How Our Climate is Changing

Earth’s climate is changing as a result of increased atmospheric greenhouse gas concentra­tions, and we are already experiencing the effects.

Adapting to the new (and changing) normal will be a challenge, but being aware of the impacts will allow individuals, communities and governments more broadly to take steps to reduce the consequences. Learn about the projected conditions and climate shifts to expect in BC below. You can make a personal effort to reduce your footprint and adapt with our Tool Kit of ideas.

Air Temperatures are Increasing

In BC, the greatest increases in air temperatures have occurred in the central and northern parts of the Province, as seen on the map on the left. Air temperatures in the Eastern and Southern Vancouver Island regions have been relatively stable in the past, but are expected to become warmer and possibly more variable into the future.

Summer heat waves like the record shattering ‘heat dome’ event that blanketed an extensive area of the Pacific Northwest for a week will become more frequent and intense, especially in lower elevations and valleys.

Equally important to extreme heat waves are relatively warmer winter night-time minimum tempera­tures. In coastal areas there will be fewer days that dip below freezing except at higher elevations, which will have implica­tions for our snowpack and river flows.

Precipitation Patterns are Changing

In the future it is projected that the cooler months will see more precipitation, but the summer will become drier. Already we are observing changes to precipitation as seen in the map, which shows an increase in average annual precipitation over the last 100+ years in BC, with the greatest increases being in the BC interior. The Georgia Depression has seen the greatest seasonal precipita­tion change with 23% increase during spring months. In winter, less precipitation will fall as snow due to warmer temperatures. This results in reduced snowpack in higher elevations and a loss of consistent melt waters that are so important to sustain streams through the dry season.

Increased precipitation in the fall and winter is likely to create more frequent high river flow and run-off events, particularly because less will fall as snow. This can cause overland flooding and erosion along rivers, which could threaten homes and other structures. Heavy winter rainfall also has the potential to destabilize slopes, which could trigger mass movement events like landslides, as well as lead to blockages of logs and other debris, causing rivers to overflow their banks. Higher flows will impact salmon habitats by lowering water clarity due to increased sediment inputs, scouring spawning gravel and threatening the stability of riparian vegetation that provide salmon shade, cooler waters and insect food sources. Stronger flows could potentially make migration much more difficult for Pacific salmon, and wash away salmon eggs from their redds (nests) in the gravel.

The Sea is Getting Higher, Warmer, and More Acidic

Sea Surface Temperature

Long-term trends show that the sea surface temperatures have been increasing globally and the same is true along the BC coast. The rate of increasing sea surface temperature varies significantly by region around British Columbia. The increases have been most pronounced for the southern/inner coastal region where sea surface temperatures have been rising at a rate of 0.40°C per decade, whereas the temperatures in the northern/outer coastal region have been rising at 0.12°C per decade. If these trends continue, the sea surface temperatures in the Strait of Georgia may increase by 3°C by 2100.

Trend in annual sea surface temperature based on the observations of all lighthouses from the
British Columbia Lightstation Network Dataset. representing inner and outer coast stations. The bars represent anomalies, averaged across all monitoring locations, from the long-term average temperature (1935-2020). Blue bars indicate below average temperatures for that year and red above average. Error bars indicate the variability between lighthouse data for each year. Figure, used with permission, appears in the State of Pacific Ocean Report (DFO).

Warmer sea surface temperatures from climate change on top of natural climate fluctuations increase the risk of events known as marine heat waves. During marine heatwaves, the thermal tolerances of marine species can be exceeded and result in stress or death. In the future, these are projected to increase in frequency, intensity, duration and spatial extent globally.

Warmer waters have been implicated in the loss of important habitats such as eelgrass meadows and kelp forests which are crucial to the life cycles of many species including salmon.  Harmful algal blooms, biotoxins and disease outbreaks are also associated with warmer sea surface temperatures.

