level. It does this for the entire Earth every 10 days, studying how global sea level is changing over time.”
- For resources explaining the effects of climate change on the oceans to young children visit NASA’s Climate Kids.
Biodiversity changes in Canada:
- Increases in the frequency and intensity of droughts, forest fires, and insect outbreaks in combination with direct human impacts like deforestation, pollution, and overharvesting are resulting in habitat loss and threatening the survival of many species (Canada and a Changing Climate).
- Changes to season lengths and times (such as earlier springs) are changing the growth and reproduction patterns of many plant species, which directly affects animals that rely on them for food and habitat.
- Physical changes in the landscape (e.g., higher water levels or human barriers such as roads, farms, and dams) can prevent animals from accessing food or breeding/rearing areas and can result in habitat loss.
- “The capacity of ecosystems and individual species to adapt to climate change through range shifts, however, is not without limits. Organisms are limited in the range of environments to which they can adapt.” (NRCan p. 284)
- “Since biodiversity is critical to ecosystem resilience and functioning, it is important to consider ecosystem services within the context of broader life support systems when investigating climate change impacts, ecosystem responses, climate change adaptation and greenhouse gas (GHG) emissions reduction (Biodiversity Adaptation Working Group, 2018).” (NRCan p. 278)
Human Impacts & Disproportionate Effects:
Note: Environmental racism and environmental justice can be discussed in age appropriate ways. Suggested Resource to learn more: Environmental racism in Canada: What is it and what can we do about it?).