Air temperatures on the north portion of Vancouver Island are expected to increase by 2050 to the same range as currently experienced in Vancouver [10,42], which reflects approximately 1.4°C warming relative to a 1960s-1990 baseline. Increasing air temperatures threaten fisheries and aquaculture through associated ocean warming which is likely to affect seasonality of traditional food resources as the summer season extends and frost-free days increase. There are potential benefits to tourism, an important sector in this sub-region, as the summer season lengthens and becomes warmer and more appealing.
Winter precipitation is predicted to increase in this sub-region, leading to increasing spring freshwater discharge that will also contribute to stronger flows in Queen Charlotte Sound [21,42,73]. Increased precipitation and stream discharge will increase flood risk to communities, while decreased summer precipitation will increase drought potential in summer months. Tourism may benefit as summer precipitation levels decrease, potentially attracting foreign visitors to outdoor recreation opportunities. However, winter snowfall is likely to decrease by as much as 33%, which could affect winter tourism and recreation.
Sea level rise projections are quite uncertain at the scale of MaPP sub-regions. Sea level rise will potentially not impact this sub-region as much as other sub-regions. By 2100, sea levels are projected to increase by approximately 14cm (range of 4.5 – 32.4cm), but may rise as much as 0.6m to 0.9m [21,44]. Rising sea levels are likely to impact the extensive aquaculture infrastructure in this region (finfish and shellfish), and producers will likely have to adjust the locations of some of their nearshore facilities. Commercial forestry, fisheries, and marine shipping sectors should take sea level rise projections (see North Vancouver Island Sea Level Rise maps) into consideration when planning future processing sites and harbor infrastructure. Commercial tourism facilities such as fishing lodges and marinas will also have to adjust their docks and other near-shore infrastructure to account for rising sea levels and increased storm surge events.
Sea surface temperatures will likely increase, and salinity will likely continue to decrease across the coastline and within this sub-region [55,82]. Average sea surface temperature is projected to increase on average by 1.8°C by the end of the century compared to 1961-1990 baseline [21,22]. Sea surface salinity will decline by ~1% to ~3% with by the end of the century 1961-1990 baseline as the ocean freshens with increased precipitation, terrestrial runoff, and melting glaciers [21,36]. Increasing sea surface temperatures will threaten fisheries productivity, especially for finfish which are sensitive to temperature, and lead to shifts in marine species distribution . Rising temperatures and changing species distributions and abundance is likely to affect marine based food security for local communities. The commercial fishing industry is likely to continue to experience declining catch, particularly for temperature sensitive species such as salmon ([92,96,111]; Appendix 2 Table 1), and the extensive finfish aquaculture in this sub-region may also be affected .
Changes in ocean properties are also expected for the North Vancouver Island region. Ocean acidification is projected to continue, and average projections suggest that that ocean pH will fall to ~7.95 pH -7.68 pH under the IPCC high emissions scenario (RCP 8.5) by 2100 .
Some specific impacts at the scale of the North Vancouver Island sub-region are related to sea level rise and extreme weather events. There are numerous cultural and historic sites that may be particularly sensitive to rising sea levels based on recent shoreline sensitivity analyses (see North Vancouver Island Regional Shoreline Sensitivity Map). In particular, lower elevation foreshore or nearshore areas throughout the area are more likely to experience flooding and erosion.