Ocean Acidification

As part of the normal carbon cycle, ocean waters absorb a portion of CO2 from the atmosphere and this influences the pH of the water. With higher levels of CO2 in the atmosphere seawater is becoming more acidic. More acidic conditions make it more difficult for organisms that rely on calcium carbonate for their shells to form properly. This will challenge shellfish growers and many of our native shellfish species, including clams and crabs. Larval crab and other small crustaceans are vital to the food web and are an important food source for juvenile salmon!

Sea Level Rise

Sea level rise also varies by region due to a number of factors. In BC, sea level rise is projected to be greatest on the north coast, the Fraser Lowland and around southern Vancouver Island, ranging from 50 to 70cm by the year 2100 (median model change under RCP8.5; not accounting for the possibility of Greenland and Antarctic ice sheet disintegration). The rest of Vancouver Island is projected to experience a much smaller relative rise in sea level - mainly due to tectonic uplift. Generally sea levels have been rising at an accelerating rate as the oceans warm and ice sheet melt. Even at the modest end of this range, our coastlines as we know them will inevitably change.

Maps depicting coastal areas shoreline sensitivity to sea level rise and flood risk along the Strait of Georgia. Degrees of sensitivity marked by red, amber, yellow, green and black in order from most to least sensitive. Areas that are projected to be vulnerable to coastal flooding by 2100 are shaded in blue. The 2100 coastal floodplain area dataset uses sea level rise and approximate flood construction levels (FCLs). It includes a nominal allowance for wave effects but does not account for river flooding effects nor a combination of these effects with sea level rise, the presence or absence of flood protection structures, and has not been ground truthed. Data are from the Province of BC and Kerr Wood Leidal.

With higher sea levels and larger and more intense winter storms coming together, many areas of our coast will be at risk. Low-lying regions will experience more frequent flooding. By 2050, historical extreme flood events that occurred once per century, are projected to occurring on average at least once a year in many low-lying regions. Crashing waves hitting higher on the shoreline will cause increased erosion. Coastal bluffs will crumble at greater frequency than they had previously. Shorelines that have hard armour, like rip rap and seawalls, may be undercut causing them to fail. In many locations, accelerated erosion and flooding may damage culturally important places, threaten structures and impact intertidal habitats.

Cascading Impacts

In sum, climate change will cause a myriad of challenges for British Columbians to adapt to. Depicted below are the projected changes expected for British Columbia and the cascading impacts that they will cause. Together these impacts may result in shifting ecosystems, where certain species may become locally extinct or conditions become more favourable for other species to become dominant; altered ways of life for communities such as relocation away from flood prone areas or redesigning homes and infrastructure to cope with extreme heat and storms; challenges for primary industries of forestry, agriculture, fisheries and aquaculture in light of the increases to wildfires, reduced water security during the growing season and warmer, more acidic seawater; and places of cultural significance may be lost or altered along with ways of life that have been practised in BC for millennia.

Additional Resources

Learn more about the impacts of climate change and ways that BC can adapt in this Climate Change Backgrounder video made by the Province of BC.

And check out University of Victoria's Pacific Institute for Climate Solutions page.

Explore the tools on the Changing Coastlines web platform, including a visualization of climate change impacts on varying sectors under different coastal flooding scenarios. You can also find a backgrounder on practical strategies that can help us implement the ‘protect, retreat, accommodate, avoid’ approaches to coastal adaptation.

References for the information contained within this post:

Amos, C.L., Martino, S., Sutherland, T.F., and Al Rashidi, T. 2015. Sea Surface Temperature Trends in the Coastal Zone of British Columbia, Canada. Journal of Coastal Research 300: 434–446.

British Columbia Ministry of Environment (MOE). 2016. Indicators of Climate Change for British Columbia: 2016 Update. Ministry of Environment, British Columbia, Canada.

Capital Regional District (CRD). 2017. Climate Projections for the Capital Region.

IPCC. 2019. IPCC Special Report on the Ocean and Cryosphere in a Changing Climate. eds. Pörtner, H.O., Roberts, D.C., Masson-Delmotte, V., Zhai, P., Tignor, M., Poloczanska, E., Mintenbeck, K., Alegría, A., Nicolai, M., Okem, A. Petzold, J., Rama, B., and Weyer, N.M.

