Impacts of Climate Change
Extreme Weather Events: Floods, Fires, and Droughts
As climate change continues to worsen, extreme weather events across BC are increasing in both frequency and intensity. Higher temperatures are contributing to an unprecedented increase in droughts and forest fires as well as more frequent storms and other unusual weather events, which are leading to intense flooding, often caused by torrential rain.22 These different climate disruptions often exacerbate one another – droughts, for instance, may leave soil with a lower water absorption capacity in situations of intense rainfall resulting in flooding.
In recent years, forest fires have been particularly destructive in BC. The 2017 and 2018 wildfires in BC had devastating impacts on both human health and the environment leading to increases in respiratory and mental health problems, damage to property, and population displacement. Although fires were mild in 2019, 2020, and 2022 due to increased precipitation in the early summer months, the BC Wildfire Service declared several fires to be highly notable.23,24 The fire season of 2021, however, was one of the worst on record – particularly exacerbated by the heat dome which brought record high temperatures to much of the province. The 2021 fires not only destroyed large swaths of forests, but also the town of Lytton, which was evacuated before much of the town’s infrastructure was burned.
In response to worsening forest fire seasons, the BC government has taken measures to reduce unnecessary fire activities, especially in smoke sensitive zones (Figure 2), as smoke can directly exacerbate respiratory illnesses, such as COVID-19.25 If anthropogenic emissions increase, it is likely that the frequency and severity of future forest fires in BC will also accelerate. The resulting increase in smoke and heat will continue to have unprecedented negative impacts on human health.24
Thea de Paoli shares her experience with wildfire evacuation in Kimberley, BC (0:49)
Dr. Alan Ruddiman shares his experiences of the 2003 Okanagan wildfire and how this represented a turning point for his climate advocacy work (1:01)
George Abbott discusses BC’s preparedness for wildfires and floods (3:35)
Loss of Species
As the effects of climate change worsen, plants, animals, and insects across BC are coming under threat. Climate change is inducing both habitat expansion, for some species, and contraction for others. This phenomenon is driving habitat loss, displacement, and the inception of undesirable and often harmful species interactions.26
The mountain pine beetle, for example, has been expanding its range into areas that were previously uninhabitable due to temperature limitations such as Eastern and Northern Canada.27 As pine beetle populations increase, the natural defences of trees become overwhelmed. The insects are infecting and causing significant damage to populations of lodgepole and Jack pine trees.28
As temperatures continue to rise at the current rate, it is predicted that destructive patterns, such as that of the mountain pine beetle, will increase in the coming years affecting countless other species including salmon, which are a cultural food staple for many Indigenous communities (Figure 3). The Sahtu in Northern BC, for instance, depend on hunting and fishing practices to sustain their local economy, culture, and traditions.29 As populations of key species decline, so too will the ways of life and well-being of rural communities which rely on the health and survival of their surrounding ecosystems.
Case Study: Warming Climate Shrinks BC Beetles
The impacts of climate change are a growing concern among scientists and environmentalists around the world. An important area of research has been on the impact of climate change on animal species and their survival. One such study led by Michelle Tseng, an evolutionary ecologist at the University of British Columbia. Her team sought to determine how global warming affects the size of beetles, an essential component of Canadian agricultural ecosystems.30
Beetles are one of the most diverse and abundant insect species on the planet and account for a large proportion of insect biomass.31 Beetles play a vital role in agricultural ecosystems, serving as prominent decomposers and predators that reduce populations of invertebrate pests such as aphids and caterpillars.31 However, climate change is driving up temperatures, resulting in significant changes in beetle physiology and habitat.
Assisted by curators at the Beaty Biodiversity Museum, Tseng and undergraduate students researchers looked at eight species of beetles from the Lower Mainland and the Okanagan present over the past 100 years.32 From establishing a database of 6,500 beetles, they were able to compare information on each insect, when it was collected, and where it was found.32 After measuring whether beetles had changed in size, students used a climate database from the University of British Columbia’s Faculty of Forestry to collect information on environmental changes in the study regions. They found an increase in autumn temperatures of 1.6°C in the Lower Mainland and 2.25°C in the Okanagan over the last 45 years.32
The study revealed that the larger beetle species were shrinking while the smaller beetle species were not. They proposed that the mechanism involved is the rise in the metabolic rate associated with higher temperatures. Beetles enter life stages and reach adulthood more quickly, without gaining the typical amount of body mass.33 This is evidence that beetles in BC are responding to changing environmental conditions as a result of global climate change.
While it is clear that these organisms are adapting, this study highlights how much of an impact climate change has even on the smallest of species which can cause significant impacts on the ecosystem. Small beetles, for instance, can have more difficulty finding mates and competing for resources, which could lead to a decrease in the population size. It is therefore urgent to address the issue of climate change and its implications for different species in order to protect ecosystems and their vital functions.
Sea Level Rise
As climate change progresses and its effects, such as rising temperatures, worsen, sea level rise is becoming an increasing issue. Increased sea ice and glacier melt is considered a leading cause for rising sea levels in BC coastal communities. Winter sea ice areas are decreasing by 8% per decade in eastern Canada and glaciers and ice caps are projected to lose 74% to 94% of their volume later in this century.34 These numbers are a cause for deep concern as the melting of sea ice and glaciers poses significant risks to both environmental and human health. It is predicted that by the summer of 2050, most Canadian Arctic marine regions will be sea ice-free and, by 2100, most small ice caps and shelves will melt away.34 It is predicted that sea ice will continue to melt across the Canadian Arctic throughout the summer period, exacerbating sea level rise and resulting in habitat loss for species that depend on sea ice.34
Sila Rogan shares the impact of climate change on the sea ice patterns in her northern hometown (2:00)
BC’s coastal region is home to a large proportion of the province’s population making sea level rise and its consequences a significant climate risk as sea ice and glacier melt accelerates in northern Canada. A BC Ministry of Environment risk event scenario analysis shows a projected 25% decline in glacier area within BC by 2050, relative to 2005, showing how quickly the situation is progressing.35 Rural communities in coastal BC are more vulnerable to sea level changes, particularly when resulting in flooding, as many people rely on the sea for their livelihoods. The fishing industry, for instance, relies heavily on stable coastal conditions in order to fish, process and export their goods.36 The 2014 dam breach in Quesnel Lake, for example, significantly and negatively impacted drinking water sources and salmon spawning ground.
Coastal conditions are now far from stable with average sea levels rising at a rate of 13.3 centimetres per century around Prince Rupert, 6.6 centimetres per century around Victoria and 3.7 centimetres per century around Vancouver (Figure 4).35 Communities in and around these areas will face more frequent and severe flooding in the coming years causing concern for human health as well as impacts on socioeconomic factors such as housing and food insecurity if immediate action is not taken to build flood-resistant infrastructure and mitigate sea level rise.37
