Module 1: Physical Risks
Changing Climate – Changing Risk
It may surprise you to learn that Germanwatch’s Climate Risk Index for 2020 ranks Canada as the country 9th most affected by climate change in the world! According to Environment Canada, Canada is warming at twice the global rate on average, and between 3 – 4 times the global rate in parts of western and northern Canada.
The table below summarizes the major projected changes in Canada’s climate:
Projected changes in Canada’s Climate
| Temperature | |
| Seasonal temperature | The largest increases in air temperature are projected for northern Canada in winter. In summer, the largest increases are projected for southern Canada and the central interior. The magnitude of projected warming varies substantially by emission scenario. |
| Extremes in daily temperature | Increases in the frequency and magnitude of unusually warm days and nights, and decreases in unusually cold days and nights, are projected to occur throughout the 21st century. |
| Long-duration hot events | The length, frequency, and/or intensity of warm spells, including heatwaves, are projected to increase over most land areas. |
| Rare hot extremes | Rare hot extremes are projected to become more frequent. For example, a 1-in-20 year extreme hot day is projected to become about a 1-in-5 year event over most of Canada by mid-century. |
| Precipitation and Other Hydrological Indicators | |
| Seasonal precipitation | Increases in precipitation are projected for the majority of the country and for all seasons, with the exception of parts of southern Canada, where a decline in precipitation in summer and fall is projected. |
| Heavy precipitation | More frequent heavy precipitation events are projected, with an associated increased risk of flooding. |
| Rare precipitation events | Rare extreme precipitation events are currently projected to become about twice as frequent by mid-century over most of Canada. |
| Streamflow | Increases in winter streamflow are projected for many regions in southern Canada. Mean annual streamflow is projected to decrease in some regions of Alberta and Saskatchewan, while projections for other regions vary across different scenarios. |
| Snow Cover | |
| Snow-cover duration | Widespread decreases in the duration of snow and ice cover are projected across the Northern Hemisphere, with the largest changes in maritime mountain regions, such as the west coast of North America. |
| Snow depth | Maximum snow accumulation over northern high latitudes is projected to increase in response to projected increases in cold-season precipitation. |
| Permafrost | |
| Ground temperature | Warming of the permafrost is projected to continue at rates surpassing those observed in records to date. Because much of the Arctic permafrost has a low average temperature, it will take many decades to centuries for colder permafrost to completely thaw. |
| Sea Level | |
| Global sea-level rise to 2100 | Estimates of the magnitude of future changes in global sea level by the year 2100 range from a few tens of centimetres to more than a metre. |
| Global sea-level rise beyond 2100 | Projections beyond 2100 indicate continuing global sea-level rise over the coming centuries and millennia. Global sea-level rise may eventually amount to several metres. |
| Relative sea-level change | Patterns of change along Canadian coastlines will continue to be influenced by land uplift and subsidence as well as by changes in the oceans. Sea-level rise will continue to be enhanced in regions where the land is subsiding, and sea level is likely to continue to fall in regions where the land is rapidly rising. Regions where the land is slowly rising may experience a transition from sea-level fall to sea-level rise. |
| Sea-Ice Extent | |
| Arctic summer sea ice | A nearly ice-free summer is considered a strong possibility for the Arctic Ocean by mid-century, although summer sea ice may persist longer in the Canadian Arctic Archipelago region. |
| Lake Ice | |
| Ice-cover duration | With the continued advance of ice cover break-up dates and delays in ice-cover freeze up, ice-cover duration is expected to decrease by up to a month by mid-century. |
Reproduced from Warren & Lemmen (2014) in The Expert Panel on Climate Change Risks and Adaptation Potential. (2019). Canada’s top climate change risks. Council of Canadian Academies. You can read the full report here.
For an overview of global climate trends and risks, read Section 2 A changing climate and resulting physical risks (pp. 48 – 59) in Woetzel, J., Pinner, D., Samandari, H., Engel, H., Krishnan, M., Boland, B., & Powis, C. (2020). Climate risk and response: Physical hazards and socioeconomic impacts. McKinsey Global Institute.