Executive Summary

Records indicate that air temperatures in British Columbia have increased ~1.3⁰C since 1900. Climate projections from the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (2014) point to much greater warming for the remainder of the century. These models project increases in annual air temperatures in British Columbia (BC) of, on average, 1.8⁰C by the 2050s, and 2.7⁰C by the 2080s (PCIC). Projected changes in annual precipitation for BC are less significant, but overall more precipitation is likely, with warmer wetter winters and drier summers. Sea surface temperatures in BC are projected to increase by 0.5-2⁰C by 2065-2078, and ocean pH is predicted to continue to decline. Sea levels are projected to increase by 80cm to 120cm by 2100, with variability expected across the region. Dissolved oxygen levels and sea surface salinity in BC will likely decline overall. Increases in extreme weather events and spring runoff, and declining winter snowpack, are likely in BC, with projections consistent across different climate models.

These projected changes are relevant at the scale of the MaPP region. Where data exist, we comment on the nuances of these changes at the MaPP regional and sub-regional scales. With these projected changes, some sectoral impacts to consider for the MaPP region and the wider BC coast include: 

Ecosystems 

• Warming waters and increasing rates of ocean acidification are affecting and will likely continue to affect marine ecosystems and species. 
• Rising sea levels and increasingly intense waves, winds, and storms will affect coastline habitats and species composition.

Fisheries and aquaculture

• The geographical ranges and species composition of marine ecosystems are changing. This is linked to warming ocean temperatures and changing marine habitats.
• Rising stream temperatures will likely negatively affect freshwater fish including the freshwater life history of salmon species. Changing timing of snowmelt, further exacerbated by decreased summer precipitation, may make this impact worse. 

Human communities

• Coastal erosion and sea inundation from storm surge, especially in northern areas, will likely increase. These impacts are linked to sea level rise, increased storminess and wave events, and increased precipitation combined with the effects of warming trends on timing of snowmelt, given the contribution of spring snowmelt to floods within the province of BC.
• Increasing air temperatures and changing seasonality may provide opportunities to the tourism sector and economies of coastal communities by lengthening the summer tourist season, but could also provide potential problems to local populations who are adapted to current seasonal timing.
• Changing fish species composition will affect the fishing sector, coastal communities and economies. 

Marine Infrastructure

• Coastal infrastructure is likely to be affected by increasing extreme weather events, rising sea levels, and increased risk of flooding affecting shore-based infrastructure and buildings. 
• Transportation corridors for marine shipping will be affected by increasing winds, waves, and storms. Ports and harbours would do well to plan proactively for increased wave heights and storm surge events. 

Proactive planning for adaptation based on these climate projections and associated risks for key species would decrease the likely impacts on the sectors outlined above.  However, there are critical gaps in knowledge for many climate change projections and impacts, especially in the marine environment and at fine spatial scales. Improved climate projections and sub-regional vulnerability and risk assessments would improve integrated coastal decision making and planning supporting healthy coastal communities and economies.