One of the fastest-warming regions on Earth, the Arctic may face the worst impacts of climate change. Scientists predict widespread melting of Arctic sea ice — a vast, frozen platform that has already thinned by 40 percent in recent years.
Vital to the survival of walruses, king eiders, narwhals, arctic char, and many other species, sea ice also serves as a travelling route for muskoxen, caribou, and arctic foxes and as a hunting ground for the Inuit. Algae living underneath the sea ice are the foundation of a food web that supports plankton, copepods, molluscs, sea birds, fish, and mammals.
Among the species affected most is the black guillemot, a sea bird whose populations have plunged since 1990 as the lack of sea ice increases the distances it must fly to forage for food. Likewise, the polar bear faces the loss of the frozen habitat it needs to hunt ringed seals, its principal prey.
Higher temperatures in the Pacific Region could result in rising sea levels, coastal flooding, diminished stream flow, repeated cycles of flooding and drought, and habitat loss on land and at sea. Warmer ocean temperatures could result in shifts in the ranges and food supplies of many species, from sea otters to sockeye salmon. Rising sea levels could threaten such coastal zones as the Fraser River delta with floods and erosion. More rain and snow could cause flooding throughout the interior.
Extremes of climate and altitude make the Western Mountains particularly sensitive to rising temperatures and increasing precipitation. Deep snow could make it difficult for animals like deer and elk to forage for food. The rapid melting of low-level glaciers could result in landslides that damage wildlife habitat. Meanwhile, plants and animals may move upward from below and displace species confined to the highest peaks.
Rising temperatures, decreasing rainfall, greater rates of evaporation, and drier soils in the Prairie Region could cause habitat loss on land and in water. More than half of prairie potholes could disappear due to climate change. These ephemeral wetlands are key breeding habitats and migratory stopovers for Canadian ducks, including mallards, widgeons, and pintails. Their loss would come as a serious blow not only to waterfowl but also to reptiles, amphibians, and mammals.
Drier, warmer weather could transform the Boreal Region, which comprises one-third of the planet's woodlands. The increasing frequency of forest fires and pest infestations, a northward shift in the prairie grasslands, and changes in the composition of tree species could wipe out half of this ecosystem, imperilling pine martens, spruce grouse, boreal chickadees, and countless other creatures.
Great Lakes-St Lawrence Region.
Climatologists predict major changes in the lands and waters of the Great-Lakes-St. Lawrence Region. As the atmosphere heats up, so will lakes, streams, and rivers, and much more water will evaporate. Lake levels could fall by up to a metre, reducing the amount of water flowing through the system. Cold-water fish, such as salmon and trout, and species at risk, like the spotted turtle and swamp rose-mallow, could suffer substantial habitat loss.
The Atlantic Region is particularly vulnerable to coastal erosion, the shrinking of beaches and tidal flats, the flooding of low-lying habitats, and the submersion of barrier islands due to rising sea levels. Coastal wetlands, adapted to a unique mix of fresh and salt water, are most at risk. Heavier rainfall could increase the amount of run-off polluting coastal waters. Changes in ocean temperature could affect the range, distribution, and food supplies of sea birds and marine mammals.
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