Risks and Opportunities: Socioeconomic Sectors

4.1 AGRICULTURE

“Agriculture is both extremely important to the Canadian economy and inherently sensitive to climate.” (Lemmen and Warren, 2004, p. xi)
“Agricultural production, more so than any other form of production, is impacted the most by the weather.” Stroh Consulting, 2005)

Biophysical Impacts and Adaptation

Agriculture in the Prairies could benefit from several aspects of the warming climate, depending on the rate and amount of climate change and ability to adapt (Table 9). Benefits could result from warmer and longer growing seasons and a warmer winter. Increasing temperature will be positive for crop growth and yield, up to certain thresholds. As agricultural producers are highly adaptive, they should be able to take advantage of these positive changes. Negative impacts may result from changes in the timing of precipitation, increased risk of droughts and associated pests, and excessive moisture (Table 9). Newly emerging threats and opportunities, such as the increased probability of drought in areas where frost or excess moisture are currently greater threats, will be more challenging to adapt to, as people in those areas have had less experience in dealing with drought.

TABLE 9: Future possible changes in agri-climates for the agricultural region of the Prairies, and examples of possible advantages and disadvanages for agriculture.

Index	Changes (relative to 1961-1990 unless noted)	Climate model and emission scenario	Period and spatial pattern	Reference	Possible advantages for agriculture1	Possible disadvantages for agriculture1
Thermal indices:
Growing degree - days	25 to 40%	CSIROMk2b B2, greater changes with the other models	2050s; greater changes in the north	Thorpe et al. (2004)	More crop options; more crops per year; improved crop quality; shifts to earlier spring and later fall growth	Accelerated maturation rates andlower yields; increased insect activity; changed herbicide and pesticideefficacy
	42 to 45%	CGCM1 GA1	2050s for Lethbridge and Yorkton	CCIS2 (2002)
Heating degree-days	-23%	CGCM1 GA1	2050s for Lethbridge and Yorkton	CCIS2 (2002)	Decreased heating costs
Cooling degree-days	146 to 218%	CGCM1 GA1	2050s for Lethbridge and Yorkton	CCIS2 (2002)		Increased ventilation for barns, more cooling shelters and air conditioning
Hot spells: 20-year return period of maximum temperature	1 to 2°C increase	CGCM2 A2	2050	Kharin and Zwiers (2005)		Heat stress to plants and animals; increased transpiration rates can reduce yields; increased need for water for cooling and drinking
Cold spells: 20-year return period of minimum temperature	2 to >4°C increase from 2000	CGCM2 A2	2050	Kharin and Zwiers (2005)	Decreased heat stress to animals	Increased pests and diseases; increased winterkill potential
Moisture indices:
Soil moisture capacity (fraction), annual	>0 to <–0.2; mostly drying	CGCM2 A2 ensemble mean	2050s; greatest decreases in south to southeast	Barrow et al.(2004)		Increased moisture stress to crops; decreased water availability
Palmer Drought Severity Index	Severe droughts twice as frequent	Goddard Institute for Space Studies	Doubled CO2 for southern Saskatchewan	Williams et al. (1988)		Increased damages and losses from droughts; increased costs of adaptation, etc.
Moisture deficit: annual precipitation minus potential evapo-transpiration (P-PET)	–60 to –140 mm (i.e. increased deficit of 0 to –75mm	CGCM1 and HadCM3	2050s	Gameda et al. (2005)	As for droughts	As for droughts
		CGCM1 GA1	2050s	Nyirfa and Harron (2001)	As above	As above
Aridity Index (AI): ratio of annual precipitation and potential evapotranspiration (P/PET)	Area of AI <0.65 increases by 50%	CGCM2 B2	2050s	Sauchyn et al. (2005)	As above	As above
Number of dry days: time between 2 consecutive rain days (>1 mm)	Modest and insignificant changes	CGCM2 A2	2080 to 2100	Kharin and Zwiers (2000)
Number of rain days	Modest and insignificant changes	CGCM2 A2	2080 to 2100	Kharin and Zwiers (2000)
Precipitation extremes: 20-year return period of annual extremes	Increase of 5 to 10 mm and return period decreases by about a factor of 2	CGCM2 A2	2050	Kharin and Zwiers (2005)		More flooding and erosion concerns; more difficult planning for extremes
Snow cover	Widespread reductions	CGCM2 IS92a	Next 50 to 100 years	Brown (2006)	Decreased snow ploughing; increased grazing season	Decreased quantity and quality of water supplies
Other indices:
Wind speed, annual	<5 to >10%	CGCM2 A2 ensemble mean	2050s	Barrow et al. (2004)	Greater dispersion of air pollution	Greater soil erosion of exposed soils; damage to plants and animals
Wind erosion of soil	16%	Manabe and Stouffer	Doubled CO2	Williams and Wheaton (1998)
	-15%	Goddard Institute for Space Studies	Doubled CO2
Incident solar radiation	<–2 to <–6 W/m2	CGCM2 A2 ensemble mean	2050s; greatest decreases in central north	Barrow et al. (2004)	Decreased radiation may partially offset heat stress	Reduced plant growth if thresholds are exceeded
Climate Severity Index3	–3 to –9	CGCM1 IS92a	2050s; greatest improvements in Alberta and Manitoba	Barrow et al. (2004)		Less severe climates for outside work; more suitable for animals
Carbon dioxide	Various emission scenarios used (e.g., 1% per year)	IS92a		Leggett et al. (1992)	Increased plant productivity, depending on other limits	Possible reduced quality of yield
Notes: 1 Most of the advantages and disadvantages are summarized from Wheaton (2004) 2 Climate Change Impacts Scenarios (CCIS) project 3 Climate Severity Index (CSI) is an annual measure of the impact of climate on human comfort and well-being, and of the risk of certain climatic hazards to human health and life, with a scale ranging from 0 to 100 (Barrow et al., 2004); higher CSI indicates more severe climates; severity is weighted equally between winter and summer discomfort factors, and psychological, hazards and outdoor mobility factors

Climate change projections have been used to drive crop production models for many years (e.g. Williams et al., 1988). However, results of assessments are still wide ranging, depending on the climate scenarios and impact models used, the scale of application, the assumptions made (e.g. Wall et al., 2004) and how adaptation is incorporated. One of the most important climate change impacts relates to changes in the availability of water for agriculture. All types of agriculture depend upon a suitable amount, quality and timing of water. Agriculture is Canada's largest net consumer of water (71%; Harker et al., 2004; Marsalek et al., 2004; see Case Study 2). Agricultural water use has shown steady growth since 1972, and this trend is likely to continue (Coote and Gregorich, 2000). Irrigated agriculture and large-scale livestock production are constrained by water availability (Miller et al., 2000), especially in drought years (Wheaton et al., 2005a). For example, animals require more water during times of heat stress, and water stress during critical times for plants (e.g. flowering) is especially harmful. Alberta has about 60% of Canada's irrigated cropland (Harker et al., 2004) and, in 2001, the Prairies had more than 67% of the beef cattle, dairy cattle, hogs, poultry and other livestock in Canada (Beaulieu and B édard, 2003). Populations of both cattle and hogs have increased steadily in the past 10 years (Statistics Canada, 2005c). The demand for water for irrigation and livestock is expected to rise with increasing temperatures and expansion in these sectors.

Irrigation is the major agricultural adaptation to annual soil water deficits (see Case Study 2), and the move in recent decades to more efficient irrigation techniques has dramatically increased on-farm irrigation efficiencies. However, the continued loss of water from irrigation reservoirs and open-channel delivery systems due to evaporation, leakage and other factors indicate the need for further improvement in the management of limited water resources. Recent publications (e.g. Irrigation Water Management Study Committee, 2002) suggest that the Oldman River and Bow River basins could sustain expansion of irrigation by 10 and 20%, respectively. However, as climate change results in declining streamflows (see Section 3.1) and higher crop water demands (due to greater evapotranspiration and a longer growing season), these basins are expected to experience acute water shortfalls under current irrigation development. To what extent higher levels of atmospheric CO 2 will enhance the water efficiency of plants is still uncertain, and depends on the crops grown, nutrient and water availability (Van de Geijn and Goudriaan, 1996), and other factors (see Section 3.2). The use of crop varieties with greater drought tolerance is a common adaptation measure.

CASE STUDY 2

Agricultural Adaptation through Irrigation

Irrigation is the primary adaptation of agriculture in dry environments. It reduces the impacts of drought and other farm risks, supports higher crop diversity, increases profit margins and improves the long-term sustainability of smaller farm units. Irrigated agriculture is by far the largest water user on the Prairies, and small improvements in irrigation efficiency save considerable amounts of water. The Prairies have about 75% of Canada's irrigated land: Saskatchewan has 11%, and more than 60% is in southern Alberta (Irrigation Water Management Study Committee, 2002). Irrigation occurs on 4% of the cultivated land in southern Alberta's irrigation districts, where production represents 18.4% of Alberta's agri-food gross domestic product, exceeding the productivity of dryland farming by 250 to 300%. Major food-processing industries have evolved in southern Alberta, where the production of specialty crops (potatoes, beans, sugar beets) is enabled by the longer growing season, high heat units and relatively secure water supply derived mainly from snowmelt in the Rocky Mountains.

