Canada’s Black Carbon Inventory Report 2025: chapter 2

Black Carbon Emissions and Trends in Canada

This chapter describes the main sources and sectors contributing to black carbon (BC) emissions and their trends since 2013. Emission sources have been grouped according to the following categories:

• Ore and Mineral Industries
• Oil and Gas Industry
• Electric Power Generation (Utilities)
• Manufacturing
• Transportation and Mobile Equipment
• Agriculture
• Commercial/Residential/Institutional

For each of these categories, emissions are further split into sectors.^{Footnote 1}  In keeping with international reporting requirements, Canada’s emissions of black carbon from aircraft at cruising altitude, as well as emissions from international marine navigation, are presented separately from other emission sources in this report and are excluded from Canada’s national total emissions (see Annex 2, section A2.3 for more information).

Transportation and Mobile Equipment is the largest source of black carbon in Canada, accounting for 12 kt (56%), more than half of total emissions in 2023. Of the various sources in this category, off-road diesel engines account for the majority of these emissions, with 7.0 kt (32%) of total emissions in 2023 (Table 2–1). The second-largest source in this category is diesel engines used for on-road transport, which account for 2.2 kt (9.9%) of total emissions.

The Commercial/Residential/Institutional category is the next largest contributor to black carbon emissions in Canada, making up 5.4 kt or 25% of total emissions in 2023. Within this category, Home Firewood Burning is the largest source, accounting for 4.3 kt or 20% of total emissions. Wood is an abundant fuel source in Canada, and it is estimated that 5.6 million tonnes of firewood were burned in Canadian homes in 2023, a decrease of 36% since 2015 (StatCan, n.d.).

Since 2013, black carbon emissions in Canada have decreased overall by 14 kt (40%) in 2023 (Figure 2–1). Trends in black carbon emissions are largely driven by the Transportation and Mobile Equipment category and are consistent with observed trends in emissions of particulate matter less than or equal to 2.5 microns in diameter (PM_2.5) (on which black carbon estimates are based). An overview of each of the source categories and their associated sectors and emissions can be found in sections 2.1 to 2.7. PM_2.5 emissions from combustion for these sources are available online on the Government of Canada Open Data Portal.^{Footnote 2}

When observing long-term emission trends, large-scale events can have a significant impact on a portion of the time series analyzed and should be considered. The years 2020 and 2021 were marked by the COVID-19 pandemic, coinciding with observed decreases in emissions, more notable between 2019 and 2020. Between 2021 and 2023, emissions decreased slightly, but also remained considerably below 2019 pre-pandemic levels (-6.4 kt or -23%) in 2023. Impacts of the pandemic, more pronounced in 2020, are now harder to distinguish in recent years, as black carbon emissions have resumed the gradual downward trend of recent years.

An overview of the methods used to develop the black carbon inventory, improvements applied to this edition of the inventory, sources of uncertainty and possible future refinements are described in Chapter 3. A summary of provincial and territorial estimates of black carbon emissions is provided in section 2.8.

Table 2–1: Black Carbon Emissions in Canada (2023)

Notes:
Totals may not add up due to rounding.
Values in this report have been rounded to up to two significant digits.

Other Emissions Estimated in the Black Carbon Inventory

Figure 2–1: Trends in Canadian Black Carbon Emissions (2013 to 2023)

2.1 Ore and Mineral Industries

Sources in the Ore and Mineral Industries category include primary resource extraction and processing (Table 2–2 and Figure 2–2). For the purpose of this inventory, black carbon emissions were considered for six types of industry (see Table 2–2).

Of all sources in the Ore and Mineral Industries category included in this inventory, the Mining and Rock Quarrying sector accounted for the largest proportion (3.0% or 0.64 kt) of total black carbon emissions and for 71% of this category’s emissions in 2023 (Figure 2–2). Black carbon emissions from Mining and Rock Quarrying increased by 0.045 kt or 7.5% since 2013. Increases in black carbon emissions from the mining sector correspond to increased fuel use over the same period, in addition to increases in combustion emissions reported to the National Pollutant Release Inventory (NPRI). The use of diesel to generate electricity at remote mines in northern areas, combined with the relatively high BC/PM_2.5 fraction for diesel relative to other fuels, is a significant contributor to this sector.

The second-largest source of black carbon emissions in this category is the Iron and Steel Industry, which accounted for 0.20 kt or 0.9% of total black carbon emissions in 2023. Emissions from this sector have increased by 50% since 2013. This is due in part to an increase in iron production and greater variation in the facility-reported data for the latest years.

Table 2–2: Black Carbon Emissions from Ore and Mineral Industries, Selected Years

Notes:
Totals may not add up due to rounding.

