Effects of Climate Change: The Big Picture Water Resources

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Effects of Climate Change The Big Picture -
Water Resources

• Linda Mortsch
• Adaptation and Impacts Research Division,
  Environment Canada
• Adapting to climate change business planning,
  risk management, emergency preparedness
  Conference Board of Canada
• Ottawa, Ontario January 22, 2008

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Expected changes in climate

• Increase in temperature (greatest in winter and
  spring)
• SNOW changes to RAIN
• More evapotranspiration
• Increase in annual precipitation for most of
  Canada
• Canadian Prairies decrease
• Changes in seasonal precipitation
• more precipitation in winter

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Water managers will have to deal with new
realities

• Past climate is not a reliable guide for future
  planning
• Changes in distribution, amount, timing and
  quality of water supply
• More extreme conditions
• More complex, controversial water apportionment
  issues

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New flooding risks and potential increase in
damages

• More intense precipitation and winter rain
• flooding in winter and summer?
• Infrastructure must accommodate higher flows
• safety and performance issues
• Re-evaluate floodplain management and emergency
  preparedness
• more structures and people exposed

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Water levels are projected to decrease
Source Lemmen Warren, 2003
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Energy supply affected by changing hydrology

• Increase in electricity demand for space cooling
• Opportunities Northern regions e.g., James Bay,
  Québec
• Problems - Great Lakes, western U.S. Canada
  (Columbia, Colorado Rivers)

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More difficult to meet water quality goals

• Extreme precipitation events
• combined sewer overflows and sediment and
  nutrient input from erosion
• Low flow in streams
• assimilating pollutants from sewage treatment
  plants and industry
• Warmer water temperatures
• taste and odour problems in Municipal water

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Need to initiate proactive planning for
adaptation

• Climate change exacerbates current management
  concerns
• changes in frequency, intensity, extent and/or
  magnitude of existing problems
• Understand current climate sensitivity of your
  activity/ sector/community
• Explore implications of climate change scenarios
  to show risks and vulnerability
• Hedge against potential impacts and manage/plan
  to build resilience