Advances in centre-pivot systems, including the irrigation of field corners and low-pressure application devices, have significantly improved the efficiency and effectiveness of irrigation. With labour savings and ability to irrigate rolling land and land 'above the ditch', the irrigated area in Alberta has more than doubled since 1970. In 2006, the irrigation infrastructure consisted of 7796 km of conveyance works (canals and pipelines) and 49 reservoirs. Off-stream reservoirs accommodate seasonal variations in supply and demand, but are not as effective as the on-stream reservoirs in meeting in-stream flow needs and apportionment. Capital costs are considerable for water distribution. For example, a plan to distribute water in eastern Alberta had an estimated price tag of $168 million using pipelines, canals and reservoirs to rejuvenate one of the most arid regions of the province (Special Areas Board, 2005). The net benefits of this project were 8 000 to 12 000 hectares (20 000 –30 000 acres) of irrigation development for an investment of $15 000 to 20 000 per hectare.

A study of irrigation requirements and opportunities was initiated in 1996 by the Alberta Irrigation Projects Association (AIPA), representing the 13 irrigation districts in Alberta, the Irrigation Branch of Alberta Agriculture, Food and Rural Development (AAFRD) and the Prairie Farm Rehabilitation Administration (PFRA) of Agriculture and Agri-Food Canada. The project report Irrigation in the 21st Century includes the following key findings:

• A move towards increased forage production to support the livestock industry, and an increased area of specialty crops for value-added processing, will result in slightly higher future water requirements than those of the current crop mix.
• On-farm application efficiency, the ratio between the amount of irrigation water applied and retained within the active root zone and the total amount of irrigation water delivered into the on-farm system, increased from approximately 60% in 1990 to about 71% by 1999. Efficiencies could approach 78% with new technologies, although a 75% on-farm application efficiency is considered to be a reasonable target for planning purposes for the foreseeable future.
• Properly levelled and designed surface irrigation systems can have efficiencies of up to 75%, whereas poorly designed and managed systems may have efficiencies less than 60%. Low-pressure, down-spray sprinklers can range in efficiency from 75 to 90%.
• Canal and reservoir evaporation losses are estimated to be about 4% of the licence volume. Decreases in evaporation losses have occurred with installation of pipelines. Although new storage reservoirs can significantly improve district operations and reduce return flows, reservoirs themselves are water users. This water use should be considered in decisions related to new storage development. Efficient storage sites that maximize the ratio of storage capacity to surface area should be given preference.
• The level of consumptive use, on average, is about 84% of that required for optimum crop yields. The level of crop water management is expected to increase in the future, assuming:
  • a further transformation of methods from surface to sprinkler irrigation;
  • a shift in irrigated crop types from cereals to higher value specialty crops;
  • that training and education of irrigation farmers on techniques and benefits of higher levels of crop water management will increase;
  • that improvements in irrigation scheduling technology and widespread use of scheduling techniques will continue; and
  • that on-farm system design will continue to improve.

The AIPA study was based on a simulation of the effects of on-farm and district water management demand variables on gross irrigation demand, and the ability of the river basins to meet that demand. Modelling was conducted for streamflow and climatic conditions in the South Saskatchewan River basin for the historical period 1928 to 1995. Even if water supply deficits occur with increasing magnitude, frequency and duration as a result of irrigation expansion, the economic sustainability of farm enterprises could still be maintained through improvements in efficiency of water use and increases in on-farm water applications. This is particularly important for those farm enterprises that can transfer water from low-value crops to higher value crops during water-deficit years.

Significant gains in on-farm application efficiencies have been realized as irrigation methods have changed and system technology has advanced. Improved on-farm irrigation management will result in future water applications meeting 90% of optimum crop water requirements for the types of crops grown and the cultural practices in southern Alberta. The water loss from irrigation reservoirs and the open channel delivery systems is still significant due to evaporation and leakage, for example, and will require even better management of limited water resources.

Whereas climate change and adaptation have yet to be explicitly addressed at the institutional level of irrigation districts and government agencies, there is evidence that adaptation and increased irrigation efficiency are being contemplated by individual irrigators (see Section 5). Some irrigators have proposed “alternatives to costly and environmentally sensitive dams” by “encouraging a study to look at the possibility of on farm storage, particularly on the corners of pivot irrigation land ” (Kent Bullock, District Manager, Taber Irrigation District, pers. comm., November 14, 2006). This additional storage would provide water for agriculture in the early and late season if required.

Economic Assessment

Results from studies on the economic impacts of climate change on Prairies agriculture are highly variable from region to region and from study to study. Some studies suggest that overall economic consequences will be negative and small (Arthur, 1988), whereas others indicate positive and large economic impacts (Weber and Hauer, 2003). Manitoba, the least water deficient province, has been projected to benefit from warming as producers shift to higher value crops, resulting in an increased gross margin of more than 50% (Mooney and Arthur, 1990). Although mostly adverse impacts were initially predicted for Saskatchewan (Williams et al., 1988; Van Kooten, 1992), this conclusion has been questioned by American studies of areas neighbouring the Prairies, which project agricultural benefits from longer growing seasons and warmer temperatures (Bloomfield and Tubiello, 2000). Similarly, studies using a land value approach (Weber and Hauer, 2003) estimate a positive impact on Prairies agriculture, with average gains in land values of $1551 per hectare, an increase of approximately 200% over the 1995 values. These land values are driven by the increase in the length of the growing season and production of more valuable crops.

Three major limitations of the available evidence on the economic impacts of climate change on agriculture are as follows:

• Most economic impact studies do not consider impacts associated with extreme climate events, such as droughts and floods, which can have devastating effects on the regional economy (see Case Study 3; Wheaton et al., 2005a, b).
• Many studies do not utilize integrated approaches, such as bioeconomic models, to estimate economic impacts of climate change on Prairies agriculture. There is a need for more integrated biophysical-socioeconomic assessment of climate change impacts. A conceptual methodology for such analysis is shown in Figure 13.
• Very few studies address livestock production. Climate change will result in both economic losses and gains in livestock production. Losses will occur through heat stress on livestock and incidence of new pests and diseases, while gains are expected from improved feed efficiency under a warmer climate.

Net agricultural economic impacts on the Prairie region would also be affected by trade linkages, both within Canada and with the rest of the world (see Chapter 9). For example, Canada's position in the production and trade of wheat and grain corn may improve relative to rest of the world (Smit, 1989; see Chapter 9). Wheat production in Canada, for instance could rise by 4.5 to 20% (Reilly, 2002).

Conclusions

Opportunities for agriculture may result from continued expansion of the growing season, increased heat units and milder, shorter winters. Negative impacts of climate change include increased frequency and intensity of extremes, such as drought and intense storms, and rapid rates of change that may exceed certain thresholds. The net impacts on agriculture are not clear and depend heavily on assumptions, including the effectiveness of adaptation. Several aspects of adaptation are poorly understood, including the process of implementation and the potential effectiveness of different approaches.

CASE STUDY 3

The 2001 and 2002 Droughts on the Prairies

Droughts have major impacts on the economy, environment, health and society. The droughts of 2001 and 2002 in Canada, which brought conditions unseen for at least a hundred years in some regions, were no exception. In general, droughts in Canada affect only one or two regions, are relatively short lived (one or two seasons) and only impact a small number of economic sectors. In contrast, the drought years of 2001 and 2002 covered massive areas, were long lasting and brought substantial impacts to many economic sectors. The 2001 and 2002 droughts were among the first coast-to-coast droughts on record, and struck areas that are less accustomed to dealing with water scarcity. Although national in scale, the droughts were concentrated in western Canada, with Saskatchewan and Alberta being the hardest hit provinces (Wheaton et al., 2005a, b). Repercussions of the droughts were far reaching, and included the following:

• Agricultural production dropped an estimated $3.6 billion for the 2001 and 2002 drought years, with the largest loss in 2002, at more than $2 billion.
• The gross domestic product was reduced by some $5.8 billion for 2001 and 2002, again with the larger loss in 2002, at more than $3.6 billion.
• Employment losses exceeded 41 000 jobs, including nearly 24 000 jobs in 2002.
• Production losses were devastating for a wide variety of crops across Canada. Alberta's lost crop production was about $413 million in 2001 and $1.33 billion in 2002. The estimated value of reduced crop production in Saskatchewan was $925 million in 2001 and $1.49 billion in 2002.
• Net farm income in 2002 was negative in Saskatchewan and zero in Alberta.
• Severe wind erosion events occurred, even with the improvements provided by conservation tillage.
• Livestock production was especially difficult due to the widespread scarcity of feed and water.
• Water supplies that were previously reliable failed to meet requirements in some areas, necessitating numerous adaptation projects, ranging from repairing existing dams, dugouts and wells to developing new dugouts and wells. Livestock were culled or moved to areas where forage and water were more accessible. Communities required supplemental water from various sources. These adaptations resulted in additional costs to the communities, and crop and livestock production losses.
• There was a pronounced decrease in the growth of aspen forests, and a massive dieback of aspen and other trees in the most strongly drought-affected areas in western Canada. Planted birch, ash and other trees in urban areas, such as Edmonton, were also severely affected (Hogg et al., 2006). A major collapse in aspen productivity likely occurred during this drought (Hogg et al., 2005).
• Multi-sector effects occurred, with documented impacts on agricultural production and processing, water supplies, recreation, tourism, health, hydroelectric power generation and transportation.
• Long-lasting impacts included soil and other damage by wind erosion, and deterioration of grasslands.

