What is the issue?

The weather affects us all. The economic and human losses from floods, tornadoes, severe winds, snow, and ice storms can be tragic and are often severe. As the population of Canada grows, population concentrations increase along with chances that extreme weather events will affect more people.

Some researchers indicate that an increase in the frequency and intensity of hurricanes, tornadoes, and other extreme weather events has occurred over the last 15–20 years. However, there is not yet enough scientific evidence to show a link between increasing severe weather and a changing climate.

What do we know?

While there is insufficient scientific evidence supporting a link between weather extremes and global warming trends, there is little debate that Canadians have experienced recent changes in weather patterns and a substantial increase in the number and cost of weather-related disasters.

In the Atlantic Ocean, there has been a dramatic increase in the number of hurricanes since 1995. Between 1995 and 2000, 49 hurricanes occurred—the most active six consecutive years of tropical storms on record, following the four quietest years this century. In Canada, where an average of one or two tropical storms each year enter Canadian waters, 1998 and 1999 each saw an average of four tropical storms.

•  Download Weather-related disasters in Canada, 1900-1999 (MS-Excel)  
•  Weather-related disasters in Canada, 1900-1999 (Html)

Few people can remember water levels in the Great Lakes being as low as in the fall of 2000, which marked the 14th consecutive season with above-normal temperatures in Canada. The low levels are due to lower precipitation totals and less runoff from rivers and streams, as well as increasing evaporation losses and greater consumption of water.

Canadian property and casualty insurers are well aware of the havoc caused by weather-related disasters. Ever since the Edmonton tornado in 1987, there has been an increase in both the frequency and severity of multi-million-dollar weather-related disasters. Between 1983 and 1987, such disasters cost Canadians about $500 million. By contrast, between 1993 and 1997, the cost to insurers and taxpayers was more than $1.5 billion. In 1998 alone, the cost of natural disasters more than doubled again to over $4 billion, primarily as the result of the ice storm in eastern Ontario, Quebec, and the Maritime provinces.

• Ice storm 1998: $4.2 billion
• Saguenay flood 1996: $1.2 billion
• Red River flood 1997: $400 million
• Calgary hailstorms 1991: $400 million
• Edmonton tornado 1987: $300 million
• British Columbia blizzard 1996 –1997: $200 million

What additional information do we need?

The most immediate need is a greater understanding of weather patterns and prediction, so that warnings can be issued in time for communities and individuals to avoid disaster from serious storms and severe weather events. Over the medium and longer term, Canadians and their governments need to know what the future holds in terms of the frequency, intensity, and duration of extreme weather events, such as floods, intense rain and snowfall, and severe droughts. The more knowledge we have, the better decisions we can make. These decisions would affect locations and types of infrastructure (our bridges, buildings, and roads, for instance), as well as the design of towns and cities, planning for emergencies, the management of agricultural enterprises and communication systems, and the design of energy and water networks.

What are we doing based on the information we have?

Timely and accurate weather warnings and advisories issued by Environment Canada have helped to reduce the number of casualties and damage from natural disasters. A national lightning network was recently added, and a national Doppler radar network is being installed, aimed at giving meteorologists the data they need to detect and predict severe weather more quickly and more precisely. Research is ongoing to constantly improve our scientific understanding of the systems that influence weather and the methods and tools to better predict environmental hazards. Environment Canada is also investigating new ways to better deliver weather information to all Canadians, including national telephone and Internet weather information and television WeatherAlert messages.

Further information

For more information on severe weather events, please consult the following*:

• Climate Change and Extreme Events: Canada, by David Etkin, in Canada
  Country Study: Climate Impacts and Adaptation (1997):
  www.ec.gc.ca/climate/ccs/pdfs/volume8/vol8ch2.pdf
• Environment Canada climate change web site:
  www.ec.gc.ca/climate/
• Extreme Weather and Climate Change, by David Francis and Henry Hengeveld (1998):
  www.msc-smc.ec.gc.ca/saib/climate/Climatechange/ccd_9801_e.pdf

*Note: Information found on some sites is presented only in the language in which it was written. We apologize for any inconvenience.