NOAA. 2017. Global and Regional Sea Level Rise Scenarios for the United States. NOAA Technical report NOS CO-OPS 083.

Oppenheimer, M., Glavovic, B.C., Hinkel, J., van de Wal, R., Magnan, A.K., Abd-Elgawad, A., Cai, R.,
Cifuentes-Jara, M., DeConto, R.M., Ghosh, T., Hay, J., Isla, F., Marzeion, B., Meyssignac, B., and Sebesvari, Z. 2019.
Sea Level Rise and Implications for Low-Lying Islands, Coasts and Communities. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate. (Eds.) Pörtner, H.O., Roberts, D.C., Masson-Delmotte, V., Zhai, P., Tignor, M., Poloczanska, E., Mintenbeck, K., Alegría, A., Nicolai, M., Okem, A. Petzold, J., Rama, B., and Weyer, N.M.

Philip, S.Y., Kew, S.F., van Oldenborgh, G.J., Yang, W., Vecchi, G.A., Anslow, F.S., Li, S., Seneviratne, S.I., Luu, L.N., Arrighi, J., Singh, R., van Aalst, M., Hauser, M., Schumacher, D.L., Marghidan, C.P., Ebi, K.L., Bonnet, R., Vautard, R., Tradowsky, J., Coumou, D., Lehner, F., Wehner, M., Rodell, C., Stull, R., Howard, R., Gillett, N., and Otto, F.E.L. 2021. Rapid Attribution Analysis of the Extraordinary Heatwave on the Pacific Coast of the US and Canada June 2021. World Weather Attribution.

Photo credits: Jonathan Ford on Unsplash, Isobel Pearsall; Map Credit: Strait of Georgia Data Centre

Innovative Solutions for Biodiversity When Coastal Infrastructure is Necessary

Even in cities where there are long established wharves, ports and development on and over the water, there are ways to promote marine life and minimize impacts.

Explore the examples below to see how cities are considering nature in their coastal infrastructure.

Salmon-Friendly Overwater Structures

The City of Seattle is a great example. When repairs were needed for the downtown waterfront area, the city took this opportunity to try out some innovative solutions and rebuild the area with migrating Pacific salmon in mind. The newly designed pier and seawall beneath it are part of a larger project at Seattle’s Waterfront Park. This project aims to create open space for engaging and educational events, plus coastal habitat that supports marine life in the urban location.

Seattle's salmon friendly seawalls. Photo credit: Bob Oxborrow.

Rather than seawalls that plunge into deep water and are covered by solid walkways and structures, which create dark areas lacking habitat complexity, food resources and refugia that young salmon need (learn about these in this post about coastal modification impacts on salmon), the restored areas have a number of modifications so as to retain shallow and complex intertidal zones that receive sunlight.

The schematic below, from Waterfront Seattle, shows how the seawalls under the walkways and piers have been rebuilt.

Starting at the top, walkways were outfitted with light penetrating surfaces (1,2), including grating and glass blocks, to light up the areas below.

Instead of a flat featureless seawall, textured panels and habitat shelves were added to increase surface complexity (3,4). The texture promotes settlement of algae and invertebrates that, in turn, attract small fish. In the build, they have experimented with different types of texture, emulating cobbles in some areas and striated rocks in others.

Towards the low tide mark, so called ‘marine mattresses’, were installed (5). These added structures create shallow habitat that provide small critters and young salmon refuge from larger predators.

Researchers from the University of Washington’s Wetland Ecosystem Team, who provided input, are monitoring the project’s success. They are seeing that the steps taken are increasing biodiversity and improving habitat value. As hoped, salmon are using these areas more than they were under the traditional structures (see article). 

Above it all, in the popular public area, signs about the work provide an excellent learning opportunity for visitors to engage with. A number of articles published in news sites also helps create a buzz of interest in the work to a wider audience (see Hakai Magazine and NPR podcast).

See the students in UW School of Aquatic and Fisheries Sciences present in this work in a seminar hosted by Sound Water Stewards.

