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Backgrounder
Climate, Nature, People: Indicators of Canada's Changing Climate

Climate affects just about every aspect of nature and human life. The kinds of plants and animals that inhabit a particular place are determined to a great extent by climate. So is the amount of water in a river or the height of water along a shoreline. Likewise, our health and safety, our comfort and mobility, our food supply, and our access to water all depend in one way or another on climate, as do many other things we need or value. When climate changes, all of these are affected too – sometimes slightly, sometimes considerably, sometimes for the better, and sometimes for the worse.

Canada’s climate has begun to change in a number of ways, and some impacts of those changes are already noticeable. As citizens, we need to be aware of those changes and their consequences for the world around us. That is why the Canadian Council of Ministers of the Environment (CCME) commissioned Climate, Nature, People: Indicators of Canada’s Changing Climate. The objective of the report is not to predict how climate change might unfold in the future but to give Canadians some idea of how a changing climate may already have affected their lives and the environment.

Here are selected highlights from Climate, Nature, People: Indicators of Canada’s Changing Climate:

Climate

• Almost every part of southern Canada, from coast to coast, was warmer at the end of the 20th century than it was at the beginning. Northwestern Canada has also seen strong warming over the past 50 years, but the Northeast has become cooler.


• Most of Canada has become wetter, with increases in precipitation ranging from 5% to 35%.


• Because of increased precipitation, Canada was generally snowier at the end of the 20th century than at the beginning. Over the past 50 years, however, higher spring temperatures have reduced the proportion of precipitation falling as snow in some parts of southern Canada.


• Sea surface temperatures have risen substantially on Canada's west coast, but appear to have changed little on the east coast.

Nature

• Rising sea levels are making many areas along the Atlantic, Pacific and Beaufort Sea coasts more vulnerable to flooding and erosion


• Ice on rivers and lakes in most of Canada is breaking up earlier in the spring. During the past 30-50 years, however, there has been a tendency in much of the country towards earlier freezing dates in the fall.


• Most glaciers in Canada are shrinking.


• The area of the Canadian Arctic that is permanently covered by sea ice has decreased by about a quarter since the late 1960's.


• Hudson Bay is now ice-free a week longer, on average, than it was 30 years ago.


• A shorter ice season has made survival more difficult for polar bears on the western side of Hudson Bay.


• Key stages in plant development, such as budding, leafing, and flowering, are occurring earlier, mainly because of earlier and warmer spring weather.

People

• The traditional knowledge that aboriginal people relied on in the past to live off the land is becoming harder to apply as a result of more variable weather and changes in the timing of seasonal phenomena. A shorter, less reliable ice season has also made winter travel, hunting, and fishing in the North more difficult and dangerous.


• Although recent years have been marked by severe drought on the Prairies, long-term data do not show that droughts are occurring more often.


• Since 1900, data for the Great Lakes suggest periodic changes in water levels but no long-term trend towards lower water levels. Recent low water levels, however, have had important consequences for shipping, hydro electric generation, and wildlife.


• The frost-free season has been getting longer in most parts of Canada because the last spring frosts have been happening earlier.


• Heating needs across most of Canada have decreased during the past century. Many parts of the country have also seen cooling needs rise.


• There is no strong evidence that extreme weather events have become more common in Canada, even though the 1990s witnessed some of the most damaging and costly weather disasters in Canadian history.

Access the full report or order print copies at www.ccme.ca.

Canadian Intergovernmental Conference Secretariat (CICS)

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