Several government response and safety net programs partially offset negative socioeconomic impacts of the 2001 and 2002 drought years. These and other adaptation measures, some costly and disruptive, were used to address these impacts. Many adaptations proved insufficient to deal with such an intense and persistent drought over such a large area. Since more intense and longer droughts are projected for the Prairies in future, these recent impacts underline western Canada's vulnerability and the need to enhance adaptive capacity in all areas.

4.2 FORESTRY

Forest Operations and Management

Short-term climate events can affect forest operations and access to harvestable wood supplies. Impacts include flooding, leading to the loss of roads, bridges and culverts; higher winter temperatures, which affect the duration of frozen ground for winter operations, including the ability to construct and maintain ice roads (see Section 4.3); and water-logged soils in cut blocks, which prevent equipment operations (Archibald et al., 1997). In wet areas or periods of high precipitation, soils may be deeply rutted by equipment operations, affecting long-term site productivity, ability to regenerate the site and the potential for erosion (Archibald et al., 1997; Grigal, 2000). Steep topography can exacerbate these conditions and may lead to landslides (Grigal, 2000). Other impacts result from improper maintenance of roads, resulting in increased slope erosion, and of water-control structures, causing waterlogged soils and flooding. Forest operations are often carried out in winter because the frozen soil is relatively impervious to the impact of heavy equipment (Grigal, 2000). Flooding or severe erosion caused by extreme precipitation events can reduce or eliminate the opportunities for rehabilitation of temporary forest roads (Van Rees and Jackson, 2002). Road crossings over creeks and rivers affect water quality and fisheries habitat by introducing sediment, but these effects are generally minor, except under extreme events (Steedman, 2000). Current adaptive responses to these conditions include the use of high-flotation tires on logging equipment for wet soil conditions (Mellgren and Heidersdorf, 1984); reallocating harvest operations to drier sites; and switching from winter to summer operations. However, equipment modifications can be expensive and difficult to maintain.

In the long term, climate affects the growth and continued productivity of forest stands. Temperature, moisture and nutrient availability, and atmospheric CO 2 concentrations all affect tree growth directly (Kimmins, 1997). In managed forests, planted seedlings are climate sensitive, and natural regeneration following disturbance is highly sensitive to climate in the early stages of establishment (Parker et al., 2000; Spittlehouse and Stewart, 2003). Climatic factors, mediated by soils and topography, also affect the species composition of forest stands and landscapes (Rowe, 1996).

Forest productivity and species composition at the landscape level are also affected by large-scale disturbances, which are strongly influenced by climate. For Canadian forests, the most important disturbance agents are forest fires (Weber and Flannigan, 1997) and insect outbreaks (Volney and Fleming, 2000). For example, insect pests in the Prairies affected an average of 3.1 million hectares per year between 1975 and 2003, with extreme values of 10 to 12 million hectares in the mid-1970s (National Forestry Database Program, 2005). Forest fires in the Prairies burned an average of slightly less than 1 million hectares per year between 1975 and 2005, but this figure reached 3 to 4 million hectares during some years in the 1980s (National Forestry Database Program, 2005).

To assess ecosystem impacts in commercial forests, comprehensive ecosystem models are required that include both local-scale ecosystem processes (e.g. productivity) and landscape-scale processes (e.g. seed dispersal, disturbance). These dynamic global vegetation models can be used as stand-alone simulators or can be coupled to global climate models. Examples include the Integrated Biosphere Simulator (IBI; Foley et al., 1996), Lund-Potsdam-Jena model (Gerber et al., 2004) and MC1 (Bachelet et al., 2001). Further regional-scale application of these models is needed, including detailed parameterization and validation of results. This approach has been applied in several recent European forestry assessments (Kellom äki and Leinonen, 2005; Schröter et al., 2005; Koca et al., 2006).

Future Vulnerabilities

Climate scenarios for the Prairies suggest the future will bring warmer winters with greater precipitation, earlier springs, and summers with reduced soil moisture (see Section 2.5). Under these conditions, transportation in spring on forest roads may be reduced. Erosion at susceptible sites (e.g. road crossings) is likely to increase in response to higher and more intense precipitation (Spittlehouse and Stewart, 2003). Flooding would remain a concern and would necessitate closer attention to sizing of culverts and other water-control structures (Spittlehouse and Stewart, 2003). In areas where winter operations are important, the shorter period of frozen ground conditions will limit woods operations and affect scheduling of harvesting equipment among cutting areas. Potential adaptation measures for dealing with such changes, and other climate impacts, are listed in Table 10.

TABLE 10: Examples of adaptation measures for forest management, as identified by Spittlehouse and Stewart (2003)

Gene management	Breeding for pest resistance and climate stresses and extremes
Forest protection	Altering forest structure and developing ‘fire smart' landscapes (i.e. creating areas of reduced flammability through fuel modification)
Forest regeneration	Assisting the migration of commercial tree species from present to future ranges through artificial regeneration
Silvicultural management	Pre-commercial thinning to enhance growth and insect/disease resistance
Protection of non-timber resources	Minimizing fragmentation of habitat and maintaining connectivity
Park and wilderness area management	Managing these areas to delay, ameliorate and direct change

Higher temperatures increase the rate of both carbon uptake (photosynthesis) and carbon loss (respiration), so the effect of higher temperatures will depend on the net balance between these processes (Amthor and Baldocchi, 2001). Both photosynthesis and respiration have been shown to adjust to a change in environmental conditions (acclimation), so any increases may be short lived. Changes in photosynthesis have been shown to be highly dependent on nutrient (especially nitrogen) and water availability (Baldocchi and Amthor, 2001). Generally, net primary productivity is expected to increase under warmer temperatures and longer growing seasons, if water and nutrients are not limiting (Norby et al., 2005).

Soil temperatures are also likely to increase. Although no soil warming studies have been conducted on the Prairies, experimental soil warming in northern Sweden (64 °N) resulted in increased basal area growth and demonstrated that the addition of fertilizer and water dramatically increases volume growth relative to warming alone (Stromgren and Linder, 2002). In a wide-ranging review of other soil warming experiments, increased rates of nitrogen availability have been found in nearly all locations and vegetation types (Rustad et al., 2001). However, this is dependent on water availability, and will also be affected by nitrogen deposition from industrial sources (Kochy and Wilson, 2001).

Much of the southern boundary of the boreal forest in the Prairies is currently vulnerable to drought impacts, and this vulnerability is expected to increase in the future (Hogg and Bernier, 2005). Available water-holding capacity (AWC) of the soil is a critical factor in determining water availability for uptake by the trees' root systems. Simulated future drought reduced productivity of white spruce in Saskatchewan by about 20% on sites with low AWC (Johnston and Williamson, 2005).

Higher levels of atmospheric CO2 improve water-use efficiency (WUE); that is, less water is lost for a given unit of CO 2 uptake (Long et al., 2004). Increased WUE could be particularly important on water-limited sites, such that tree growth might continue where it would be severely limited under current CO 2 levels. Johnston and Williamson (2005) found that, even under severe drought conditions, increased WUE under a high CO 2 future would result in an increase in productivity relative to current conditions. Free-air CO 2 enrichment (FACE) experiments expose trees to levels of CO2 roughly twice that of the pre-industrial period. In one such experiment, an initial increase in net primary production (NPP) was observed for loblolly pine, but was relatively short lived (3 –4 years) and only occurred when soil nutrient and water levels were relatively high (DeLucia et al., 1999; Oren et al., 2001). Trees were found to respond to increased CO 2 concentrations more than other vegetation, with biomass production increasing an average of about 20 to 25% (Long et al., 2004; Norby et al., 2005).

The effect of climate change on disturbance regimes could be considerable. For the Prairies region, forest fires are expected to be more frequent (Bergeron et al., 2004), of higher intensity (Parisien et al., 2004) and to burn over larger areas (Flannigan et al., 2005), although the magnitude of these changes is difficult to predict. Insect outbreaks are also expected to be more frequent and severe (Volney and Fleming 2000). Of particular concern is the mountain pine beetle, currently in a major outbreak phase in the interior of British Columbia (see Chapter 8). It is now beginning to spread east, with approximately 2.8 million trees affected in Alberta as of spring 2007 (Alberta Sustainable Resource Development, 2007). The beetle is limited by the occurrence of -40 °C winter temperatures: with warming, this limiting temperature is likely to occur farther to the north and east, allowing the beetle to spread into jack pine in the Prairies. Jack pine's distribution is nearly continuous from Alberta to New Brunswick, so the spread of the beetle across the Canadian boreal forest is a possible future scenario (Logan et al., 2003; Carroll et al., 2004; Moore et al., 2005; Taylor et al., 2006). The long-term effect of insect outbreaks on forest management is difficult to predict, although increased tree mortality in the southern margin of the boreal forest is projected as a result of the interaction of insects, drought and fire (Hogg and Bernier, 2005; Volney and Hirsch, 2005).