Examples of other initiatives around the world

Seattle is not alone, a number of other cities around the world are rethinking their water fonts. The World Harbour Project, headquartered in Sydney, Australia, has engaged a number of major international harbours, including four in North America, with the primary aim to promote research and restoration of ecosystem function in highly urbanized areas.

Examples of initiatives include:

Closer to Home
False Creek Flood Plain

Vancouver is reconsidering its waterfront areas as well. The recent storms that battered Vancouver – causing flooding and erosion – served as a shocking preview of what is to come with sea level rise. It is clear that innovative planning will be needed. Will nature be included in the new designs? Learn about the Sea2City Design Challenge, which aims to establish a plan for urban development and ecological revitalization for the False Creek floodplain of downtown Vancouver.

Native Oysters in Victoria’s Gorge Waterway

The only oyster species native to BC, the Olympia oyster, is struggling across its range due to historical exploitation and a number of stressors that prevent them from recovering. As a result of this, the Olympia oyster has been listed as a species of special concern. As important ecosystem engineers, meaning they perform important functions for the environment like building habitat (reefs), supporting biodiversity and improving water quality, encouraging oyster recovery should be a priority.

When the Craigflower Bridge, in the Gorge Waterway of Victoria, was being rebuilt the native oysters were looked after. The Olympia oysters around the old bridge were salvaged – collected and moved to artificial reefs – so as not to lose the creatures during the deconstruction. On the new bridge, textured panels were added to the footings and oyster reefballs, which are made up of substrate that encourages oyster settlement, were also placed around the Gorge Waterway to encourage more Olympia oysters to establish. Coastal Collaborative Sciences, who is carrying out the program, hopes to relocate the oyster reef balls to other locations in hopes of re-establishing populations elsewhere.

Photo, provided by World Fisheries Trust, showing dense oysters colonized on a reefball in the Gorge Waterway.

Salmon and Shoreline Modifications

Coastal and estuarine areas, which are often extensively modified in urban centres with shoreline hardening and structures such as docks and piers, are vital stop-over habitats where young salmon grow, adjust and prepare for their life at sea.

Features such as seawalls, riprap, docks, and piers, alter how shorelines function and they also affect Pacific salmon during their coastal phase of life. How well salmon grow during their time in coastal areas is directly linked to their success out at sea, and ultimately, whether they make it back to spawn the next generation.

Salmon utilize complex and diverse shoreline habitats as they grow in the coastal environment. They are supported by habitats such as eelgrass meadows, kelp forests and shallow beaches for refuge and abundant food sources. Overhanging riparian vegetation moderates beach temperatures for spawning forage fish and provides terrestrial food inputs.

When Pacific salmon first migrate down to coastal habitats, they preferentially use shallow areas and shift along the depth gradient and between habitats as they grow. Shoreline modifications, like seawalls that extend into the lower subtidal zone, eliminate shallow areas and complex habitat gradients. Shallow habitats are particularly important for the smallest salmon as they offer refuge from larger predators that cannot access those areas. Without the shallow areas, young salmon must occupy the same areas as larger fish, leaving them more vulnerable to predation.

On armoured shorelines, salmon are unable to access their preferred prey items. Studies have found that shoreline armouring reduced the number and diversity of epibenthic invertebrate (critters that reside on or above the rock, sand and mud of the seafloor) and the availability of terrestrial insects compared to unarmoured areas. As a result, when young salmon are next to a seawall and other artificial structures, they end up feeding on alternative prey types such as planktonic prey that might be harder to catch and less nutritious.

Quality shallow habitat is also lost under traditional overwater structures, such as piers and docks. The areas beneath them are bleak. The structures cast too much shade so seagrasses and algae can not thrive below. While you may be able to spot crabs and some barnacles or mussels under these structures, overall, there are few fish or other animals. Salmon also avoid these areas – it is too dark – and the lack of light seems to make salmon nervous. They also cannot see their predators, find ample prey, properly orient themselves, or school together. They end up altering their natural behaviours and avoid the shallow areas that should be their safe

Coastal modification also disrupts overall land and sea connectivity. Coastal riparian vegetation is lost on modified shores along with the insects that would fall into the water – and these terrestrial insects are another important food source for salmon. Surf smelt, a prized prey item for salmon as they grow in coastal areas, also suffer without overhanging coastal vegetation. The shade of the vegetation regulates the temperature of the upper shoreline and this is important for successful surf smelt beach spawning.

