Sea Level Rise

The map below shows the sensitivity of the coastlines of Atlantic Canada to the expected rise in sea level, due to climate warming. Sensitivity here means the degree to which a coastline may experience physical changes such as flooding, erosion, beach migration, and coastal dune destabilization. It is measured by a sensitivity index that is obtained by manipulating scores of 1 to 5 attributed to each of seven variables: relief, geology, coastal landform, sea-level tendency, shoreline displacement, tidal range, and wave height. For details on the index refer to J. Shaw, R.B. Taylor, D.L. Forbes, M.-H. Ruz, and S. Solomon. 1998. Sensitivity of the Coasts of Canada to Sea-level Rise. Geological Survey of Canada Bulletin 505. Ottawa.

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Regions of high sensitivity include much of the coasts of Nova Scotia, Prince Edward Island, and New Brunswick. Small areas of high sensitivity occur in Newfoundland and Labrador.

The full map for Canada can be viewed in an interactive viewer that can zoom in and out at Natural Resources Canada's Atlas of Canada Site.

Global sea level rise is influenced by two major processes, thermal expansion as ocean temperatures rise and the transfer of water from snow and ice reservoirs e.g. glaciers to the ocean.

In addition as seen on the map in purple hatching, in almost all of Atlantic Canada, regional sea level is influenced by submergence caused by glacial isostatic adjustment (i.e. the process whereby the Earth's shape is modified in response to the large scale changes in surface mass load that have attended the glaciation and deglaciation of the planetary surface. The last deglaciation event ended approximately 5000 years ago.)

In recent years there has been considerable change in the level of future global sea level researchers have been projecting.

One of the most recent reports (October 2009) published by the Government of New South Wales in Australia (Derivation of the NSW Government’s sea level rise planning benchmarks) estimates an increase in global sea level of 30 cm by 2050 and 59 cm by 2100. If the impact of potential accelerated ice melt is included the 2100 number increases by 20 cm. The report uses numbers in the upper range of predictions which can be considered wise due to the uncertainty in these predictions.

Batterson and Liverman (2010) project between 30 and 40 cm rise in sea level in Newfoundland and Labrador by 2049 and 70 cm to more then 100 cm on the Avalon Pennisula by 2100.

The Province of Nova Scotia’s State of the Coast report states “Researchers expect an additional increase [in sea level] from 70 to 140 cm over the next century.”