**4. Results**

*Climate Change and Agriculture*

**Total cropland and pastureland**

*Regional characteristics of agricultural production in Canada, 2016.*

**Cropland including summer fallow**

**Provinces/ region**

**3. Study methods**

*Source: [10].*

**Table 1.**

In order to organize the review of literature, a conceptual framework of direct and indirect changes hypothesized to climate change was developed (**Figure 3**). A change in the climate would first alter various climate attributes. These may include change in average temperature, change in amount of distribution of

**Total area in 1000 ha Percent of Canada**

**Total cropland and pastureland**

**Cropland including summer fallow**

**Tame and native pastureland**

**Tame and native pastureland**

Manitoba 6450 4707 1743 11.1 12.2 9.0 Saskatchewan 23,470 16,963 6507 40.4 43.8 33.6 Alberta 19,097 10,484 8613 32.9 27.1 44.5 Prairie Region 49,017 32,154 16,863 84.4 83.1 87.2 Canada 58,027 38,342 19,342 100.0 100.0 100.0

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**Figure 3.**

*Conceptual framework for estimating impacts of climate change on society.*

### **4.1 Impacts on climate attributes**

Climate change would alter several climate-related attributes that might affect the Prairie Region. These may include [11] (1) change in the temperature, (2) change in the level of precipitation and its form (more precipitation occurring as rain than snow), (3) inter-year variability in precipitation, and (4) change in the frequency of extreme events. In addition, an indirect economic effect on the region could be through sea level rise affecting agricultural production in other countries, affecting their food self-sufficiency.

Although global warming would affect all parts of the world, higher impacts are predicted for the northern hemisphere (which includes the Prairie Region). This region is expected to become warmer during the fall and winter seasons. In the agricultural belt, increases of 2–4°C will be experienced during the growing season [8]. During the September to November period, an increase of 2–3°C will be more common all over southern agricultural belt in Canada by 2041–2070. Increased temperatures would result in an increase in the duration of the growing season for crops and early seeding dates. Precipitation in the agricultural region is not projected to increase much but its variability is expected to increase. By the 2080s, projected precipitation increases may range from 0 to 10% in the far south, which through enhanced evapotranspiration will result in a moisture deficit during the growing season [12]. Associated with higher temperatures, some of the precipitation in the region would come as rain rather than snow. Depending on the saturation status of the soils, some of the precipitation would result in runoff and may create reduced moisture available for the crops. In addition, runoff from agricultural lands could create environmental problems such as eutrophication of water bodies.

Studies [13–16] have shown greater drought frequency and severity in the region mainly due to increasing temperatures. In the future, there would be a higher persistence of multiyear droughts in central and southern portions of Canadian Prairies. Multiyear severe droughts could have an effect on soil moisture and may eventually make some parts of the region not suitable for agriculture. More recently, flooding has also been a major occurrence. This creates problems for farmers not only through soil erosion but also through late seeding or totally no seeding in some areas. In Manitoba, for example, there is evidence to suggest that recent agricultural losses from flooding increased by over 300% since the historical period (1966–2015) [15].

## **4.2 Biophysical impact of climate change attributes**

### *4.2.1 Impact on water resources*

Water resources in the Prairie Region would be affected through a culmination of changes in key variables governing the hydrological cycle: temperature, evapotranspiration, precipitation, and snow and ice. Since water in most prairie rivers is provided, in part, by melting of glaciers located in the Rocky Mountains (supplemented with seasonal rainfall), higher temperature coupled with evapotranspiration will play an important effect on the water cycle. According to [17], studies based on hydrological models suggest that annual streamflow of the South Saskatchewan River may range from an 8% increase to a 22% decrease, with an 8.5% decrease being an average prediction. In addition, this study suggested that there is not a dramatic drying of the prairies to be anticipated under climate change and that in some cases streamflow will increase for certain climate scenarios and under moderate degrees of climate change.

