POTENTIAL IMPACTS OF GLOBAL SEA‐LEVEL RISE ON CANADIAN COASTS

The sea-level rise that may result from global climate change is placed within the context of past and present sea-level changes on Canadian coasts. To assess future impact, a dimensionless index of sensitivity is determined. Coasts with low, moderate, and high sensitivity constitute 67%, 30%, and 3% of the total coastline, respectively. The most sensitive regions are: (1) several parts of the Maritime Provinces; (2) two areas of the British Columbia coast; and (3) a large part of the Beaufort Sea coast. Impacts in four regions - Bay of Fundy, Beaufort Sea, Fraser Delta, and Eastern Shore of Nova Scotia - are discussed in detail. It is argued that the societal response to changes in sea level should favour retreat and accommodation strategies. Il est possible que les changements climatiques globaux provoqueront une elevation du niveau de la mer. Nous examinons ce scenario dans le contexte des changements passes et presents du niveau de la mer sur les cotes canadiennes. Pour evaluer l'impact de l'elevation prevue un indice non dimensionnel de vulnerabilite est determine. Les cotes a la vulnerabilite basse, moderee et elevee constituent, respectivement, 67%, 30%, et 3% de tout le littoral. Les regions les plus vulnerables sont: (1) plusieurs regions dans les provinces maritimes; (2) deux zones sur la cote de la Colombie britannique; et (3) la plupart de la cote de la mer de Beaufort. Nous discutons en detail les impacts dans quatre regions, soit la baie Fundy, la mer Beaufort, la delta du Fraser et la rivage dit ‘Eastern Shore’ de la Nouvelle-Ecosse. Nous estimons que la reponse sociale aux changements du niveau de la mer devrait favoriser des strategies de retraite et d'accommodement.

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