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Proactive disclosure Print version   | |  The winds of change: Climate change in Prairie Provinces How are climates changing in the Prairies?
Facing uncertainty Most climate change projections for the Prairies show an increase in temperature under global warming. Some scientists believe that a small increase in precipitation could occur, while others predict a decrease. According to the Canadian Global Climate Model, the southern Prairies could experience serious summer deficiencies in soil moisture by the end of this century. However, not all parts of the Prairies will experience the same effects. While most climate change projections suggest that the semiarid regions of the Prairies can expect an increase in the frequency of drought, some suggest that no major change in drought frequency will occur in southern Alberta.
Temperatures on the rise According to Environment Canada, air temperatures in the Prairie Provinces have warmed historically. The yearly average temperature has warmed by about 1.2°C over about the last 50 years - but winter temperatures have warmed by about 3°C, and summer temperatures have only warmed by about 0.2°C. Since 1948, seven of the top ten warmest years on the Prairies have occurred after 1981. Wetter or drier? Analysis of drought risks for southern Saskatchewan under several climate change scenarios indicates that the frequency of drought and severe drought could increase dramatically. During dry summers, higher temperatures under warmer climates will create increased evaporation and intensify drought conditions. Conversely, there may also be wetter periods when temperatures are cool. Overall, this suggests that soil moisture conditions could become more variable.
Longer growing seasons The climate in the Prairie Provinces has changed over the past 50 years. Generally, the date of the last spring frost has been occurring progressively earlier - about 10 days earlier on average. The length of the growing season on the Prairies has increased, on average, by about 10 to 15 days compared to the 1940s and early 1950s. In the semiarid portions of the Prairies, both the highest and the lowest temperatures in the winter and the spring are warmer than they used to be. Snow-cover fall has decreased, and spring runoff begins earlier now than in past years. The amount of precipitation falling as snow has decreased as temperatures have risen.
References Cutforth, H.W., McConkey, B.G., Woodvine, R.J., Smith, D.G., Jefferson, P.G., and Akinremi, O.O., in press: Climate change in the semiarid prairie of southwestern Saskatchewan: late winter - early spring; Canadian Journal of Plant Science. Hengeveld, H.G., 2000: Projections for Canada's climate future: a discussion of recent simulations with the Canadian Global Climate Model; Climate Change Digest 00-01, Environment Canada, Ottawa, Ontario, 27 p. Williams, G.D.V., Fautley, R.A., Jones, K.H., Stewart, R.B., and Wheaton, E.E., 1988: Estimating effects of climate change on agriculture in Saskatchewan, Canada; in The Impact of Climatic Variations on Agriculture Volume 1: Assessments in Cool Temperate and Cold Regions, (ed.) M.L. Parry, T.R. Carter, and N.J. Konijn; Kluwer Academic Publishers, Boston, Massachusetts, p. 221-382.
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