Another factor that may affect water resources is the form of precipitation. It is expected that due to warmer winters, much of the current winter precipitation, which now falls as snow, could be in the form of rainfall. This has implication for soil moisture for crop and thus for crop growth. Winter warming will reduce snow accumulations in alpine areas and across the prairies. This will cause a decline in annual stream flow and a notable shift in stream flow timing to earlier in the year, resulting in lower late season water supplies. Continued glacier retreat will exacerbate water shortages already apparent in many areas of Alberta and Saskatchewan during drought years. Lower stream flow would have an impact on the output of hydroelectric plants, as well on the capacity of the irrigation reservoirs to provide water to producers.

Groundwater is the source of potable water for about 30% of Manitoba residents, 22% of Albertans, and 43% of Saskatchewan's population [18]. Future groundwater supplies will be affected in a similar manner as changes in surface water flows and frequency of extreme events. Increased rainfall in early spring and late fall will enhance recharge if soil water levels are high; otherwise, water will be retained in the soil, benefiting ecosystem and crop productivity. Drier soils due to higher rates of evapotranspiration result in decreased recharge, which would lead to a slow but steady decline in the water table in many regions.

Climate change may also have an impact on prairie wetlands. Many of these may be reduced in size or even totally dry up, which may have some impact on groundwater quality as well as recharge capacity.

Some studies, such as [19], have reported that the excess heat caused by climate change may influence the effectiveness of inputs for crops; for example, fertilizer productivity may be reduced. This may lead to reduced fertilizer use, which may be good news for water quality damages, such as nitrates in groundwater, eutrophication, among others, but would be bad news for crop yields.

#### *4.2.2 Effect of climate change on soil moisture*

Under climate change, soils are projected to be slightly moister and warmer in winter, but large increases in soil temperature and large decreases in soil water content are projected during the growing season. During the warmer summer conditions, the level of evapotranspiration will increase along with demand from plants. Both of these can result in a drought stress, particularly when soil moisture level is low [20]. Depending on the frequency and intensity of droughts, soil moisture is

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in **Table 2**.

*Resiliency of Prairie Agriculture to Climate Change DOI: http://dx.doi.org/10.5772/intechopen.87098*

expected to decrease and the semiarid areas of the southwestern Saskatchewan and

Extreme dry condition over a prolonged period would have other environmental effects. In fact, the implication of more frequent and widespread droughts is that they place a larger area at risk of desertification more often unless counteracting management strategies are enacted [21]. Development of the sand dunes in southwestern Saskatchewan has been suggested to be an effect of prolonged droughts in the region (see more details in [22]). This would result in a loss of agricultural land

Due to enhanced evapotranspiration, driven by higher temperatures, many regions will experience a moisture deficit despite higher (but variable) amounts of precipitation. Water stress during critical times for plants (e.g., flowering) is especially harmful and would affect plant growth and productivity. Yield responses are sensitive to climatic change and location and tend to reduce the beneficial effects stemming from elevated carbon dioxide (CO2) levels [23]. Details of changes in yields of selected crops in Canada (applicable to the Prairie Region) are presented

Estimates of future yields under climate change have been variable depending on the climate model used, location, and global warming levels. Another uncertainty is created by the positive effect of higher level of CO2 in the future. A study by [23] has reported an increase in the yields of canola and wheat with increase in global warming, while maize (corn) yield was simulated to increase or slightly decrease depending on the characteristics of the currently grown cultivar and differences among the crop models. The same study also indicated that future warming accompanied by increased CO2 concentration would remain beneficial to crop yields at the

Agriculture in the Prairie Region could benefit from warmer and longer growing seasons and a warmer winter. Climate change may also bring opportunities, which could increase productivity and allow cultivation of new and potentially more profitable crops and tree species. A study [27] has indicated that under the projected changes in climate, area allocated to wheat will continue to decrease into the future by 2.7–4.6% in various soil zones, while the area left to summer fallow is projected to increase. The choice of wheat is preferred over pulses, feed, and forages, while the choice of specialty oilseeds (flaxseed, mustard seed, and canary seed) is projected to become preferred over wheat in the future. Change in crop mix has been suggested [28], but it still will be dominated by wheat, barley, and canola. Producers under the changed climate may also introduce some new crops, such as: Pulse crops: Pulse area is likely to increase in the drier, more arid growing

