How will this affect you?

Canada Country Studies: A Window on Climate Change in Canada

Climate change projections suggest that over the next century, further warming of 1° to 3.5° C will occur. Based on this scenario, the Canada Country Study found that the implications of climate change for water resources are a key to defining overall impacts for all sectors and regions of the country.

Overall, the impacts of climate change on our forests, fish populations, and agriculture could be extreme.

They include:

• longer growing seasons and extension of agriculture further north, but also risks to agriculture such as moisture deficits, pests, disease, and fires;
• impacts on fish populations, which could increase in some areas, mostly in the Arctic and on northern areas of the Pacific coast, and decrease in others, particularly the lakes and rivers of the Canadian Shield;
• effects on hydroelectric generating potential, with increases in Labrador and Northern Quebec, and lower potential in Ontario, the Prairies, and southeastern B.C.;
• risks to waterfowl populations due to lower water levels in lakes, rivers, and wetlands; and
• projected changes in the occurrence and severity of extreme events, which would have serious implications for the security and integrity of Canada's natural resources, social systems, and infrastructure with subsequent implications for the insurance industry and supporting public sectors.

In looking at the impacts for Canada, the study drew upon 26 component reports covering six regions of Canada and 20 sectoral and related issues of socio-economic significance. Highlights of the regional reports are included here. It is important to bear in mind those uncertainties regarding the character, magnitude, and rates of future climate change remain. These uncertainties impose limitations on the ability of scientists to project impacts of climate change, particularly at the regional and smaller scales.

British Columbia/Yukon

Climate change will have significant impacts on British Columbia and Yukon, including increased flood dangers in some areas, drought in others, and widespread disruption to forests, fisheries, and wildlife.

Sea levels are expected to rise up to 30 cm on the north coast of British Columbia and up to 50 cm on the north Yukon coast by 2050, mainly due to warmer ocean temperatures. This could cause increased sedimentation, coastal flooding, and permanent inundation of some natural ecosystems, and place low-lying homes, docks, and port facilities at risk.

Other changes that may result from climate change include:

In winter, increased winter precipitation, permafrost degradation, and glacier retreat due to warmer temperatures may lead to landslides in unstable mountainous regions, and put fish and wildlife habitat, roads, and other man-made structures at risk. Increased precipitation will put greater stress on water and sewage systems, while glacier reduction could affect the flow of rivers and streams that depend on glacier water, with potential negative impacts on tourism, hydroelectric generation, fish habitat, and lifestyles.

Spring flood damage could be more severe both on the coast and throughout the interior of British Columbia and Yukon, and existing flood protection works may no longer be adequate.

Summer droughts along the south coast and southern interior will mean decreased stream flow in those areas, putting fish survival at risk, and reducing water supplies in the dry summer season when irrigation and domestic water use is greatest.

Prairies

Current models suggest that climate change could result in increased air temperatures and decreased soil moisture. There is less confidence about whether precipitation will increase or decrease or about how climate change may affect severe weather events. Most scenarios suggest that the semi-arid regions of the Prairies can expect an increase in the frequency and length of droughts.

Some of the potential impacts of these changes include:

Average potential crop yields could fall by 10-30 per cent, due to higher temperatures and lower soil moisture. However, higher temperatures could lengthen the growing season, and may increase crop production in northern regions where suitable soils exist.

Increased demand for water pumping and summer cooling, due to drought, and decreased winter demand due to higher temperatures, could push electrical utilities into a summer peak load position at the same time as hydropower production is reduced by decreased water flow. This could result in increased thermal power production with an increase in fossil fuel consumption and greenhouse gas emissions.

Semi-permanent and seasonal wetlands could dry up, leading to reduced production of waterfowl and other wildlife species.

Arctic

In the past 100 years, the Mackenzie district has warmed by 1.5° C and the Arctic tundra area by 0.5°, while the Arctic mountains and fjords of the eastern Arctic have cooled slightly. Future winter temperature increases of 5-7° degrees over the mainland and much of the Arctic Islands and modest cooling in the extreme eastern Arctic are projected. Summer temperatures are expected to increase up to 5° degrees on the mainland, and 1-2° degrees over marine areas. Annual precipitation is expected to increase up to 25 per cent.

These changes in temperature and precipitation would have dramatic effects on tundra and taiga/tundra ecosystems, reducing them by as much as two thirds of their present size. More than one half of the discontinuous permafrost area could disappear, with marked surface instability in the short term.

Wildlife would also be affected, with many species in fish and streams shifting northward 150 km for each degree increase in air temperature and High Arctic Peary caribou, muskoxen, and polar bears running the risk of extinction.Climate change would also extend the shipping season in the Arctic, while rising sea levels in the Beaufort Sea areas would endanger coastal infrastructure.

Ontario

Ontario could experience anywhere from 3-8° degrees C average annual warming by the latter part of the 21st century, leading to fewer weeks of snow, a longer growing season, less moisture in the soil, and an increase in the frequency and severity of droughts.

Other impacts of climate change could include:

• more days when heat stress and air pollution adversely affect people's health;
• likely increases in the frequency and severity of forest fires; and
• changes to aquatic ecosystems and alterations to wetlands.

As well, water levels in the Great Lakes could decline to record lows by the latter part of the 21st century, reducing shipping capacity.

Quebec

If carbon dioxide levels were to double, Quebec would experience average temperature increases of 1-4° C in the south and 2-6° degrees in the north. Precipitation would likely remain the same or decrease slightly in the south, while increasing 10-20 per cent in the north.

Likely consequences include:

• lower water levels in the St. Lawrence River, which will affect shipping, navigation, and the marine environment of the river; and
• positive effects on agriculture, including a longer growing season and the extension of agriculture further north.

Atlantic

Climate change in the Atlantic region has not followed the national warming trend of the past century, and, in fact, a slight cooling trend has been experienced over the past 50 years. This trend is consistent with projections by climate models.

Atlantic Canada is particularly vulnerable, however, to rising sea levels, whose impacts could include greater risk of floods; coastal erosion; coastal sedimentation; and reductions in sea and river ice.

Other potential impacts include:

• loss of fish habitat;
• changes in ice-free days, which could affect marine transportation and the offshore oil and gas industry; and
• changes in range, distribution, and breeding success rates of seabirds.