Increased rates of fire disturbance will differentially affect tree species due to differences in flammability and their ability to regenerate (Johnston, 1996). Some coniferous species are inherently more flammable than hardwood species (Parisien et al., 2004), so increased forest fire activity will likely favour hardwood species (e.g. aspen) over some conifers (e.g. white spruce). As a result, wood supply to oriented strand board (OSB) mills in Canada, which generally use 90 to 100% hardwood (mainly aspen) as feedstock, would not be as affected by increased forest fires as saw mills that depend on fire-susceptible softwood species for lumber production.

Economic and Social Impacts

Climate change impacts outside the region will have implications for the Prairies forest industry. Given the importance of forest products to the building sector, increases in natural disturbances could stimulate the forest products sector. For example, the price of oriented strand board panels went up by more than 50% in the weeks following Hurricane Katrina in the fall of 2005 (National Association of Home Builders, 2005). On sites with adequate water and nutrients, increased tree growth may result in an increased wood supply. This could depress the market price but provide a benefit to consumers (Sohngen and Sedjo, 2005). Alternatively, large-scale disturbance and tree dieback could reduce the wood supply, thereby increasing prices and leading to local or regional wood shortages (Sohngen and Sedjo, 2005). Associated impacts could include mill closures and the attendant economic effects on small forest-dependent communities (Williamson et al., 2005). Changes in species composition due to disturbance and growth conditions in the future may require mills to change processing capacity and introduce new products. Salvage harvesting following large-scale disturbances may provide additional woody biomass for use in bioenergy production; this is currently being considered in British Columbia for forests affected by the mountain pine beetle (Kumar, 2005; see Chapter 8). However, impacts of intensive salvage harvesting on ecosystem function and biodiversity may be negative (Lindenmayer et al., 2004).

4.3 TRANSPORTATION

The transportation network in the Prairies is extensive and diverse. The public road network consists of more than 540 000 km of two-lane-equivalent roads, accounting for 52% of the national total (Transport Canada, 2005). About 20% of the road network is paved. Several thousand kilometres of public winter (ice) roads are built each year in the region, mostly in Manitoba, where some 2300 km of winter roads provide access to communities not serviced by permanent roads (Manitoba Transportation and Government Services, 2006). The railway network (Figure 14) is also important the region, and includes a railway to the region's only ocean port at Churchill, Manitoba. Fifty-one airports were in operation in the region in 2004 (Statistics Canada, 2004).

Transportation is a vital component of almost all economic and social activities, and transportation systems are very sensitive to extreme weather events (Andrey and Mills, 2003a). With climate change resulting in warmer winter temperatures, it is likely that more of the cold-season precipitation will come in the form of rain or freezing rain. Increased frequencies of extreme precipitation events (Kharin and Zwiers, 2000) and increased inter-annual climate variability are likely to result in increased damage to roads, railways and other structures as a result of flooding, erosion and landslides.

Some climate changes may result in economic savings, such as reduced need for road snow clearing, whereas other changes may require significant capital investments, such as improvements to storm-water management (IBI Group, 1990; Marbek Resource Consultants, 2003). Since weather is a key component of many transportation-related safety issues, including automobile and aircraft accidents, climate change will affect the risks associated with the transportation of people and goods, and perhaps the associated costs of insurance. The demand for transportation may also be affected, since many of the region's transportation-sensitive sectors, including agriculture, energy and tourism, will also be impacted by climate change.

Infrastructure Impacts

Each component of the extensive and diverse transportation infrastructure of the Prairies requires proper design, construction and maintenance to operate as safely and reliably as possible over its design lifetime. There are significant costs associated with transportation infrastructure, most incurred by local, municipal, provincial and federal governments. Private companies and corporations also have major investments in transportation infrastructure, such as in the railway industry.

Arguably, the most significant negative impact of climate change on transportation infrastructure in the Prairies is related to winter roads (see Case Study 4). Winter roads are a vital social, cultural and economic lifeline to remote communities (Kuryk, 2003; Centre for Indigenous Environmental Resources, 2006). Shipping bulk goods by air is prohibitively costly; thus, the threats that changing climate poses to winter road operations is a concern to each of the provincial governments mandated to provide surface transport, as well as to the communities currently serviced by these roads. During the warm El Ni ño winter of 1997–1998, $15 to 18 million were spent airlifting supplies into remote communities in Manitoba and northern Ontario because winter roads could not be built or maintained for sufficient periods of time (Paul and Saunders, 2002; Kuryk, 2003).

In contrast, the warmer winters may result in substantial reductions in the costs associated with non –ice road infrastructure. Cold temperatures and frequent freeze-thaw cycles cause much of the deterioration of paved and non-paved surfaces (Haas et al., 1999). In the southern parts of the Prairies, where the vast majority of the permanent road surfaces are found, reductions in the length and severity of the frost-affected season could result in long-term cost savings associated with repairs and maintenance. However, winter warm spells or increased inter-daily temperature variability may cause the frequency of freeze-thaw cycles to increase, if only during a period of a few decades, while winters become warmer. Additionally, in some northern areas, paved roads are stabilized by frozen substrates during winter, and may therefore be compromised by warmer winter temperatures.

Increases in mean temperature and the frequency of hot days during summer are expected to lead to increased road-related infrastructure costs. Asphalt-covered surfaces, particularly those with large amounts of heavy truck traffic, are especially susceptible to damage during heat waves. Potential problems include rutting of softened surfaces, and the flushing and bleeding of liquid asphalt from poorly constructed surfaces (Lemmen and Warren, 2004). Of these, rutting is the most serious and costly type of damage to repair. Each is largely preventable with proper design and construction practices. To date, it is not clear which is likely to be greater in the region: savings associated with less frost-related damage to roads or the costs of increased damage to roads due to warmer summer temperatures.

Maintenance of railway infrastructure is likely to cost less as a result of warmer winter temperatures. Extreme cold temperatures cause broken railway ties, failure of switches and physical stress to railway cars; thus, fewer extremely cold temperatures should result in smaller costs associated with these problems. In the summer, however, rail damage caused by thermal expansion (Grenci, 1995; Smoyer-Tomic et al., 2003) will likely increase as heat waves become more frequent. More significant, perhaps, is the likelihood that northern railways with lines passing through areas of permafrost, such as the one serving the Port of Churchill in northern Manitoba, will require frequent and significant repair, if not replacement, as a result of continued permafrost degradation (Nelson et al., 2002).

CASE STUDY 4

Winter Roads in Northern Manitoba

The most significant negative impact of climate change on transportation infrastructure in the northern part of the Prairies is related to winter roads. In Manitoba, where the majority of the region's winter roads are built, more than 25 000 people in 28 communities rely on winter roads (Centre for Indigenous Environmental Resources, 2006). The population of these communities is expected to double in the next 20 years. Some 2300 km of winter roads are built annually to provide access to communities not serviced by permanent roads (Manitoba Transportation and Government Services, 2006).

Winter roads are vital links between northern Aboriginal communities and to other parts of Canada. They are social, cultural and economic lifelines in remote communities, enabling the delivery of such essential goods as food, fuel, and medical and building supplies (Kuryk, 2003; Centre for Indigenous Environmental Resources, 2006). There are also safety-related issues, since many northerners use winter roads and trails for hunting, fishing and cultural and recreational activities (see Section 4.4).

In its study of five First Nations in Manitoba (Barren Lands, Bunibonibee Cree, Poplar River, St. Theresa Point and York Factory Cree), the Centre for Indigenous Environmental Resources (2006) reported the following key issues:

Reliability of Winter Roads

Northern communities perceive the two most common causes of poor winter road conditions to be 1) warmer weather (attributed to both natural cycles and human-induced climate change), and 2) high, rapidly fluctuating water levels with strong currents (attributed to flow-control structures and naturally high runoff). Poor conditions include:

• weaker and thinner ice;
• shortened and delayed winter road seasons;
• excess slush, earth patches, potholes, hanging ice and ice pockets on roads; and
• less direct routes than those that cross water bodies.

With climate change, the average length of the winter road season in Manitoba is expected to decrease by 8 days in the 2020s, 15 days in the 2050s and 21 days in the 2080s (Prentice and Thomson, 2003).

Winter Road Failure and Emergency Management

Manitoba Transportation and Government Services (MTGS) has reported decreased ice thickness, poor ice texture and density, delayed winter road seasons, problematic muskeg areas and decreased load limits. There have been cases of equipment damaged beyond repair from a single trip on the winter road. Emergency responses to winter road failure, including the airlifting of supplies, are costly, as described previously for the warm winter of 1997 –1998.

Personal Safety on Winter Roads, Trails and Frozen Water Bodies

When winter road seasons are short, some community members take additional risks on winter roads, trails and water bodies. A road construction worker from Wasagamack First Nation drowned in 2002 when the grader he was driving broke through the ice.

Personal Health Concerns

There are concerns about access to health centres and other medical assistance when winter roads and trails are not available. In addition, high rates of diabetes in Aboriginal communities have been linked to decreased access to affordable healthy foods, whether from stores or from the wild. Stress is another health-related concern with connections to shortened winter road seasons, in terms of increased financial pressures and greater social isolation.

High Cost of Living

Transportation by winter roads minimizes the cost of fuel, goods and services. The cost of shipping goods by air is two to three times greater than that for ground transportation on winter roads. Lower prices also are available at larger centres accessible via all-weather roads. The cost of food is a significant issue, given that unemployment rates in northern communities are as high as 80 to 90%. Accessing wild meat and fish allows individuals to offset the high cost of food at the local store, but warmer winters are restricting the gathering of traditional foods (see Section 4.4).