Figure 2–2: Trends in Canadian Black Carbon Emissions from Ore and Mineral Industries (2013 to 2023)

2.2 Oil and Gas Industry

The Oil and Gas Industry accounted for 2.5 kt or 12% of all black carbon emitted in 2023. The main sources of black carbon emissions in the Oil and Gas Industry include fuel combustion to power pumps, engines and heaters and natural gas flaring (Table 2–3 and Figure 2–3). Black carbon emissions from fuel combustion are broken down by 12 sectors (see Table below). While flaring occurs in most oil and gas sectors, it is presented separately since it is a significant source of black carbon emissions.

Since 2013, black carbon emissions from the Oil and Gas industry have decreased slightly, by 0.031 kt or 1.2%. Of all Oil and Gas sectors included in this inventory, Flaring and Incineration accounted for the largest proportion (6.0% or 1.3 kt) of total black carbon emissions in 2023 (Figure 2–3). Emissions from this sector decreased by 0.11 kt or 7.7% between 2013 and 2023. Emissions from flaring are directly related to volumes of gas flared in the industry and vary from year to year due to a variety of factors. For example, federal and provincial regulations came into force in 2020 to reduce methane emissions from the oil and gas industry. Since methane is a potent greenhouse gas, flaring is preferred to venting as it reduces emissions of methane and non-methane volatile organic compounds by converting them to carbon dioxide through combustion. It does, however, increase emissions of black carbon as well as carbon monoxide, PM_2.5, and nitrogen oxides. In response to the regulations, the volume of gas flared increased between 2019 and 2023, resulting in a 11% increase in black carbon emissions from flaring over the same period.

The next two largest sources of black carbon emissions in this category are Natural Gas Production and Processing, which accounted for 0.50 kt or 2.3% of total black carbon emissions, and Oil Sands Mining, Extraction and Upgrading, which accounted for 0.32 kt or 1.5% of total black carbon emissions. Since 2013, black carbon emissions from Oil Sands Mining, Extraction and Upgrading and from Oil Sands In-Situ Extraction have increased by a combined total of 0.13 kt (38%). This is consistent with a 69% increase in crude bitumen production from mining operations and an 86% increase in crude bitumen production from in-situ thermal extraction facilities, both of which contribute to increased fuel combustion and flaring activities.

Table 2–3: Black Carbon Emissions from the Oil and Gas Industry, Selected Years

Note:
Totals may not add up due to rounding.

Figure 2–3: Trends in Canadian Black Carbon Emissions from the Oil and Gas Industry (2013 to 2023)

2.3 Electric Power Generation (Utilities)

Electric Power Generation (Utilities) sources include the combustion of coal, diesel, natural gas and other fuels for the purpose of generating electricity. Electric Power Generation (Utilities) accounted for 0.21 kt (1.0%) of all black carbon emissions in 2023 (Table 2–4 and Figure 2–4) with a 1.2% decrease in emissions since 2013. Black carbon emissions from this source category are relatively low. Large facilities using solid fuels are equipped with particulate controls, while boilers and heaters using liquid and gaseous fuels emit limited particulate matter (PM). There is relatively little diesel fuel used in large stationary electricity generation applications.

The largest emitter of black carbon in this category is Diesel electric power generation, which accounted for 0.15 kt (0.7%) of total black carbon emissions in 2023, and 74% of black carbon emissions in this category. The trend is largely influenced by fluctuations in diesel-fired electricity generation. In 2023, black carbon emissions from diesel-fired electric power generation increased by 14% from their 2013 level. Black carbon emissions decreased between 2013 and 2023 for both Coal and Natural Gas electric power generation. The 62% reduction in emissions from coal-fired electricity generation is due to the coal plant closures in Ontario and Alberta and reduced coal consumption in Saskatchewan, while the 35% reduction in emissions from natural gas-fired electricity generation is due to increased generation from renewable sources.

Table 2–4: Black Carbon Emissions from Electric Power Generation (Utilities), Selected Years

Note:
Totals may not add up due to rounding.

Figure 2–4: Trends in Canadian Black Carbon Emissions from Electric Power Generation (Utilities) (2013 to 2023)

2.4 Manufacturing

Manufacturing sources include three sectors (Table 2–5), and accounted for 0.49 kt or 2.3% of total black carbon emissions in 2023. The decreasing trend in this source category between 2013 and 2023 (0.27 kt or 36%) is largely consistent with reduced production in both the Pulp and Paper Industry and Wood Products sectors.

Table 2–5: Black Carbon Emissions from Manufacturing, selected years

Note:
Totals may not add up due to rounding.

2.5 Transportation and Mobile Equipment

Transportation and Mobile Equipment includes black carbon emissions from air, marine, rail, on- and off-road transportation (Table 2–6 and Figure 2–5). Off-Road Transport is a highly diverse sector that includes lawn and garden equipment; recreational vehicles (e.g., pleasure craft and snowmobiles); farm, construction and mining equipment; and portable generators and pumps. Both on-road and off-road diesel engines are subject to emission standards for PM and are equipped with sophisticated emission controls to reduce PM emissions. As more engines within Canada’s vehicle population are equipped with this technology, PM emission rates are expected to decrease which in turn will reduce black carbon emissions.

