The federal government is warning that Canada faces greater frequency and intensity of extreme weather as a result of climate change, as well as increased risks to human health from pollution and the spread of disease-carrying insects.
In a report posted on the department's website, researchers from Natural Resources Canada said it is clear the country's climate is rapidly changing and will continue to do so for the coming decades, even if there are aggressive international efforts to limit emissions of carbon dioxide and other gases that are responsible for the changes.
"Reducing greenhouse gas emissions is necessary to lessen the magnitude and rate of climate change, but additional impacts are unavoidable, even with aggressive global mitigation efforts, due to inertia in the climate system," the report said. "Therefore, we also need to adapt – make adjustments in our activities and decisions in order to reduce risks, moderate harm or take advantage of new opportunities."
The researchers said Canada is in the early stages of preparation for climate-related changes to the environment, and what measures have been taken have yet to be properly evaluated, while "agreed-upon methods to track and measure actions taken to reduce climate change risk and vulnerability do not yet exist."
Chris McCluskey, a spokesman for Natural Resources Minister Greg Rickford, said the government takes the risks seriously and has increased funding for adaptation, with a five-year program announced in 2011.
"Through our support for energy efficiency, climate change adaptation and clean technologies we are helping increase the resilience of Canada's communities and enhancing the competitiveness of our industries," he said in an e-mailed statement.
The NRCan study notes the average temperatures in Canada rose by 1.5 C between 1950 and 2010, adding that "further changes in climate are inevitable."
"On average, warmer temperatures and more rainfall are expected for the country as a whole, with increases in extreme heat and heavy rainfall events, and declines in snow and ice cover."
The government researchers highlighted a range of impacts that can be expected, including increased flooding and wild fires; the spread of insect-borne diseases such as Lyme disease and West Nile virus; increased stress on endangered species and reduction of bird populations, and industrial challenges such as lower levels on the Great Lakes system that will impair shipping. They also predict a longer growing season which could increase food production, especially in northern regions, but will also bring more pests and extreme weather that could reduce crop yields.
Governments and industry are working together to provide increased protection from flooding and to harden critical infrastructure such as power systems from severe weather, said Blair Feltmate, an adaptation expert at the University of Waterloo.
While the United Nations climate panel acknowledged that it is too late to prevent climate change, it nonetheless is advocating for aggressive measures to reduce emissions and limit the impact. UN Secretary-General Ban Ki-moon has invited world leaders to a climate summit in New York in September, with the goal of winning commitments for post-2020 emission reductions, commitments that would form the basis of an international treaty to be concluded in Paris next year.
Prime Minister Stephen Harper recently argued against any climate strategy that would impose direct costs on the economy, though the Natural Resources Canada report makes clear that there will be economic consequences if world leaders cannot agree to the actions needed to moderate the pace of climate change.
"There is a cost to Canada from global emissions and it's in our economic interest to work to get those global emissions down," said David McLaughlin, former executive director of the National Roundtable on the Economy and the Environment, which the government axed in 2012.