Decreased Participation in Social and Recreational Activities

Winter roads, access trails and frozen waters play important social and cultural roles in northern communities. They provide access to neighbouring communities and larger centres to shop, visit with friends and family, gather for social events (e.g. marriages, births and funerals), participate in recreational activities (e.g. bingos, festivals and fishing derbies) and visit friends, family or the elderly in hospitals or care facilities.

Furthermore, community members use trails for recreational riding. In recent years, some fishing derbies and winter carnivals have had to be cancelled. Overall, individuals feel more disconnected from their friends and relatives in neighbouring communities when winter road seasons are shorter and less reliable. Helicopter flights are available, but most cannot afford the high fares.

Hindrance of Community Operations and Economic Development

Much economic activity is related to access provided by frozen ground and water bodies. Thin ice cover and poor winter road conditions have restricted some income-generating activities, including commercial ice fishing and the export of resources (e.g. fish and furs) for sale in larger centres. Winter roads enable communities and businesses to more efficiently acquire goods and supplies required for regular operations, maintenance and repairs. Also, the winter roads provide First Nations with income generated from road construction and maintenance contracts with MTGS. Thus the length and timing of winter road operations can impact economic development, housing, capital, special projects and equipment maintenance.

The Centre for Indigenous Environmental Resources (2006) recommended a variety of actions at the community and government levels to address issues related to degrading winter roads. These can be summarized as follows:

• Increase security of winter roads (both levels).
• Develop community climate change action plans (community) and provide support for implementing these plans (government).
• Develop a communication strategy (community) and increase communication with other First Nations (government).
• Increase social and cultural-recreational opportunities (community) and provide support for these opportunities (government).
• Increase consumption of local foods (community) and provide support for consumption of these foods (government).
• Enhance community safety (both levels).
• Increase funding opportunities for community operations (both levels).

Sea-level rise will impact the shores of Hudson Bay (Overpeck et al., 2006), even though the land is rising due to a high rate of glacioisostatic rebound.The Port of Churchill and its associated facilities may experience more frequent and severe erosion by water and ice, which would affect shipping infrastructure. On the other hand, the significantly longer ice-free season in Hudson Bay and northern channels resulting from continued climate warming (Arctic Climate Impact Assessment, 2005) will increase opportunities for ocean-going vessels to use the Port of Churchill as a point of departure and arrival for grain and other bulk commodities (see Chapter 3).

Operations and Maintenance

Climate change will potentially affect transportation service availability, scheduling, efficiency and safety (e.g. Andrey and Mills, 2003b). All modes of transport are at least occasionally unavailable, or schedules are disrupted, due to weather-related events. The majority of weather-related delays and cancellations occur in the winter, usually as a result of heavy snowfalls, blizzards and freezing rain, but also as a result of extreme cold snaps. As warmer winters will be associated with fewer cold snaps, there should be fewer and shorter delays related to this type of event in the future.There is some evidence that a warmer climate will be associated with fewer and less intense blizzards (Lawson, 2003). If this is correct, there may be substantial savings to the transportation industry, particularly in the airline and trucking sectors. For trucking, there are often significant costs and penalties associated with delayed shipments of, for example, perishable produce.

A warmer climate may result in fewer weather-related accidents, injuries and fatalities (Mills and Andrey, 2002), particularly in the winter, if snowfall events become less intense and frequent. Traffic accidents are strongly and positively correlated with precipitation frequency (Andrey et al., 2003). A reduction in the number of blizzards on the Prairies has already been reported (Lawson, 2003). Snowfall events account for a large proportion of the reductions in road traffic efficacy and safety in Canada (Andrey et al., 2003), and are associated with large road-clearing expenditures. For example, in the winter of 2005–2006, the Manitoba government conducted 1 455 193 pass kilometres of snow clearing and 220 945 pass kilometres of ice blading; almost 57 000 tonnes of de-icing chemicals were applied to provincial highways; and 42% of the year's $80 million in road maintenance expenditures was spent in the winter (Manitoba Transportation and Government Services, 2006). Thus, warmer winters with fewer snow events may substantially lower costs associated with the removal of snow and ice from roads (e.g. IBI Group, 1990; Jones, 2003), and the application of less salt on icy roads may substantially reduce damage to vehicles, bridges and other steel structures (Mills and Andrey, 2002). However, these potential savings are very temperature sensitive, and it remains possible that the number of days requiring the application of salt may, in fact, increase if there is an increase in the number of days with freezing rain. Even if the total amounts of precipitation do not change substantially, it is generally acknowledged that the frequency of extreme precipitation events will increase (Groisman et al., 2005), that more of the winter precipitation will fall as rain (Akinremi et al., 1999) and that the distribution of precipitation throughout the year will change (Hofmann et al., 1998). Increased frequency of extreme precipitation events in the summer would likely increase the frequency of road accidents. Intense precipitation and excess water also hinder transportation operations. For example, increased and more intense precipitation in the mountains would likely result in a higher incidence of flash floods and debris flows (see Section 3.3), thereby disrupting key transportation links. Associated with increased storminess would be an increase in the frequency of extreme winds, which would cause air transport delays and risks.

4.4 COMMUNITIES

The vulnerability of communities on the Prairies to climate change varies due to relative differences in adaptive capacity and direct exposure to potential impacts. To assess adaptive capacity, it is necessary to consider social, cultural, economic and institutional characteristics (Davidson et al., 2003; see Chapter 2). Historically, societies have shown a remarkable ability to adapt to local climatic conditions (Ford and Smit, 2003), but repeated or continuous stressors, such as those posed by climate change, can increase vulnerability, particularly when they occur in combination with other stress-inducing factors and at high enough frequencies to prevent recuperation.

Urban Centres

Most of the population on the Prairies is concentrated in a few metropolitan centres, although the size of the cities is relatively small, with only Calgary approaching one million residents. Overall, major urban centres generally have greater levels of adaptive capacity than smaller cities and rural communities. Cities have well-developed communication and transportation infrastructure; in most cases, they have economic reserves and well-developed emergency response capacities, and tend to have greater political influence (Crosson, 2001). However, a study of the adaptive capacity of cities in the Prairies found a lack of knowledge and awareness among decision-makers of the potential impacts of climate change and of the need for
adaptation (Wittrock et al., 2001).

The primary climate impacts of concern for cities on the Prairies are extreme weather events, drought, disease, heat stress and the gradual ecological transformation of urban green space.

Extreme weather: Flood control may be the most significant climate-related concern for urban areas (Wittrock et al., 2001). Cities were not historically planned for flood prevention, such that many neighbourhoods are located in flood-prone areas and existing risk management approaches are often inadequate. Existing water management infrastructure (storage and drainage systems) may not be suited to projected future changes in precipitation and snowmelt.

Drought: Cities are generally more insulated from the effects of drought than are rural communities, having more sophisticated water acquisition and storage infrastructure. Nonetheless, projected increases in the magnitude and frequency of drought will certainly impact water supply and utilization in cities on the Prairies, and place an emphasis on water efficiency initiatives.

Heat stress: Heat stress associated with increasing global temperatures is exacerbated in cities due to 'heat island' effects (e.g. Arnfield, 2003). Although the highest temperatures ever recorded in Canada are from the Prairies, this heat is rarely associated with high humidity. This has resulted in relatively limited adoption of policies and technologies to deal with heat stress, such as residential air conditioning and city shelters. Cities on the Prairies also are not associated with air pollution levels typical of urban centres in Ontario and Quebec, and are therefore less likely to suffer the cumulative effects of heat stress and heavy air pollution (see Chapters 5 and 6). Nonetheless, extreme heat days are significant in Prairie cities, particularly for the more vulnerable populations.

Green space: Urban green spaces are susceptible to long-term shifts in both average temperatures and precipitation, thus making existing species poorly suited to emergent climate trends and more acute events, such as drought, which can place vegetation and wildlife under extreme stress. One significant expense for Prairie cities during the most recent drought (2000 –2002) was the loss of ornamental trees. For example, the City of Edmonton (2007) estimated that they have lost approximately 23 000 trees since 2002 as a result of drought; they have resources to replace approximately 8 300 of these trees.

Rural Communities

Thirty-six percent of the population of Saskatchewan and 28% of Manitoba's live in rural communities. Alberta is more urbanized, with only 19% of the population in rural areas. Some rural communities are experiencing rapid population and economic growth, while others, particularly many agricultural communities in the southern Prairies, are in decline. Few rural communities have access to the same level of disaster management resources (e.g. emergency response and health care programs) as larger cities. For remote northern communities, transport of materials and supplies into the community, or transporting residents out of the community in times of hazard, becomes a limitation due to the small number of transport routes. In a small town, moreover, even a modest hazardous event can be locally disastrous, simply because it is likely to affect a greater proportion of the population (the 'proportionality impact'; Mossler, 1996).

