Nitrogen Oxide Emissions

In 2011, nitrogen oxide (NOx) emissions were 1944 kilotonnes (kt), a decrease of 117 kt (6%) from 2010 emission levels.

The level of NOx emissions in 2011 was 557 kt (22%) lower than in 1990. The decline in NOx emissions is attributable to two factors: a reduction in emissions from transportation, given the progressive introduction of cleaner technology and fuels for vehicles; and a reduction in emissions from electricity generation as a result of regulation and domestic and international agreements.

Nitrogen oxide emissions, Canada, 1990 to 2011

Nitrogen oxide emissions, Canada, 1990 to 2011

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How this indicator was calculated

Note: Emissions from natural sources (e.g., forest fires) and open sources (e.g., prescribed burning) are not included in the indicator.
Source: Environment Canada (2013) National Pollutant Release Inventory: Air Pollutant Emissions Summaries and Trends.

Sources of nitrogen oxide emissions

Transportation (road, rail, air and marine) contributed the most to Canada’s NOx emissions, representing 33% (644 kt). The oil and gas industry emitted the next-largest proportions of national NOx emissions, representing 23% (450 kt), followed by off-road vehicles with 21% (411 kt).

Nitrogen oxide emissions by source, Canada, 2011

Nitrogen oxide emissions by source, Canada, 2011

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How this indicator was calculated

Note: Emissions from natural sources (e.g., forest fires) and open sources (e.g., prescribed burning) are not included in the indicator.
Source: Environment Canada (2013) National Pollutant Release Inventory: Air Pollutant Emissions Summaries and Trends.

Nitrogen oxide emissions by province and territory

Alberta was the province with the highest proportion of NOx emissions, with 38% (741 kt) of national emissions (national emissions = 1944 kt). The oil and gas industry emitted the largest amount of NOx for this province. Ontario contributed the second-largest proportion of NOx, with 18% (353 kt) of national emissions. British Columbia ranked third, with 12% (241 kt) of national emissions. The oil and gas industry was an important source of NOx in British Columbia. In both Ontario and Quebec, transportation (e.g., cars, trucks, airplanes) and off-road vehicles were the most important sources of NOx emissions.

Nitrogen oxide emissions by province and territory, Canada, 2011

Nitrogen oxide emissions by province and territory, Canada, 2011

View data for this chart
How this indicator was calculated

Note: Emissions from natural sources (e.g., forest fires) and open sources (e.g., prescribed burning) are not included in the indicator.
Source: Environment Canada (2013) National Pollutant Release Inventory: Air Pollutant Emissions Summaries and Trends.

Nitrogen oxide emissions from industrial facilities

Environment Canada’s National Pollutant Release Inventory (NPRI) provides detailed information on air pollutant emissions from industrial facilities. The Canadian Environmental Sustainability Indicators (CESI) program provides access to this information through an online interactive map.

With the CESI interactive map, you can drill down to local areas and obtain details on NOx emissions specific to reporting industrial facilities.

Source: Environment Canada (2013) National Pollutant Release Inventory: Facility Reported Data.

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