|Title||Changes in oceans surrounding Canada|
|Author||Greenan, B J W; James, T S; Loder, J W; Pepin, P; Azetsu-Scott, K; Ianson, D; Hamme, R C; Gilbert, D; Tremblay, J -E; Wang, X L; Perrie, W|
|Source||Canada's changing climate report; by Bush, E (ed.); Lemmen, D S (ed.); 2019 p. 343-422|
|Links||Online - En ligne|
|Alt Series||Natural Resources Canada, Contribution Series 20180242|
|Publisher||Government of Canada|
|Media||paper; on-line; digital|
|Related||This publication is contained in Bush, E; Lemmen, D S;
(2019). Canada's changing climate report|
|Related||This publication is a translation of Greenan, B J W;
Greenan, B J W; James, T S; James, T S; Loder, J W; Loder, J W; Pepin, P; Pepin, P; Azetsu-Scott, K; Azetsu-Scott, K; Ianson, D; Ianson, D; Hamme, R C; Hamme, R C; Gilbert, D; Gilbert, D; Tremblay, J -E; Tremblay, J -E; Wang, X L; Wang, X L; Perrie,
W; Perrie, W; (2019). Changements touchant les océans qui bordent le Canada, Rapport sur le climat changeant du Canada|
|File format||pdf (Adobe® Reader®)|
|Province||Canada; Offshore region; Northern offshore region; Western offshore region; Eastern offshore region; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia;
Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut|
|NTS||1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 24; 25; 26; 27; 28; 29; 32; 33; 34; 35; 36; 37; 38; 39; 42; 43; 44; 45; 46; 47; 48; 49; 54; 55; 56; 57; 58; 59; 66; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88;
89; 92; 93; 97; 98; 99; 102; 103; 104; 107; 114O; 114P; 115; 117; 120; 340; 560|
|Area||Atlantic Ocean; Pacific Ocean; Arctic Ocean; St. Lawrence Estuary; Gulf of St. Lawrence; Bay of Fundy; Hudson Bay; Baffin Bay; Labrador Sea; Gulf of Alaska; Strait of Georgia|
|Lat/Long WENS||-141.0000 -50.0000 90.0000 41.7500|
|Subjects||Nature and Environment; marine geology; environmental geology; climatology; climate; climate effects; oceanography; oceanographic surveys; coastal environment; coastal management; coastal erosion;
currents; water circulation patterns; sea water geochemistry; salinity; densities; brine; storms; sea level changes; isostasy; crustal uplift; floods; acidity; carbon geochemistry; oxygen geochemistry; water temperature; continental margins; fiords;
climate change; oceans; wind; waves; geological hazards; nutrients|
|Illustrations||geoscientific sketch maps; location maps; time series; tables; photographs; schematic representations|
|Program||Coastal Infrastructure, Climate Change Geoscience|
|Released||2019 04 02|
The global ocean covers approximately 71% of the Earth's surface and is a vast reservoir of water, energy, carbon, and many other substances. It is a key component of the climate
system and interacts directly with the atmosphere and cryosphere. Freshwater resources are also linked to the ocean via runoff in coastal areas. The ocean plays an important role in mitigating anthropogenic climate change through its ability to
absorb substantial amounts of heat and carbon.
Canada is surrounded by oceans on three sides - the Pacific, Arctic, and Atlantic oceans. There is strong evidence of human-induced changes during the past century in key ocean-climate properties -
such as temperature, sea ice, sea level, acidity, and dissolved oxygen - off Canada. Warmer ocean temperature has contributed to declining sea ice and increasing sea level. However, there is an area south of Greenland where there has been little
ocean warming, so regional trends do differ. Warming and a slight freshening of the upper ocean have reduced its density resulting in increased vertical differences in density (referred to as “density stratification”) in oceans off Canada; this could
affect the vertical transport of heat, carbon, and nutrients and, thereby, ecosystem health and services.
Global sea levels are rising due to ocean thermal expansion, and diminishing glaciers and ice sheets which deliver water to the oceans.
Changes in sea level relative to Canada's coastline are also affected by vertical land motion (upward, called “uplift” or downward, called “subsidence”) in response to the retreat of the last glacial ice sheet. Relative sea level has increased in
most regions of Canada over the last century and even exceeded the global rate of change in southern Atlantic Canada, where land is subsiding. However, there are regions of Canada (e.g., Hudson Bay) where relative sea level has fallen as a result of
the rate of uplift being higher than the rate of global sea-level rise. Increasing relative sea level is also increasing risks for coastal infrastructure and communities. This is compounded by increases in ocean wave heights in areas that have
experienced seasonal reductions in sea ice.
Ocean chemistry has undergone changes, such as increasing acidity and decreasing subsurface oxygen concentrations, as a result of anthropogenic climate change. The physical and chemical trends observed
in the oceans surrounding Canada are consistent with changes observed in the atmosphere, cryosphere, freshwater systems, and adjoining oceans.
The fundamental principles that govern how the physical and chemical environment of the ocean will
respond to increased atmospheric carbon dioxide have allowed model-based projections of future conditions in the oceans surrounding Canada under a range of emission scenarios. In general, warming and freshening at the ocean surface is projected
during this century, which will continue to increase stratification and reduce sea ice. Sea-level rise along some Canadian coastlines will be higher than the global average during this century, leading to increased flooding and erosion. Ocean
acidification and decreasing subsurface oxygen levels will continue, with increasingly adverse implications for marine ecosystems.
|Summary||(Plain Language Summary, not published)|
Global sea level is projected to rise through the century, but the sea-level change experienced on Canada's coasts could rise or fall, depending on the
magnitude and sign of vertical land motion. Sea-level on Canada's coasts is projected to rise for most of the Atlantic and Pacific coasts and the Beaufort coast of Arctic Canada. Where sea-level is projected to rise, an increase in the frequency and
magnitude of high-water events is anticipated. An increase in extreme high-water events is also anticipated in regions where sea-ice extent and duration is expected to decrease in Atlantic and Arctic Canada.