In general, rural communities are also more sensitive to climate change impacts than cities, largely due to their economic dependence on natural-resource sectors and lack of opportunities for economic diversification. More than 25% of the jobs in rural communities in Canada are in resource-based industries, and a far greater proportion of employment is indirectly dependent upon these sectors. In the Prairies region, 78% of resource-related jobs are in agriculture (Stedman et al., 2005). Many rural communities on the Prairies are already stressed due to both climate events, such as the 2001 –2002 drought, and non-climatic stresses, such as softwood lumber trade issues and outbreaks of bovine spongiform encephalopathy (BSE). These communities are therefore simultaneously characterized by a reduced coping range — as community and household economic and social capital reserves are exhausted — and a reduced likelihood of engaging in proactive planning, due to the low degree of salience that may be placed on climate change relative to other, more immediate stressors.

Most rural communities in the region are located in the Prairie Ecozone. The risks and opportunities for agricultural communities are strongly tied to climate change impacts on agriculture, as described in Section 4.1. Climate change impacts of greatest concern include extreme weather events, droughts and ecosystem shifts. Drought is of particular concern, as rural communities are largely dependent on well water or smaller reservoirs that can dry up during severe drought. It is broadly acknowledged that there is relatively high potential adaptive capacity in the agricultural sector, involving both farm- and sector-level adaptations. With recent agricultural restructuring and the trend towards larger farms, many communities have experienced a significant exodus of their younger population, such that the average farmer in Canada is 55 years old (Voaklander et al., 2006). An aging farm population may be less innovative in terms of willingness to implement new adaptive measures, while industrial-scale farms have more capital but not necessarily the same level of commitment to the sustainability of local communities.

Forest-based communities, primarily in the Boreal Ecozone, make up a small proportion of rural communities, with the forest sector accounting for about 2% of regional employment in the Prairies (Stedman et al., 2005). The forest industry in Alberta is significantly larger than in Manitoba or Saskatchewan. Given the potential impacts of climate change on forest ecosystems (see Section 3.2) and commercial forestry (see Section 4.2), forest-based communities will face a great degree of uncertainty (Mendis et al., 2003). They also may be vulnerable because of the relative inflexibility of modern industrial forestry, particularly in the Prairies, whose forest industry is relatively young. The region is characterized by large forest management areas managed under 10-year planning horizons, and modern, high-capacity processing facilities that may only be suitable for one or two species. As with other rural communities, forest-based communities may also be severely constrained with respect to emergency response capacity. Many forest-based communities are located in remote regions with limited transportation access, which can be a liability if extreme weather or forest fires compromise the primary transportation routes.

Mining- and energy-based communities, primarily in the Boreal and Taiga ecozones, could be vulnerable given the impacts of climate change on these sectors (see Section 4.6). Of particular concern are projected reductions in water supplies, as many processes in these sectors are heavily water dependent. Other factors include disruptions to power supplies and transportation networks serving remote communities in the north. Rapid population growth in some energy-based communities, such as Fort McMurray, AB, may exacerbate vulnerability to climate change, as the demands have already exceeded existing infrastructure of all sorts, including basic housing. Social services may be stretched, particularly when many of the incoming residents are from diverse cultural backgrounds. Consequently, the ability to respond to extreme weather events, forest fires and health risks is a significant concern. Rapid growth also has a deleterious effect on social integration and community satisfaction, both of which affect the ability to respond to unanticipated crises. Communities with stable populations tend to recover better from crises.

Several Prairie communities have strong economic reliance on tourism and nature-based recreation activities. The potential economic impacts of climate change on tourism are most acute in Alberta, whose tourism industry generated more than $4.96 billion in revenue for the province in 2005 (Alberta Economic Development, 2006), mostly related to national and international visitors to the national parks in the Canadian Rockies. Banff alone has received between 3 and 5 million visitors per year during the past decade (Service Alberta, 2005). Nature-based tourism, and the communities that depend on this industry, face several challenges as climate change impacts ecosystems (see Section 3.2) and the related outdoor recreation (see Section 4.7). The parks most severely affected, with local economic impacts, are the island forests (see Case Study 1) and small recreation areas of the southern Prairies, where the water and trees that draw visitors are particularly sensitive to changing climate (Figure 15). Aboriginal communities have the highest rates of poverty and unemployment throughout the Prairies. Approximately half of the Prairies Aboriginal population lives in cities; the remainder live in or near their traditional territories, which are directly exposed to the impacts of changing climate on ecosystems, water and forestry (see Case Study 5). Many Aboriginal communities are also at least partly dependent on subsistence activities for their livelihood, with local food supplies supplementing their diets to a far greater extent than for non-Aboriginal people. Impacts of climate change have implications for flora and fauna, and declines or annual uncertainties in the availability of moose, caribou, deer, fish and wild rice will increase dependence on imported foods, with both economic and health implications for residents. Residents are already concerned about decreased participation in subsistence activities owing to difficulties in accessing reserve lands and traditional territories in winter. Unsuitable snow and ground conditions greatly hamper travel, by foot or by snowmobile, to trap lines, hunting grounds and fishing areas. Communities report decreased levels of these traditional activities due to concerns about personal safety.

CASE STUDY 5

First Nations' Traditional Ways of Life and Climate Change: The Prince Albert Grand Council (PAGC) Elders' Forum, February 2004

Aboriginal people of the Prairies region, and Elders in particular, are contributing their knowledge about climate change, particularly in northern regions where livelihood activities remain tied to the land. Recent initiatives point to the growing need for collaboration between researchers and Aboriginal communities to understand and address climate change issues. The Prince Albert Grand Council (PAGC) Elders' forum on climate change in February 2004 (Ermine et al., 2005) was based on respectful learning and traditional protocols, in which Elders from the PAGC area shared information about climate change with one another and with members of the research community. For the most part, the observations of the PAGC Elders reinforced, confirmed and enhanced scientific observations. Elders brought forward the collective wisdom of generations living in specific locations, adding depth to the scientific view of climate change impacts and adaptation. The Elders relate to climate change as a broader process that encompasses the sociocultural aspects of their lives. They spoke of the land with passion, honouring a way of life that provides for their health and well-being through, for example, trapping, hunting and fishing.

Observations of Changes and Impacts

The Elders recognized that annual variability is part of the normal pattern of nature. However, they identified several trends of concern, including the following:

• Extreme weather events, such as tornadoes and hailstorms, have occurred more frequently in recent years.
• Shifts in seasonal characteristics were felt to be more worrisome, and indicative of the more serious nature of climate change, than isolated climate events. For example, summer and autumn seasonal conditions were observed to extend farther into the traditional 'winter' months.
• Recently, summers were observed to be abnormally dry, with rainfall having no appreciable effect on moisture levels.
• The quantity and quality of water is deteriorating in their territories, in part due to human activity.
• A general imbalance in nature, reflected in the condition of wildlife and inferred from abnormal wildlife behaviour, includes changes in migration patterns and population ranges within their territories.
• New species are starting to inhabit areas where they were not previously seen. These include previously uncommon birds being observed more frequently and animals (e.g. cougars and white-tailed deer) wandering into areas far from their usual ranges.
• Increased summer heat is affecting the health of children and the elderly.
• Unpredictability of weather is influencing their preparedness for outdoor activities.
• Plants, including trees and berry-producing shrubs, are showing the effects of heat and associated drought, such that useful products from these sources are no longer as abundant.
• Decreases in the quality and thickness of the winter coats of fur-bearing animals are affecting the livelihood of northern people engaged in trapping.

Adaptation and Adaptive Capacity

The Elders trust that patterns of climate are part of existence. They have always lived within the patterns of nature. Prophesies would have been a traditional mechanism for adaptation, preparing people for the future. As an example, an Elder recounted behaviours of bees that presaged the kind of winter to expect. Animal behaviour is acutely observed and used as the basis for predictions.

Sustaining connections to the land and environment is an important foundation for healthy individuals and communities. When people become disconnected from the land, the lines of communication between the natural and social worlds are severed. Elders expressed a strong sentiment that it was their responsibility to keep and protect the land for future generations. They wished to take action, but were concerned about their ability to influence the activities of industrial corporations. Co-operation between sectors of society was strongly emphasized. The forum itself was considered part of the solution, and Elders expressed appreciation for the involvement of western scientists in the discussion of climate change.

The Elders deliberately refrained from making resolutions and formal recommendations. They identified their role as strengthening their own local communities and cultural connections to the land, particularly by working with youth. One of the results emerging from the Elders' forum was the way that climate change is framed. From the Elders' perspective, global changes have been singularly isolated and prematurely labelled by western scientists as the primary dimension of 'climate change', with the result that the human realm has been largely removed. The value of the Elders' perspective is to reprioritize the human element, in terms of both impacts and responsibility.

4.5 HEALTH

Human health and well-being are intimately linked to climate and weather patterns. Under climate change, the populations of the Prairies may experience additional negative health burdens from air pollution, food-borne pathogens, heat-related illnesses, poor mental health, particulate matter, water-borne pathogens and vector-borne diseases (SeÅLguin, in press). Subpopulations most at risk for negative health consequences are children, the elderly, Aboriginal peoples, those with low socioeconomic status, the homeless and people with underlying health conditions. Aspects of changing climate that directly and indirectly affect health and well-being of Prairies residents include drought, flooding, ecosystem changes and increased temperatures.

Drought

Drought reduces surface waters, leading to increased concentration of pathogens and toxins in domestic water supplies (Charron et al., 2003; World Health Organization, 2003). It enhances dust production from open sources (e.g. unpaved roads, fields and forest fires), which makes up 94% of particulate matter emissions in Canada (Smoyer-Tomic et al., 2004). The major health effect from inhaling dust is airway inflammation, manifesting as asthma, allergic rhinitis, bronchitis, hypersensitivity pneumonitis and organic dust toxic syndrome (do Pico, 1986; Rylander, 1986; do Pico, 1992; Lang, 1996; Simpson et al., 1998).

Drought exacerbates wildfires (Smoyer-Tomic et al., 2004), which are associated with increases in respiratory conditions, hospital visits and mortality (Bowman and Johnston, 2005), and related economic costs (see Rittmaster et al., 2006). Forest fires can also produce mental health stress, because of hastened evacuations and displacement (Soskolne et al., 2004). During a May 1995 forest fire, the only road access to Fort McMurray was cut off, causing difficulties for transport of medical emergencies and certain supplies (Soskolne et al., 2004).

Drought is also a source of distress for farming lifestyles, mostly because of associated financial problems (Olson and Schellenberg, 1986; Walker et al., 1986; May, 1990; Ehlers et al., 1993; Deary and McGregor, 1997). Stress in agricultural occupations not only affects the farmers but also cascades into family life (Plunkett et al., 1999).

Flooding

Flooding can set the stage for a population explosion of disease-carrying vectors, such as mosquitoes and rodents. Outbreaks of water-borne disease have been linked to intense precipitation, flooding and run-off from agricultural livestock areas (Millson et al., 1991; Bridgeman et al., 1995; Charron et al., 2003, 2004; Schuster et al., 2005). A case-control study in southern Alberta (Charron et al., 2005) found that each extra day of rain in the preceding 42 days increased the risk of hospitalization for gastrointestinal illness. However, if the number of rain days exceeded the 95th percentile during this time period, the odds of hospitalization decreased, possibly due to dilution or cessation of pathogens. These findings were opposite to those in an Ontario case study (Charron et al., 2005), thereby suggesting that regional differences are important in determining the potential impact of climate change on waterborne diseases.

Slow-rising riverine floods have a low potential for mortality, and the major health effects may be longer term psychological problems (Phifer et al., 1988; Phifer, 1990; Durkin et al., 1993; Ginexi et al., 2000; Tyler and Hoyt, 2000), as well as moulds and mildew and the associated respiratory ailments from extremely wet conditions (Square, 1997; Greenough et al., 2001). Losing a home or witnessing it being destroyed, being evacuated on short notice, or being displaced for an extended period of time all cause great anxiety (Soskolne et al., 2004). Flooding causes economic loss, which in turn creates stress and hardship for those experiencing the loss. Uncertainty about who is expected to pay for the loss is also a source of stress (Soskolne et al., 2004).

Changing Ecosystems and Vector-Borne Diseases

Hantaviruses are transmitted to humans via the inhalation of aerosolized hantavirus from rodent excreta and saliva (Stephen et al., 1994; Gubler et al., 2001), giving rise to hantavirus pulmonary syndrome (HPS) in humans. The deer mouse is most often associated with HPS (Stephen et al., 1994; Glass et al., 2000). Between, 1989 and 2004, there were 44 cases of HPS, all from western Canada, with the majority of cases (27) in Alberta (Public Health Agency of Canada, 2000, 2006). Mortality is 40 to 50% (Public Health Agency of Canada, 2001). Human cases of HPS seem to reflect the yearly and seasonal patterns of high rodent population densities (Mills et al., 1999). Large increases in rodent populations have been linked to mild wet winters, and to above-average rainfall followed by drought and higher-than-average temperatures (Engelthaler et al., 1999; Gubler et al., 2001), climate conditions that are projected to become increasingly common in the Prairies (see Section 2.5).

West Nile virus (WNV) is transmitted from its natural bird reservoirs by mosquitoes (primarily the genus Culex). The climatological conditions that favour the WNV are mild winters, coupled with prolonged drought and heat waves (Epstein, 2001; Huhn et al., 2003). The Culex mosquito can overwinter in the standing water of city sewer systems, and heat tends to speed up the viral development within the mosquito (Epstein, 2001). The Prairies have recorded a disproportionate number of WNV cases, accounting for 91.2% of the 1478 documented cases in Canada in 2003 (Public Health Agency of Canada, 2004a). In 2004 and 2005, the numbers of clinical cases in the Prairies were 36.0% (of the 25 in Canada) and 58.6% (of the 210 in Canada), respectively (Public Health Agency of Canada 2004b, c). Fortunately, the majority of people (80%) infected with WNV are asymptomatic, with severe symptoms (e.g. coma, tremors, convulsions, vision loss) showing up in approximately 1 in 150 people infected (Centers for Disease Control and Prevention, 2005).

Although Lyme disease is expected to be a significant public health threat in eastern Canada, the Prairies will likely remain too dry for this to become a major health concern. Other diseases affected by climate change or resulting ecosystem changes that may become a health threat in the Prairies are western equine encephalitis, rabies, influenza, brucellosis, tuberculosis and plague (Charron et al., 2003). These diseases have either an animal reservoir population, known human cases or a history in the Prairies, and are sensitive to changes in climate (Charron et al., 2003).

Higher Average Temperatures

Increasing temperatures could exacerbate food poisoning because longer, warmer summers are conducive to accelerated growth of bacterial species and to the survival of bacterial species and their carriers (e.g. flies; Bentham and Langford, 2001; Rose et al., 2001; Hall et al., 2002; D'Souza et al., 2004; Kovats et al., 2004; Fleury et al., 2006). Fleury et al. (2006) confirmed cases of food-borne diseases in Alberta, finding a positive association between ambient temperature and disease for all time lags (0 to 6 weeks) and for every degree increase in weekly temperature above the threshold temperature (0 to –10°C). Depending on the pathogen type, the relative risk of infection increased from 1.2 to 6.0%.

Warmer temperatures enhance the production of secondary pollutants, including ground level ozone (Last et al., 1998; Bernard et al., 2001). Although cities on the Prairies have relatively low concentrations of air pollution (Burnett et al., 1998; Duncan et al., 1998), current pollution levels do affect morbidity and mortality (Burnett et al., 1997, 1998). The elderly, those with pre-existing medical conditions, and children are likely to be at higher risk from the negative health impacts resulting from climate change, population growth and increasing pollution concentrations in the major centres (Last et al., 1998). Increased winter temperatures will decrease the number of cold-related deaths. More people generally die in winter than in summer, mainly from infectious diseases (e.g. influenza) or heart attacks (McGeehin and Mirabelli, 2001).

Economic Vulnerability

Economic vulnerability to climate change indirectly affects health and well-being. It often precedes negative health outcomes from extreme weather events. Economic losses, especially ones that individuals cannot afford, are a major source of stress. Economic vulnerability is closely linked to whether individuals can afford insurance, the socioeconomic status of individuals, and the wealth and resources of communities and governments.

Losing property during an extreme event is costly, as not all losses are covered by insurance or government aid programs (Soskolne et al., 2004). The financial stresses associated with disasters have the greatest effect on families with low socioeconomic status and on the elderly with fixed incomes, who are least able to afford insurance and the cost of damages, and are most likely to be living in vulnerable areas. In the future, these groups may be even less able to purchase insurance and afford the costs of adapting to extreme weather events. Drought disaster assistance programs attempt to cover uninsured crop losses; however, these rarely cover the season's initial investment, thereby increasing personal debt. Inability to repay debt tends to lead to increased financial pressures and, in turn, can lead to depression, stress and even suicide (Soskolne et al., 2004).

Certain segments of society are more vulnerable to the health threats described above by virtue of their demographics, community setting and infrastructure, health, and regional, socioeconomic or cultural circumstances (Smit et al., 2001). Vulnerable populations will likely bear a disproportionate burden of the future economic costs and negative health consequences. Table 11 presents a summary of the various vulnerable populations and explains how they are at increased risk from climate sensitive health outcomes.

TABLE 11: Examples of adaptation measures for forest management, as identified by Spittlehouse and Stewart (2003).

Vulnerable population	Characteristics of increased vulnerability	Higher temperatures and heat waves	Drought	Extreme hydrological events	Changing ecosystems
Elderly	More likely to have underlying health conditions (see below) Social isolation and decreased social networks More susceptible to food-borne diseases Fixed incomes 50+ age group at greater risk of developing severe West Nile virus illness	X	X	X	X
Children	Immature systems and rapid growth and development may enhance toxicity and penetration of pollutants, decrease thermoregulatory capacity and increase vulnerability to water and food-borne diseases Exposure per unit body mass is higher than for adults Dependent on adult caregivers Lower coping capacity	X	X	X
People with underlying health conditions	Cardiovascular and respiratory conditions increase risk Medications decrease thermoregulatory capacity and heat tolerance Mental illnesses, such as schizophrenia, alcohol abuse and dementia, are a risk factor for death during heat waves Reduced mobility or a need for regular medical attention makes evacuation more difficult	X	X	X
People of lower socio-economic status (SES)	Associated with poorer health overall Have less control over life's circumstances, especially stressful events, and are less able to better their outcome More likely to be located in higher risk areas Higher heat-related mortality is associated with lower income neighbourhoods Less likely to afford recovery or adaptation measures Homelessness is often associated with underlying mental health conditions (see above)	X	X	X
Aboriginal peoples	More likely to have lower SES (see above) Traditional livelihoods at risk Poorer infrastructure Limited access to medical services	X	X	X	X

There will likely be additional costs to the public health care system as a result of the costs of treatment (e.g. medications or emergency room visits) and/or containment of various diseases, screening, community surveillance, monitoring and intervention.

