Climate change is a global problem that will affect the Saskatchewan River Sub-basin (SSRSB). The hydrological effects of climate change should be considered within the context of natural variability. There is considerable climatic and hydrological variability in the basin, both within years and between years, and basin residents and aquatic ecosystems have adapted to this variability. Water management authorities take this into account in developing programs and projects. Adaptation to the effects of climate change has to be considered in addition to adaptation to natural variability.
Recent climate change scenarios for 2050 for the mountain headwaters of the South Saskatchewan River indicate increases in annual mean temperature of 2.0°C and of 9.5 percent in total precipitation. Winters are projected to be wetter and warmer; springs, wetter and somewhat warmer; summers drier and much warmer; and autumns wetter and warmer. By 2080, equivalent annual figures indicate a temperature increase of 3.8 degrees and a precipitation increase of 15.2 percent. Scenarios for the plains portion of the basin tend to show similar temperature increases, but both increases and decreases in annual precipitation. Trend analysis of temperature and precipitation from the recent past tend to show increased temperatures and no consistent trend in precipitation.
A recent review of trends in temperature and precipitation that included the plains portion of the basin indicated that from 1951 to 2004 average daily maximum temperatures increased by about one-fifth of a Celsius degree each decade, and that average daily minimum temperatures increased somewhat more than this. Over the same period, annual snowfall amounts declined throughout the basin, while annual rainfall increased. In Saskatchewan, there was an overall increase in annual precipitation, while Alberta and Manitoba showed annual decreases.
Read more… about the International Adaptations to Climate Change (IACC) report on climate change in the South Saskatchewan River Basin.
SEAWA Watershed Report on Climate Trends and Projections by Dr. Dave Sauchyn, Prairie Adaptation Research Collaborative, University of Regina
These risks are largely due to increasing shifts between drought and periods of wetness on a year to year basis, as well as from social conditions in the communities that affect their ability to adapt to these changes. Vulnerability assessments conducted in several of the basin’s rural communities revealed that they are sensitive to a variety of climate events that could have negative impacts on their livelihoods. This vulnerability is compounded by sensitivities to global market changes and shifts in policy. Some communities have developed strategies to deal with these stresses, but the existing adaptive capacity and the degrees of exposure and sensitivity experienced in the region have been shaped considerably by the strengths and weaknesses of governance networks. Climate change scenarios for the SSRSB predict increases in temperatures and precipitation.
Although the overall change in temperature would create a longer growing season, cold winters that kill off many pests and diseases and store water as snow would be lost. As the climate warms, most of the extra precipitation is expected in winter and spring and increasingly in the form of rain. While a shift to warmer, wetter winters and drier summers is almost certain, most of the risk from climate change will be related to an increase in the year- to- year variability, alternating between prolonged and frequent periods of drought and occasionally extreme wet conditions.
The existing adaptive capacity of communities and governance networks has several challenges that need attention before they can deal with these future climatic conditions. More robust, integrated, and anticipatory approaches are needed to reduce climate risks and maximize opportunities.