Soybeans: The transition to larger soybean area in the prairies is already underway with former marginal areas in southern Manitoba and Saskatchewan now

Corn: The movement of corn is also underway to parts of southern Manitoba and southern Alberta, but the transition is expected to take a longer time than

southeastern Alberta (an area known as Palliser Triangle) will increase.

*4.2.3 Other environmental effects related to climate change*

for meeting growing demands for humans and animals.

**4.3 Direct impacts of climate change on agriculture**

*4.3.1 Biophysical impacts on crop production*

global warming level of 2.0°C for Canada.

environments that are expected in 2050.

growing the crop in a regular rotation.

*Climate Change and Agriculture*

*4.2.1 Impact on water resources*

under moderate degrees of climate change.

water to producers.

**4.2 Biophysical impact of climate change attributes**

Water resources in the Prairie Region would be affected through a culmination of changes in key variables governing the hydrological cycle: temperature, evapotranspiration, precipitation, and snow and ice. Since water in most prairie rivers is provided, in part, by melting of glaciers located in the Rocky Mountains (supplemented with seasonal rainfall), higher temperature coupled with evapotranspiration will play an important effect on the water cycle. According to [17], studies based on hydrological models suggest that annual streamflow of the South Saskatchewan River may range from an 8% increase to a 22% decrease, with an 8.5% decrease being an average prediction. In addition, this study suggested that there is not a dramatic drying of the prairies to be anticipated under climate change and that in some cases streamflow will increase for certain climate scenarios and

Another factor that may affect water resources is the form of precipitation. It is expected that due to warmer winters, much of the current winter precipitation, which now falls as snow, could be in the form of rainfall. This has implication for soil moisture for crop and thus for crop growth. Winter warming will reduce snow accumulations in alpine areas and across the prairies. This will cause a decline in annual stream flow and a notable shift in stream flow timing to earlier in the year, resulting in lower late season water supplies. Continued glacier retreat will exacerbate water shortages already apparent in many areas of Alberta and Saskatchewan during drought years. Lower stream flow would have an impact on the output of hydroelectric plants, as well on the capacity of the irrigation reservoirs to provide

Groundwater is the source of potable water for about 30% of Manitoba residents, 22% of Albertans, and 43% of Saskatchewan's population [18]. Future groundwater supplies will be affected in a similar manner as changes in surface water flows and frequency of extreme events. Increased rainfall in early spring and late fall will enhance recharge if soil water levels are high; otherwise, water will be retained in the soil, benefiting ecosystem and crop productivity. Drier soils due to higher rates of evapotranspiration result in decreased recharge, which would lead to

Climate change may also have an impact on prairie wetlands. Many of these may be reduced in size or even totally dry up, which may have some impact on ground-

Some studies, such as [19], have reported that the excess heat caused by climate change may influence the effectiveness of inputs for crops; for example, fertilizer productivity may be reduced. This may lead to reduced fertilizer use, which may be good news for water quality damages, such as nitrates in groundwater, eutrophica-

Under climate change, soils are projected to be slightly moister and warmer in winter, but large increases in soil temperature and large decreases in soil water content are projected during the growing season. During the warmer summer conditions, the level of evapotranspiration will increase along with demand from plants. Both of these can result in a drought stress, particularly when soil moisture level is low [20]. Depending on the frequency and intensity of droughts, soil moisture is

a slow but steady decline in the water table in many regions.

tion, among others, but would be bad news for crop yields.

water quality as well as recharge capacity.

*4.2.2 Effect of climate change on soil moisture*

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expected to decrease and the semiarid areas of the southwestern Saskatchewan and southeastern Alberta (an area known as Palliser Triangle) will increase.