4.6 ENERGY

Climate change will impact the petroleum industry in the Prairies by affecting exploration and production, processing-refining and transportation, storage and delivery. Key climate variables of concern are increasing temperature, changing precipitation and extreme events (Huang et al., 2005). Of greatest concern is, and will continue to be, water scarcity, as current production of oil, and even some natural gas, relies on significant quantities of water (Bruce, 2006).

Most exploration and drilling programs are currently carried out in northern parts of the Prairies during winter, when frozen soils and wetlands are easily crossed and ice roads provide comparatively inexpensive routes for heavy transport across boreal terrain. Although warmer, shorter winters may make outside work slightly less dangerous from a health and safety perspective, this modest advantage will be countered by increased costs resulting from shortened winter work seasons.

Warming is already causing substantial permafrost degradation in many parts of the north (see Chapter 3; Majorowicz et al., 2005; Pearce, 2005), which will lead to land instability, soil collapse and slope failures. These changes, combined with increased frequency of extreme climate events, will create problems for infrastructure, including building foundations, roads and pipeline systems, resulting in pipeline ruptures and costs to reroute current pipelines to more stable locales (Huang et al., 2005).

The refining sector will experience increased potential for vapourization leaks as a result of longer and hotter summers. Greater cooling capacity will be needed at a time when local and regional water supplies — a key cooling fluid — will be warming beyond historical temperature peaks. These changes could disrupt refinery operations due to safety concerns and environmental and health issues, all with potential to cause economic losses (Huang et al., 2005).

Coal-Fired and Natural Gas–Fired Electricity Generation

Coal-fired electricity generation creates large quantities of waste heat that is dispersed using cooling water from nearby water sources. Degradation in cooling water quality (e.g. from increases in dissolved solids) creates engineering problems for the cooling systems of coal plants because the water must either be treated before use or a scale-removal program must be in place to prevent inappropriate scale build-up (Demadis, 2004).

Declining water quantity in the Prairies region resulting from climate change will reduce the supply of cooling water to power plants during drought periods or in other low-flow periods. When cooling water is in short supply, plants must cut back on operations, resulting in financial losses on a daily basis; and the coolant water that is used may be returned to the source watershed at temperatures high enough to damage aquatic ecosystems. Environmental impacts of coolant water will be exacerbated by temperature increases resulting from changing climate (Jensen, 1998).

Hydroelectric Generation

Approximately 95% of the electricity generated in Manitoba comes from renewable water energy (Manitoba Science, Technology, Energy and Mines, 2007). In Alberta and Saskatchewan, hydroelectric power is a modest but important part of the electrical generating capacity. Forecasts of future capacity for generating hydroelectric power must take into account decreasing average spring and summer flows for the western portion of the Prairies due to glacial ice decline (Demuth and Pietroniro, 2003) and lower overall snow accumulations (Leung and Ghan, 1999; Lapp et al., 2005).

Oil Sands Mines

Oil sands operations in northern Alberta are expanding at a dramatic rate. They currently produce more than 1 million barrels per day of synthetic crude oil, and production is forecast to be 3 million barrels per day by 2020 (Alberta Energy, 2005). Projected investments in oil sands recovery are $125 billion for the period 2006 –2015 (National Energy Board, 2006). Oil sand mining, and oil extraction and refining, are water- and energy-intensive processes. Best current estimates are that the operations that produce synthetic crude oil or upgraded bitumen require 2 to 4.5 barrels of water for each barrel of oil (Griffiths et al., 2006). Assuming similar water/oil ratios in the future, production of more than 3 million barrels per day in 2010 would require 6 to 13.5 million barrels of water per day.

Testimony of witnesses at the Energy and Utilities Board hearings in the fall of 2003 addressed the Environmental Impact Assessments for two proposed oil sands plants. Presentations argued that 1) neither plant could sustain operations during low-flow periods of the Athabasca River without damaging the aquatic ecology, and 2) the effects of climate change on water supplies would reduce low-flow quantities and increase the length of low-flow periods. In a recent analysis of trends in both water demand for oil sand projects and water availability under climate change, Bruce (2006, p. 13 –14) concluded that:

“…even at the lower end of the water withdrawals from oil sands projects, there would have been 10 times during the past 25 years where the minimum flows of the Athabasca River would have been insufficient to avoid short term impacts on ecosystems. For longer term ecosystem impacts, the recommended water restrictions on oil sands project withdrawals, indicate that minimum flows would not have met full development needs in 34 of the past 35 years.”

Oil sands operations are in water-rich regions of the boreal forest. Large engineering works are needed to dewater regions and to store water previously stored in wetlands. Large-scale tailings ponds are also typical of open pit mines. Extreme precipitation events could cause overflows and spillage of contaminated or fresh water in storage. Tailings ponds contain naphthenic acids, a toxic and corrosive pollutant (McMartin et al., 2004) produced in large quantities by oil sands extraction and upgrading processes. These acids are persistent in water, but their occurrence and fate have been minimally studied (Headley and McMartin, 2004). This pollutant could affect up to 25 000 km 2 of oil sands developments, and much more if tailings ponds leak or overflow due to extreme climate events.

Renewable Energy Sources and Climate Change

Little research has been done on the possible impacts of climate change on the renewable energy sector. Renewable energy sources include solar- and wind-generated power, geothermal heat exchange and hydroelectric power. Climate change is not likely to have a substantive effect on solar-generated power unless there is a large change in cloud cover.

Wind-generated power has substantial potential across the Prairies Provinces, as sustained winds are common. Southern Alberta and southwestern Saskatchewan have considerable wind development already, and there are plans for more developments. Changes in sustained wind speeds under climate warming are possible as temperature gradients from the equator to the pole are reduced. One American study (Breslow and Sailor, 2002) has projected a modest decline in winds over the continental United States.

4.7 TOURISM AND RECREATION

A study of the potential impacts of climate change on visitation to national parks in the southern boreal forest (e.g. Prince Albert National Park, SK) suggests that visitation would increase by 6 to 10% in the 2020s, 10 to 36% in the 2050s and 14 to 60% in the 2080s, based on a relationship between temperature and visitor days (Jones and Scott, 2006). The primary impact of climate change was to increase the length of the shoulder seasons (i.e. spring and autumn). In grassland areas, biodiversity is likely to be impacted due to changing habitat and invasive species. Climatic conditions along the southern boundary of the boreal forest will cause a shift in vegetation to more drought-resistant species, especially grasses (Thorpe et al., 2001; Hogg and Bernier, 2005). Loss of stands of trees at some sites and other vegetation changes are unavoidable.

Changes in vegetation will impact wildlife habitat and change species distributions (Gitay et al., 2002). Species of interest may no longer inhabit protected areas, where they have been traditionally viewed or hunted. On the other hand, an increase in forest fire activity under future climate conditions (Flannigan et al., 2005) could provide increased habitat for species, such as deer and moose, that are dependent on early to mid-successional forests. Wildlife species important for viewing and hunting will adjust rapidly to changing environmental conditions. However, a major impact on hunting could be a loss in waterfowl habitat as prairie potholes dry up, resulting in a decline of as much as 22% in duck productivity (Scott, 2006). Communities dependent on these activities could experience reduced tourism revenues (Williamson et al., 2005).

Lower lake and stream levels, particularly in mid- to late summer (see Section 3.1), may reduce opportunities for water-based recreation: swimming, fishing, boating, canoe-tripping and whitewater activities. Early and rapid spring snowmelt may prevent spring water-based activities due to high or dangerous water conditions. Changes in water temperatures and levels will affect fish species distributions (Xenopoulos et al., 2005). Warmer springs would result in earlier departure of ice from lakes, limit the ice fishing season and increase the likelihood of unsafe ice conditions.

In Alberta's mountain parks, climate change has already caused vegetation and associated wildlife species to migrate to higher elevations (Scott et al., 2007), and this will accelerate under future warming. Scott and Jones (2005) and Scott et al. (2007) examined the potential impacts of climate change on visitation patterns in Banff and Waterton Lakes national parks, respectively, utilizing a number of climate change scenarios. They found that climate change could increase visitation to Banff by 3% in the 2020s and 4 to 12% in the 2050s, depending on the scenarios used. For Waterton Lakes, increases associated with changing climate were forecast to be 6 to 10% for the 2020s and 10 to 36% for the 2050s. In both cases, increases were due mainly to increased temperatures. However, Banff's ski industry may be negatively affected by less snowfall. The skiing season could decline by 50 to 57% in the 2020s and 66 to 94% in the 2050s in areas less than 1500 m in elevation, although snowmaking will help reduce these impacts (Scott and Jones, 2005). Higher altitude ski areas would be affected much less. Less snow cover and a shorter season will also affect the timing and amount of opportunities for cross-country skiing, snowshoeing and snowmobiling (Nicholls and Scott, in press).