This page has been archived on the Web

Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact us to request a format other than those available.

Why it matters

Climate change is a global challenge that requires a global solution. At increasing rates over the last 200 years, humans have released greenhouse gases (GHGs) into the atmosphere by burning fossil fuels. These gases prevent heat from escaping, which in turn creates a greenhouse effect and contributes to the warming of the Earth's surface.

There is a general scientific agreement that accumulated GHGs in the atmosphere cause climate change. Scientists strongly agree that the potential environmental impacts of climate change are very significant. Canada is a vast country with a diverse climate, where the impacts of climate change are all the more important and are becoming evident. In the North, for example, the impacts range from reduced Arctic ice cover and increased degradation of permafrost, to a shorter ice road season. In other regions of Canada, impacts include accelerated erosion and more extensive flooding due to sea level rise and more frequent storms in the Atlantic region, stress on fisheries due to rising water temperatures and more severe forest pest infestations in British Columbia, and more frequent droughts, wildfires and severe floods in the Prairies.

As illustrated in Table 2.1, a number of key economic sectors such as transportation, oil and gas, and electricity contribute to Canada's GHG emissions. The future trend, however, for GHG emissions in Canada depends on a number of factors including economic activity, population, development of energy markets and their influence on prices, technological change, consumer behaviour, and government actions.

Table 2.1: Greenhouse gas emissions, by economic sector, Canada, 1990 to 2010
(Mt CO2 equivalent
Greenhouse gases
National GHG total
Oil and gas industry
Emissions-intensive & trade-exposed industries
Waste & others

Source: Canada's Emissions Trends 2012. *Updated to reflect analysis for
the Reduction of Carbon Dioxide Emissions from Coal-fired Generation of Electricity Regulations.

In addition to GHG emissions, the quality of air Canadians breathe is important. Air pollution from sources such as transportation and industrial activities can affect health, the natural environment and the economy.

Even modest increases in air pollution, often seen as smog, can cause small but measurable increases in emergency room visits, hospital admissions and premature deaths. The health effects can have an impact on the economy through reduced work attendance and overall participation in the labour force. According to the Canadian Medical Association, as a result of increased health care costs, reduced worker productivity, reduced quality of life due to illness and loss of life, air pollution costs Canadians and the Canadian economy more than $8 billion per year.

Industrial activity, transportation, electricity and heat production, and the use of products such as paints and solvents are major sources of air pollution, as outlined in Table 2.2.

For more information, please visit CESI.

Table 2.2: Distribution of air pollutant emissions by source, Canada, 2010
(Percent of national emissions)
SourceSulfur oxidesNitrogen oxidesVolatile organic compoundsAmmoniaCarbon monoxideFine particulate matter
Oil and gas industry
Other industries
Transportation (road, rail, air, marine)
Off-road vehicles
Fuel for electricity and heating
Home firewood burning
Paints and solvents
Agriculture (livestock and fertilizer)

Note: Emissions from natural sources (e.g., forest fires), open sources (e.g., road dust), incineration and miscellaneous are not included, except for ammonia (NH3), where agricultural sources have been included in the indicator.

Canadians are also exposed to other toxic air pollutants, including mercury and hexavalent chromium. Mercury is a naturally occurring metal that can be released to the air by human activities, including base metal smelting, waste incineration, and the use of products such as electrical switches and fluorescent lights. Hexavalent chromium is a known carcinogen and can be released to the air a by-products, of fossil fuel combustion or from various industrial processes, including those associated with aerospace and pulp and paper. These pollutants were declared toxic substances under the Canadian Environmental Protection, 1999.

In addition to outdoor air quality, indoor air quality is also important, as a large number of air pollutants are found in Canadian homes, often at much higher levels than are found outdoors, increasing the risk of lung cancer (radon), breathing difficulties, asthma and allergy symptoms, and heart problems.

Date modified: