Coastal First Nations and non-First Nations communities depend on the ocean and nearshore environments for economic, social, and cultural values. The coastal economy of British Columbia is largely based on the recreational tourism (33%), transport (29%), and seafood (12%) sectors [91,103]. Climate change will affect the coastal communities of the MaPP region through increased air temperature, changing precipitation patterns, accelerated sea level rise and the increased incidence of extreme weather events, such as storm surge related flooding, increased rates of coastal erosion, freshwater contamination from seawater inundation, and a suite of ecological changes associated with other climate changes. These communities are at risk for land loss, damage to coastal infrastructure, and changes to resource availability, all of which will affect economic, social, and cultural historical values .
Climate change impacts are likely to continue to unevenly affect communities along the coast due to different exposures to those impacts. An added dynamic is that any climate related impact has a cumulative effect on non-climatic issues already affecting these communities, such as declining resource industries, economic or social restructuring, and ongoing land claims agreements in the case of First Nations communities. In general, rural and remote communities in BC tend to have a lower socio-economic index, which is indicative of economic hardship, education, health, and other risk factors. These trends are indicative of community vulnerability, and low rankings in those social indicators suggests low adaptive capacity to manage large stressors like climate change .
Especially for First Nations communities, access and availability of traditional foods has decreased as ecosystems have been exploited or converted to other uses, and the productivity of remaining intact ecosystems has been impacted by factors including pollution, management actions, or invasive species. An example of an observed impact of climate change on community food security is the changing timing of wild plant ripening and harvest [67,94].
Air temperature and precipitation
Increasing air temperatures mean that winter heating requirements are likely to continue to decrease across the province, while summer cooling requirements and costs will increase . In some cases, increasing summer temperatures may negatively impact communities through mortality linked to heat stress. Most homes along the BC coast lack air conditioning, and it is likely that increasing air temperatures, especially during extremely high temperature events, will lead to greater incidence of heat stroke and potential mortality . However, increasing air temperatures may attract more tourism for a longer summer season, which will have positive economic implications for coastal communities.
Sea level rise
Sea level rise will not affect areas along the BC coast equally due to differences in vertical land movement . Observed sea level rise is also affected by local and regional contributions, including melting glaciers and ice sheets, water volume changes due to temperature and salinity effects, and vertical land changes from glacial rebound, tectonic processes, and compaction (land sinking) . Most of the north coast of British Columbia is steep and rocky, and therefore is less likely to be impacted by sea level rise. Notable exceptions include the northeastern coast of Graham Island, Haida Gwaii, an area which is amongst Canada’s most sensitive coastlines to climate change .
Many remote coastal communities and First Nations’ heritage sites are vulnerable to enhanced erosion and storm-surge flooding associated with sea-level rise (See Regional Map: Archaeological sites sensitive to sea level rise). In addition, groundwater quality could decline due to saltwater intrusion as sea levels rise .
Sea surface temerature
Increasing ocean temperatures will impact coastal communities that are reliant on fisheries and other marine species for food security and economic activities. Many species that are currently important to coastal communities (First Nations and non-First Nations) are projected to shift northwards from their current species range (at rates of 10-18 km/decade) and also decline in relative abundance (up to ~40% declines, depending on the species and climate scenario) .
Ocean acidification will impact coastal communities that are directly dependent on calcareous organisms such as shellfish for food and income . Acidification will also affect fisheries through negative impacts on food web dynamics and lower trophic level organisms . Shellfish are likely to be affected across life stages, and this decline in economically important species (oysters, scallops, abalone, mussels) will affect the economies of coastal communities in the region. Decreased access to these traditional foods also has implications for human health and culture .
Winds, waves, and extreme weather
While the impacts from sea level rise combined with extreme events and storm surge are projected to be highly problematic for the region, especially in low-lying areas, little is known about the interactions of extreme weather events and climate impacts along the BC coast  and thus within the MaPP region. Regional models of sea level rise and seasonal climatic variability patterns would improve the ability of coastal managers to predict flood hazards and associated risk factors for the region and sub-regions.