Our climate is changing and the impacts are already being felt across Canada. This section provides a brief overview of the current and projected climate change impacts that threaten the well-being of Canadians and a synopsis of threats and opportunities resulting from climate change. For the purposes of this report, we have synthesized these impacts into seven categories that have special relevance for social policy:
- Increased severity and frequency of heat events
- Severe storms, including extreme wind, rain, ice, and/or snowfall
- Water shortages and drought
- Changes in the cryosphere – melting permafrost, sea ice, lake ice, and snow
- Shifting ranges and altered ecosystems, including disease, pest and invasive species migration
- Sea level rise, storm surges, coastal and shoreline erosion
The Fourth Assessment Report of the Intergovernmental Panel on Climate Change, issued in 2007, presents a thorough analysis of climate change based on the assessment of the world's leading climate scientists. Working Group I, whose analysis focused on physical scientific evidence, reports that global atmospheric concentration of carbon dioxide had increased to 379 parts per million (ppm) in 2005, higher than any value previously recorded (IPCC, 2007). By 2008, that value had risen to 385 ppm.
Current projections, as summarized in the Third Assessment Report of the Intergovernmental Panel on Climate Change, suggest that global average temperature could rise by 1.4°C to 5.8°C between 1990 and 2100 (Foland, Karl, Christy et al., 2001). Due to our northern latitude and large land mass, Canada is projected to experience greater rates of warming than many other regions of the world – by some estimates, more than double the global average (Lemmen and Warren, 2004).
Reductions in emissions, while crucial in reducing the likelihood of the planet becoming completely uninhabitable, will not alter many of the climate changes that have already been set in motion by CO2 concentrations that already exist and will continue to increase even as we slow down our fossil fuel consumption (IPCC, 2007).
The greatest warming in Canada, on an annual basis, will occur in our Arctic regions. A mid-range estimate shows a possibility of global mean warming of 2.8°C by 2090-2099. Winter warming in Canada is projected to be 7°C or more in the high Arctic, 3°C to 4°C in Ontario and southern Quebec, and about 2.5°C along the B.C. coast. In the summer, the most warming is expected to occur over southern interior B.C. and the southwestern Prairies, up to 4°C. A summer warming of between 2.5°C and 3.5°C is expected over most of the rest of Canada, with the exception of the Arctic coast (1°C). This trend is a continuation of the observed warming, as summarized in Canada's National Assessment (Warren and Egginton, 2008).
Projected and current impacts of climate change include droughts, surface and ground water quality and supply issues, increases in the range of vector-borne disease, more frequent heat waves with high discomfort in urban centres, and exacerbated ocean storm surges. Resource-based communities will be vulnerable to economic and other difficulties caused by shifting ecosystems, and increasing weather extremes such as intense precipitation caused by shifts in the hydrological regime, high winds, or ice storms are among the greatest concerns for Canada's social structures and communities (Lemmen and Warren, 2004; Berry, McBean and Séguin, 2008). Heavy precipitation events are likely to become more frequent, with larger variations in intensity (Walther, Post, Convey et al., 2001), and seasonal changes expected to be more significant than changes in annual totals in terms of impact on human activities and ecosystems (Lemmen and Warren, 2004).
Increases in the frequency of extreme weather events, such as heat waves, droughts, floods, and storms, are one of the greatest concerns. As well, higher temperatures are projected to increase damage from disturbances such as forest fires and pests, and increase heat-related morbidity and mortality (Lemmen and Warren, 2004). In the North, changes in ice cover, permafrost stability and wildlife distribution are already hindering traditional ways of life (Berkes and Jolly, 2001). In other regions of Canada, changes in water flows, fish populations, tree distribution, forest fires, drought, and agricultural and forestry pests have all been associated with recent warming (Lemmen and Warren, 2004). In the past decade, losses from the 1998 ice storm, flooding in Manitoba and Quebec, drought and forest fires in western Canada, storm surges in Atlantic Canada, and numerous other events clearly demonstrate our vulnerability to climate extremes (Lemmen and Warren, 2004). The profound changes that are occurring or will occur as a result of the current and projected impacts of climate change are threatening, and will continue to threaten, the well-being of Canadians.
The main response to climate change so far has focused on mitigation through the reduction of greenhouse gas (GHG) emissions. Such a response is undoubtedly crucial to lessen the likelihood of the planet becoming uninhabitable, but it is far from adequate; damage caused by current and future emissions is already occurring and will continue to increase. Current CO2 concentrations in the atmosphere are extensive enough to mean that our climate will continue to change regardless of our success at curtailing emissions and slowing down our fossil fuel consumption (IPCC, 2007). Therefore, our response to climate change must involve adaptation, or adjustments made to cope with or take advantage of the changing climate. The distinction between mitigation and adaptation is particularly apt in the area of social policy; while mitigation is vital to reducing the extent of future climate change, adaptation is essential to help reduce vulnerability of human systems in the face of current and expected climate-related impacts.
Continued climate change as projected by current climate models will impact all areas of the country and nearly every sector of the Canadian economy. Recent research indicates that no sector will be immune, whether it is directly affected by changing climate conditions or by mitigation measures taken to reduce greenhouse gas emissions (International Labour Organization (ILO), 2008). Primary sectors, such as agriculture, forestry and fisheries, may be the most severely affected, while changes in vacation destinations will impact the tourism industry, either negatively or positively, depending on the region (ILO, 2008).
Besides risks, climate change may also provide benefits, such as an extended growing season or warmer winter temperatures. While it is prudent – and necessary – to acknowledge Canada's vulnerabilities to climate change, we also recognize the opportunities for Canada that may arise out of a changing climate. There is potential for adaptation planning and mitigation mechanisms to stimulate Canada's economy by taking advantage of emerging markets for new technologies and energy sources while also tapping into Canada's immense natural capital.
Furthermore, the expansion of non-farming and non-extractive activities in both the forestry and agricultural sectors could lead to new technologies and job growth. Depending on inputs, changing climate conditions could positively impact the agricultural sector, and growing conditions may improve in some regions or for some crops; however, the ability to expand agriculture will be constrained by soil suitability and water availability (International Labour Organization, 2008). Investments in adaptation could lead to employment and income opportunities through extending coastal defences, reinforcing buildings and infrastructure and water management; and green collar jobs could mitigate job losses associated with a transition to cleaner energy sources (International Labour Organization, 2008). Employment may also expand in the health sector as health needs rise from the increased risk of diseases and emergency management (International Labour Organization, 2008).