Key climate change risks and opportunities in the Prairies stem from the dry and variable climate; projected temperature increases that are greater than elsewhere in southern Canada; sensitivity of water resources, ecosystems and resource economies to seasonal and inter-annual variations in climate; and especially large departures (e.g. drought) from normal conditions. Recent rapid economic growth (especially in Alberta), a population shift from rural to urban, and most of Canada’s agricultural landscape and irrigated land are also important factors influencing vulnerability in the Prairies. Through the assessment of vulnerability for the region, the following conclusions can be drawn:
- Projected climate change is outside the range of recent experience with natural variability.
Significant recent warming, evident in instrumental and proxy climate records, is consistent with projections from global climate models (GCMs). With the exception of a few scenarios for the 2020s, all models forecast climates that are outside the range of natural variability experienced and observed in the twentieth century. The authors’ assessment of the sensitivities and vulnerabilities of natural resources and human activities reveals that the most significant threat posed by climate change in the Prairies is the projected increase in climate variability and frequency of extreme events. Climatic extremes, and especially droughts, will limit the opportunities afforded by changing climate and present the greatest challenges for adaptation. Climate models are unable to simulate extreme events and the variability of hydroclimate with the same level of certainty as that for future trends and variability in temperature. The most costly climate events in Canadian history have been droughts on the Prairies. Flooding is another costly climate event, with associated health impacts that include waterborne disease outbreaks, stress and anxiety. The historic recurrence of social and economic impacts resulting from drought suggest that future droughts of extreme severity or long duration will be the element of climate change and variability most likely to exceed the coping and adaptive capacities of communities and industries in the Prairies.
- Most economies and activities are not presently adapted to the larger range of climate conditions projected.
Some adaptation of prairie communities and economies has occurred in response to climate conditions of the twentieth century. From this short perspective, climate and water seem rather consistent, and resource management practices and policies therefore reflect a perception of relatively abundant water supplies and ecological resources within a relatively stationary environment. Future water and ecosystem management will have to abandon the assumption of a stationary environment, given the longer perspective from climate models and paleoenvironmental data, and the projected shifts in climate variability, biodiversity, disturbance regimes and distribution of water resources and ecological services.
- The major climate change vulnerabilities relate to changes in water availability and ecosystem distributions.
One of the most certain projections about future hydroclimate is that extra water will be available in winter and spring, whereas summers will generally be drier as the result of earlier spring runoff and a longer, warmer summer season of water loss by evapotranspiration. The net result will very likely be less surface water and soil moisture, but also greater variation from season to season and year to year. Water scarcity in some years will be a constraint for all sectors and communities, and could ultimately limit the current rapid economic growth, including development related to oil sands and expanded irrigation.
Major ecosystem shifts are expected with climate warming and drying. Aquatic habitats will be stressed, affecting various fish species, and some waterfowl populations will decline substantially. Change in terrestrial ecosystems will be most visible near sharp ecological gradients, such as in the mountains, in island forests and along the margins of the northern and western coniferous forests. Non-native plants and animals will appear on the landscape. Some native species will decline or disappear entirely. Other species will increase in numbers or geographic distribution, given adequate connectivity. Changing ecosystems could make some vector-borne diseases, such as West Nile virus and hantavirus pulmonary syndrome, more common.
- There are both advantages and disadvantages to shorter, warmer winters.
Much of the projected increase in temperature and precipitation will occur in winter and spring. There are several advantages of such changes, including reduced energy demand for heating and decreased mortality from extreme cold. On the other hand, there are advantages of cold winters, related to winter recreation, transportation over lake ice and frozen ground, and especially the storage of water as ice and snow, which is presently the most abundant, reliable and predictable source of water.
- Planned adaptation is a component of adaptive management and sustainable economic development.
Increasing demands on natural resources, combined with a current paradigm of sustainable development, have led to policy and processes in all sectors that are relevant to planned adaptation to climate change. Relevant existing policy and management instruments include sustainable community initiatives, infrastructure renewal, environmental farm plans, watershed basin councils and principles of adaptive forest management and integrated water resource management. With rapid urbanization in Alberta and general depopulation of rural areas throughout the Prairies, strategies for sustainable urban growth and for sustaining rural economies need to include the evaluation of climate risks and opportunities relevant to different sectors of the population and regional economies. For example, rural economic development will be strongly influenced by the impacts of climate change on natural resources, especially water supplies.
- There is a moderate to high level of adaptive capacity in the Prairies, but it is unevenly distributed and must be mobilized to reduce vulnerability.
An evaluation of the conventional determinants of adaptive capacity (natural and human capital, infrastructure, technology, etc.) suggests that there is a relatively high level of such capacity on the Prairies. A history of adaptation to a variable and harsh climate has built substantial adaptive capacity in the agriculture sector, which can now rely on various precedents for adapting to threats to productivity. Policies and management practices have been adjusted to address, for example, soil degradation, trade barriers and changes in export markets and transportation subsidies. The history of prairie agriculture has been a continuous process of adaptation and drought-proofing through innovation and improvements in water, soil, crop and pasture management. More severe drought will test this accumulated adaptive capacity.
Moderate to high adaptive capacity in other sectors can be attributed to risk management strategies and adaptive management practices, although these mechanisms have generally not been tested with respect to climate change. Barriers to adaptation may include lack of financial capacity, lack of understanding of the implications of climate change among managers, and existing policies that may prevent the implementation of adaptation measures.
Adaptive capacity is uneven geographically and among segments of society by virtue of their demographic, health, regional, socioeconomic or cultural circumstances. Populations most vulnerable in the Prairies include the elderly, children, those with underlying health problems, those with lower socioeconomic status, the homeless, family farmers and Aboriginal peoples. The elderly, Aboriginal and immigrant populations are the fastest growing and also among the most vulnerable to health impacts. Economic vulnerability often precedes negative health outcomes associated with extreme weather.
The present uneven geographic distribution of people and resources, with population and wealth concentrated in Alberta, will likely be further amplified by changing climate. Economic and social stresses related to climate change could encourage further migration from rural to urban communities and to regions with the most resources. A population shift from rural areas to large urban centres undermines the viability of rural communities and may put additional social pressures on cities. Rural communities, especially isolated ones with limited economic diversity, are most at risk due to limited emergency response capacity and dependence on climate-sensitive economic sectors (agriculture, forestry). Rural Aboriginal communities will experience these same stresses, in addition to threats to a subsistence-based livelihood.
Formal and informal institutions interact to either sustain or undermine capacities to deal with global challenges such as climate change. Efforts to improve adaptive capacity must deal with the existing institutional factors. To the extent that governance institutions organize the relationships between the state and civil society, they are fundamental in developing adaptive capacity. Social capital can be used to mobilize resources in order to ensure the well-being of persons, groups and communities. Social capital may be particularly important in dealing with the uncertainties and instabilities that climate change creates, complementing and even substituting efforts by governments. The few available studies show that people with higher levels of social capital are, on average, more informed, more optimistic and more empowered when it comes to dealing with climate change and water quality issues.