Watch this video by expert Dr. Stuart Munch from NOAA to learn more about the impacts of shoreline modifications on salmon and solutions to mitigate them in Puget Sound. Video provided courtesy of Raincoast Conservation Foundation.

Credits: Illustration by Holly Sullivan; Salmon in city photo by Tavish Campbell on Flickr

What are Nature-based Solutions

Nature-based solutions harness nature’s resiliency to tackle pressing environmental and societal challenges in a sustainable, mutually beneficial way.

Nature-based solutions include both protecting natural ecosystems and enhancing developed landscapes to improve well-being through the ecosystem services that natural (or semi-natural) ecosystems can provide. Since nature-based solutions work with nature rather than against it, they are typically more affordable and longer-lasting than their engineered counterparts.

Ecosystem services - any positive benefit that wildlife or ecosystems provide to people. This includes provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services such as nutrient cycling that maintain the conditions for life on Earth.

Millennium Assessment/

The following is a short video by the Nature-Based Solutions Initiative that introduces the concepts of nature-based solutions and the benefits they can provide.

Examples of How Nature can be a Solution

Natural shorelines, a solution for sea-level rise:

Restoring and protecting natural shorelines is an important nature-based solution to address sea-level rise. With much of British Columbia’s population concentrated along the coast, we have a lot to lose as sea levels rise.  When kept natural, rather than hardened with seawalls or other coastal modifications, shorelines will buffer wave energy and, through natural coastal processes, will dynamically adapt to rising sea levels, keeping the upland areas protected. Additionally, natural shorelines provide habitats for productive coastal ecosystems that Pacific salmon rely upon.

A more natural shoreline provides habitat for salmon and many other critters. It dynamically accretes sediment and buffers wave energy. Meanwhile, a man-made seawall is static, providing little habitat to support biodiversity, and energy from waves is deflected resulting in erosion and can cause overtopping.
Trees, a solution to keep us cool (and so many other things):

Trees provide many ecosystem services, and the planting and protection of forests and trees in our communities are an important nature-based solution to climate change. Firstly, trees remove and store carbon from the atmosphere, helping to offset emissions and slow climate change. They also act as a sponge soaking up water when it rains and storing it for when it is dry, thereby reducing runoff, flooding, erosion, and helping maintain aquifers. Shade from trees moderates temperatures, keeping forests, towns and waterways cool in summer and less exposed in winter.

When trees are planted in agricultural fields, livestock receive similar benefits. In cities, planting trees and maintaining forested green spaces reduces the heat island effect – keeping us cooler. Trees provide habitat and food for all kinds of animals, including economically important pollinators. Along streams and shorelines, trees stabilize the riparian zones and keep the waters cool, clean and clear, which is vital for Pacific salmon.

Wetlands, a solution for clean water:

Wetlands, which can also store tremendous amounts of carbon, act as water reservoirs, support biodiversity, and naturally purify water. In fact, wetlands are so effective at cleaning water that many places around the world rely on wetlands to treat wastewater (industrial and domestic) instead of traditional engineered (e.g. expensive) treatment plants. The soils, plants, and microorganisms in wetlands can break down harmful chemicals, take up nutrients, and filter particles. In urban landscapes, there are considerable areas that are impermeable – such as roofs and paving – and when it rains, water runs off these surfaces, picking up residues and pollution as it flows. Directing this stormwater runoff to human-created urban wetlands and rain gardens is an efficient nature-based solution to remove these pollutants from stormwater runoff, while also increasing infiltration to the local groundwater resources and mitigating flooding. A rain garden built on a small scale is something that can even be done on an individual’s property (learn more about how to build one here).

