Canada's Emission Trends 2014: chapter 2

Historical Greenhouse Gas Emissions by Sector

Emissions by Activity and Economic Sector

There are several methods to categorize the sources of Greenhouse Gas (GHG) emissions. These include the Intergovernmental Panel on Climate Change (IPCC) sectors as presented in the National Inventory Report (NIR), Environmental Accounts as developed by Statistics Canada and Economic Sectors as presented in this report. For the purposes of analyzing trends and policies, it is useful to allocate emissions to the economic sector from which the emissions originate. As such, this report presents emissions by “economic activity.” This method of categorization is also presented in the NIR and in the Canadian Environmental Sustainability Indicators for comparability purposes.

Historical Emissions

Historical emissions estimates within this report are aligned to the annual NIR, which is submitted to and reviewed by the UNFCCC. This report uses data from the 2014 NIR, which contains emissions estimates to the year 2012 (the most recent available year of historical emissions data). Every year, the estimates are updated to reflect the availability of data as well as improvements and refinements to data sources and methodological techniques. For this reason, the historical emissions reported here will differ slightly from those reported in Canada’s Emissions Trends 2013.

As shown in Table 1, from 1990 to 2005, total emissions grew from 591 Mt to 736 Mt. The majority of this increase occurred in the transportation sector, the oil and gas sector, and the electricity sector. In the transportation sector, changes in subsectors including light-duty and heavy-duty vehicles caused an increase in emissions of 40 Mt when compared with 1990 levels. Increased production and processing of oil and natural gas resulted in an increase in emissions of 58 Mt in the oil and gas sector, and the electricity sector had an increase of 27 Mt over this time period, which is mostly attributable to rising demand.

Canadian GHG emissions were stable between 2010 and 2012. In 2012, emissions were 699 Mt, 37 Mt below 2005 levels, reflecting decreases or stability in emissions in most sectors. The exception is the oil and gas sector, where emissions increased by 14 Mt. Notably, GHG emissions in the electricity sector decreased 35 Mt over the period, primarily the result of Ontario’s coal generation phase-out. Compositional changes within the sectors, energy efficiency improvements, and changes to energy prices have all helped contribute to relatively stable emissions in the other sectors.

Table 1 shows historical emission levels for selected years up to 2012 for each of the major economic sectors that generate emissions. The specific gases included in the table above are: carbon dioxide (CO2), methane (CH4), nitrous oxide emissions (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur-hexafluorides (SF6), which have been converted into CO2 eq with global warming potential values from the second Assessment Report of the IPCC.

Table 1: GHG Emissions by Economic Sector (Mt CO 2 eq) (excluding LULUCF)
Mt CO2 eq 1990 2005 2010 2011 2012
Transportation 128 168 167 166 165
Oil and Gas 101 159 163 164 173
Electricity 94 121 99 92 86
Buildings 70 84 79 85 80
Emissions-intensive and Trade-exposed Industries 95 89 76 80 78
Agriculture 54 68 68 67 69
Waste and Others 48 47 46 47 47
National GHG Total 591 736 699 701 699

Note: Numbers may not sum to the total due to rounding.


In 2012, emissions from transportation (including passenger, freight and off-road emissions) were the second-largest contributor to Canada’s GHG emissions, representing 24% of overall GHGs.

Between 1990 and 2005, emissions in the transportation sector increased by 31%, from 128 Mt in 1990 to 168 Mt in 2005. This was driven by a strong period of economic growth and low oil prices from 1990 to 1999 that influenced the fleet composition and its use (e.g., more light-duty trucks in comparison with cars).

Since 2005, transportation emissions have been relatively stable, representing 165 Mt in 2012. The increasing fuel efficiency of light-duty vehicles has offset the effects of an increased population that puts more vehicles on the road and results in more kilometres (km) driven. For example, between 2005 and 2012, the sales-weighted on-road fuel efficiency for new gasoline cars has improved from 9.2 litres per 100 km to 8.4 litres per 100 km, while the sales-weighted on-road fuel efficiency for new gasoline light trucks has improved from 13.2 litres per 100 km to 11.6 litres per 100 km.

Oil and Gas

Emissions in the oil and gas sector are related to the production, transmission, processing, refining and distribution of oil and gas products. In 2012, the oil and gas economic sector accounted for the largest share of GHG emissions in Canada (25%). Emissions increased by 58 Mt over the 1990 to 2005 time period, primarily as a result of increased production across the sector.

Since 2005, GHG emissions from the oil and gas sector have increased from 159 Mt to 173 Mt in 2012, mainly due to increased oil sands production. Increased emissions from oil sands activity has been partially offset by the gradual depletion of conventional natural gas and oil resources in Canada and a decline in refining emissions. Over the 2011 to 2012 period, however, emissions from conventional light and frontier oil have increased slightly and emissions from in-situ extraction of oil sands increased by 16% due to increased production.


As more than three quarters of the electricity supply in Canada is generated by non-GHG-emitting sources of power, the electricity sector represented 12% of total emissions in 2012, down from 16% in 2005.

Over the 1990 to 2005 period, demand for electricity rose with economic and population growth, and this increase was met with varying sources of power. Emissions from the electricity sector increased over the period, as some provinces expanded their capacity by building fossil fuel-fired power plants (primarily natural gas-fired generation) or by increasing the utilization rate of existing coal to meet growing demand. Between 2005 and 2012, emissions in this sector fell significantly as a number of coal-fired units were closed and more lower and non-emitting sources were brought online.

Emissions-intensive and Trade-exposed Industries

The emissions-intensive and trade-exposed (EITE) sector includes metal and non-metal mining activities, smelting and refining, and the production and processing of industrial goods such as chemicals, fertilizers, aluminum, pulp and paper, iron and steel, and cement.

Emissions from the EITE sector were responsible for 16% of total Canadian emissions in 1990 and fell to 11% in 2012. The decline in recent years (11 Mt from 2005 to 2012) reflects the economic downturn, technological changes such as improved emission control technologies for perfluorocarbons (PFCs) within the aluminum industry, the closure of the adipic acid plant in Ontario and the closure of some pulp and paper facilities. Energy efficiency measures, replacement of raw materials with recycled materials, and use of unconventional fuels such as biomass and waste in production processes were also responsible for the GHG reductions over time.


Emissions in Canada’s commercial and residential buildings increased by 14 Mt between 1990 and 2005, and then dropped 4 Mt by 2012. Still, since 1990 buildings have accounted for about 12% of Canada’s GHG emissions in any given year. Despite a growing population and increased residential and commercial/institutional building stock, energy efficiency and other improvements allowed emissions to drop over the 2005 to 2012 period.


GHG emissions from primary agriculture in Canada consist mainly of methane (CH4) and nitrous oxide (N2O) from livestock and crop production systems as well as emissions from on-farm energy use. Emissions have remained stable over the 2005 to 2012 period, following an increase of 14 Mt from 1990 to 2005. Emissions and removals of carbon from land management and land-use change associated with agricultural lands are accounted for separately in the Land Use, Land-use Change and Forestry sector.

Waste and Others

Emissions from waste management and other non-emissions-intensive industrial sectors such as electric and transport equipment manufacturing remained relatively stable between 1990 and 2005. From 2005 to 2012, GHG emissions from municipal solid waste landfills decreased slightly (by 1 Mt) as provincial government measures aimed at capturing landfill gas and solid waste diversion helped to slow growth from the historical period. Non-emissions-intensive industrial subsectors included in the waste and others sector represent a wide variety of operations and include light manufacturing (e.g., food and beverage and electronics), construction and forestry.

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