The Transportation and Mobile Equipment category is the largest source of anthropogenic black carbon from combustion in Canada, accounting for 12 kt (56%) of total emissions in 2023 (Table 2–1). An important source in this category is mobile diesel engines, both on-road and off-road, which emit significant quantities of PM_2.5 and have the highest BC/PM_2.5 ratios of all black carbon sources. As a result, mobile diesel engines account for nearly all emissions from this category, and 42% of total black carbon emissions in 2023. The implementation of effective fuel and engine regulations for on-road and off-road diesel, in addition to reduced on-road diesel fuel consumption, resulted in decreases to on-road and off-road diesel emissions between 2013 and 2023 by 70% (4.9 kt) and 45% (5.7 kt) respectively, contributing to a 54% decrease overall. The remaining black carbon emissions from Transportation and Mobile Equipment come from air, marine, non-diesel on- and off-road transport, and rail transportation, which accounted for 2.9 kt and 14% of the total black carbon emitted in 2023.

Table 2–6: Black Carbon Emissions from Transportation and Mobile Equipment, Selected Years

Note:
Totals may not add up due to rounding.

Other Emissions Estimated in the Black Carbon Inventory

Note:
Refer to Annex 2.3 for more information.

Figure 2–5: Trends in Canadian Black Carbon Emissions from Transportation and Mobile Equipment (2013 to 2023)

2.6 Agriculture

Agriculture sources consist of fuel use for non-mobile equipment (e.g., for drying grain, heating barns) and accounted for 0.026 kt (0.1%) of total black carbon emitted in 2023 (Table 2–7). Since 2013, emissions of black carbon from this source decreased by 0.020 kt or 43%. Throughout the time series, Alberta contributed decreasing amounts of the total Canadian black carbon emissions for this sector; contributing 73% in 2013 and 60% in 2023. On the other hand, Ontario contributed 18% of the total Canadian black carbon emissions for this sector in 2013 and 26% in 2023. The decrease in black carbon emissions between 2013 and 2023 is largely a result of reduced coal consumption in non-mobile equipment in Alberta.

Table 2–7: Black Carbon Emissions from Agriculture, Selected Years

Note:
Totals may not add up due to rounding.

2.7 Commercial/Residential/Institutional Sources

Commercial/Residential/Institutional sources include four sectors (Table 2–8). The majority of emissions from these sources are due to combustion in large, relatively efficient commercial boilers, or in small, less-efficient residential fireplaces and wood stoves. Of all Commercial/Residential/Institutional sources, Home Firewood Burning accounted for the largest proportion (4.3 kt or 20%) of total black carbon emissions in 2023 (Table 2–8). Emissions from Home Firewood Burning are split into three subsectors: Fireplaces, Furnaces and Wood Stoves.

A key determinant of total emissions from Home Firewood Burning is the quantity of wood burned in each type of residential device. The decreasing trend in this sector between 2013 and 2023 (2.5 kt or 37%) can be attributed in part to the reduction in the use of conventional fireplaces and wood stoves and their replacement with fireplace inserts, furnaces and stoves with improved emission controls and combustion efficiencies. It can also be attributed in part to 2023 having a warmer heating season, as indicated by a 15% decrease in heating degree-days.

Excluding Home Firewood Burning, the remainder of this category accounted for 1.1 kt (5.1%) of total black carbon emissions in 2023. Commercial and Institutional Fuel Combustion accounted for 0.95 kt (4.4%) of total emissions, making it the second-largest source of black carbon emissions in this category. New for the current edition of the inventory, black carbon emissions from waste incineration are now included in the Commercial/Residential/Institutional category, accounting for 0.1% of  total emissions in 2023.

Table 2–8: Black Carbon Emissions from Commercial/Residential/Institutional Sources, Selected Years

Note:
Totals may not add up due to rounding.

2.8 Provincial and Territorial Black Carbon Emissions Trends

This section describes black carbon emissions trends by Canadian provinces and territories for 2013 to 2023. Since 2013, black carbon emission trends in Canadian provinces and territories are all consistent with the national trend (Figure 2–1 and Figure 2–6), with decreasing emissions. According to Table 2–9 , the most significant decreases in total emissions between 2013 and 2023 occurred in Ontario, Alberta and Quebec (all 2.8 kt, and 41%, 36% and 38%, respectively). By percentage, the decrease is most notable for New Brunswick (68%).

Table 2–9: Black Carbon Emissions from Canadian Provinces and Territories, Selected Years

Note:
Totals may not add up due to rounding.

Figure 2–6: Trends in Black Carbon Emissions from Canadian Provinces and Territories

The full-time series of national, provincial, and territorial black carbon emissions from 2013 to 2023 are available online on the Government of Canada Open Data Portal.^{Footnote 3} 

References, Chapter 2, Black Carbon Emissions and Trends in Canada

[StatCan] Statistics Canada. ([n.d.] No date). Households and the Environment Survey.