Find more nature-based solutions that you can implement and other ideas to reduce your environmental impact in our Tool Kit.

Learn About Nature-based Solutions in Action Around Canada and B.C.:

How Canada could offset 11 percent of its emissions through nature-based solutions by 2030

The potential for blue-carbon solutions (carbon sequestration in the coastal ecosystems: restoring marshes and opportunities with kelp) in Canada

How living dikes can be a solution for rising sea levels in B.C.’s Fraser delta

Learn More About Nature-based Solutions:

Nature-based Solutions Initiative – University of Oxford

IUCN Nature-based Solutions – International Union for Conservation of Nature

What are nature-based solutions and why do they matter? – Climate Home News

Nature and Climate, Impacts and Solutions – World Wide Fund for Nature

What are nature-based solutions? – David Suzuki Foundation

Seven lessons for planning nature-based solutions in cities based on 15 case studies across Europe. Environmental Science & Policy

The Role of Coastal Engineering and Geomorphology in Designing Resilient Coastlines

The Role of Coastal Engineering and Coastal Geomorphology in Designing Resilient Coastlines

Coastlines are shaped by the combined effects of water, winds, sediment, vegetation, and wildlife, and now – more than ever - human alterations. Coastal engineering and coastal geomorphology focus on understanding these processes and designing to accommodate them. Traditionally when engineers were designing shoreline projects, there was a tendency to want the shoreline to stay very static, despite the fact that it exists in the midst of a very dynamic environment. In the Pacific Northwest, there are many shorelines upon which seawalls and rock revetements were built that have caused significant shoreline degradation.

The implementation of successful nature-based projects such as Green Shores® for Homes and Green Shores for Shoreline Development Green Shores Home - Stewardship Centre for BC ( requires careful consideration of all the forces that shape the shoreline. It is also important for project designs to protect the upland, riparian and foreshore while meeting the needs of the landowner for values such as aesthetics and structure safety. Today coastal engineering works as part of a multi-disciplinary team of biologists, landscape architects and other environmental specialists to consider the local conditions at the site, and how best to provide adaptation to dynamic factors such as climate change.

In this video presentation you will meet two practicing Coastal Engineers who will share their insight of how they became interested in this profession, and how they enjoy applying their skill sets and knowledge to the increasingly complex world of shoreline protection.

Biographies of video speakers:  Grant Lamont and Jessica Wilson

Grant Lamont, Masters of Applied Science (M.A. Sc.), Professional Engineer (P. Eng.), is a Principal and Coastal Discipline Lead for Northwest Hydraulics Consultants (NHC) in Vancouver. His experience includes concept design, construction supervision, managing field data collections, and the application of physical model studies for detailed design. His experience with physical modelling includes ship motion studies, breakwater stability investigations, and sediment transport modelling as both a consultant and while working at the National Research Council (NRC) laboratory in Ottawa. As a senior Principal at NHC, Grant has helped assembled a team of professionals that is committed to improving shoreline design through the application of a multidisciplinary approach that considers physical processes as well as ecology and anthropogenic impacts. Grant is also Green Shores® Approved Professional Approved Professionals - Stewardship Centre for BC having completed Green Shores Level 3 and is co-chair of the Green Shores® technical committee.

Jessica Wilson, M.A.Sc., P.Eng, is an experienced Coastal Engineer, located in NHC’s Nanaimo Office. She has been involved in every stage of the coastal engineering process, from site reconnaissance and conceptual design through to construction supervision and project management. Jessica also has extensive experience using both qualitative conceptual models and more sophisticated numerical models for defining coastal processes (such as current, wave, and sediment transport). Much of her work focuses on the use of nature-based techniques to adapt to sea level rise and she has completed Green Shores Level 2 training. As a graduate researcher, Jessica’s work focused on assessing and developing design guidance for nature-based coastal protection using anchored large woody debris (LWD). She was also a visiting researcher at the Technical University of Delft, Netherlands, helping to study the use of vegetation for wave damping and sea level rise adaptation.