Agricultural Greenhouse Gas Indicator

The Agricultural Greenhouse Gas (GHG) Budget Indicator tracks the greenhouse gas emissions – carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) – associated with Canadian agricultural activities from 1981 to 2016, and reports them in terms of carbon dioxide equivalents (CO2e).

The indicator does not attempt to capture carbon dioxide emissions from fossil fuel consumption by farm machinery, as these emissions are typically reported by the manufacturing and transportation sectors.

Overall state and trend

In 2016, the net GHG emissions (emissions minus absorption by soils) from Canadian agricultural activities, excluding fossil fuel use, amounted to 50 million tonnes of CO2 equivalents (Mt CO2e), which is equal to about 7% of Canada's overall GHG emissions. Total agricultural GHG emissions (not factoring in carbon sequestration by agricultural soils) comes to 9% of Canada's total emissions. You can view these statistics in Environment and Climate Change Canada's National Inventory Report 1990-2018: Greenhouse Gas Sources and Sinks in Canada - Executive Summary.

Use the interactive map below to zoom in and explore different regions.  Note that all the Prairie Provinces show relatively low emissions, despite the agricultural intensity of the region. This is attributed to the uptake of beneficial management practices (BMPs) that promote the sequestration (absorption and storage) of carbon in soils, such as conversion from annual crops to perennial cover, reduced soil disturbance through no- or minimum-tillage, and the shift away from summerfallow – a practice of leaving fields bare.

Since 1981, net national agricultural GHG emissions are unchanged.

Interestingly, while net GHG emissions are unchanged since 1981, carbon dioxide equivalent gases have not all followed a similar trend. In the same period, nitrous oxide has increased by 43% and methane has increased by 7%. This confirms that the stability in net agricultural GHG emissions is primarily due to the change in carbon dioxide emissions from agricultural soils.

Figure 1: Net GHG emissions (kilograms of CO2 equivalents per hectare), 2016
< 750 kg CO2e/ha 750 to 1500 kg CO2e/ha 1500 to 2250 kg CO2e/ha 2250 to 3000 kg CO2e/ha ≥ 3000 kg CO2e/ha

Use the interactive map in Figure 2 to explore the change in net agricultural GHG emissions between 1981 and 2016. It is apparent that the reduction (that is, negative values) is most significant in the Canadian Prairies.

Figure 2: Change in net agricultural GHG emissions (kilograms of CO2 equivalents per hectare), 1981 to 2016
< -450 kg CO2e/ha -450 to -150 kg CO2e/ha -150 to 150 kg CO2e/ha 150 to 450 kg CO2e/ha > 450 kg CO2e/ha

Greenhouse gas performance index

The state and trend of the Greenhouse Gas Indicator can also be seen in the performance index below.

Figure 3: Agricultural Greenhouse Gas Index

Description - Figure 3
Year Index Value
1981 79
1986 79
1991 80
1996 77
2001 78
2006 78
2011 77
2016 74

In 2016, the state of the environment, as it relates to GHG emissions resulting from farming activities in Canada, was in the "Good" category. The index illustrates a slight declining trend since 1981, with emissions caused by increased production being largely countered by improvements in production efficiency, the recent decline in beef production and by enhanced carbon storage in soils.

About the performance indices

Specific trends

This section is not an exhaustive list and highlights a few other trends of interest. In some cases, these are occurring in certain regions and in others they are affecting certain sectors, such as the beef or dairy industries.

Trend 1 – Prairie farmland, significant carbon dioxide sink

The primary reason for stable net agricultural GHG emissions in Canada is due to the change in carbon dioxide emissions from agricultural soils, which went from being a minor source (emitting CO2) of about 1.2 Mt CO2e in 1981 to a sink (indicating absorption of carbon) of about -11.2 Mt CO2e in 2016. Agricultural soils, particularly in the Prairie Provinces of Canada, are now a significant sink for carbon dioxide. Figure 4 demonstrates how this change in status from source to sink in the Prairies (Alberta, Saskatchewan and Manitoba) has changed the trend in net emissions, despite the increases in nitrous oxide, carbon dioxide and methane emissions.

Figure 4: Agricultural GHG emissions, showing methane (CH4), nitrous oxide (N2O), carbon dioxide (CO2) in fertilizers, and carbon dioxide (CO2), as well as total net emissions (reported in CO2e) in the Canadian Prairies (Mt CO2 equivalents), 1981 to 2016

Description - Figure 4
Greenhouse Gas (in Mts carbon dioxide equivalents (CO2e) 1981 1986 1991 1996 2001 2006 2011 2016
Nitrous Oxide (N2O) 10.74 12.24 12.21 15.18 21.50 15.13 15.89 19.01
Methane (CH4) 13.70 12.51 14.54 18.53 20.79 22.33 18.01 17.91
Carbon dioxide in fertilizers (CO2) 0.57 0.57 0.54 0.83 0.86 1.00 1.45 1.95
Soil carbon (Soil CO2) −0.42 −1.05 −2.87 −7.66 −14.18 −19.22 −19.15 −15.13
Net total (All greenhouse gases combined) 24.58 24.27 24.43 26.88 21.97 19.23 16.20 23.74

Reasons for trend 1

This reduction is primarily due to the widespread adoption of BMPs, such as the reduction in tillage intensity, the reduction in summerfallow – a practice of leaving fields bare – and the conversion of annual to perennial cropping systems. These practices improve soil health by encouraging the build-up of soil organic carbon.

Trend 2 – Nitrous oxide increase attributed to nitrogen fertilizer increase

The 43% increase in national agricultural nitrous oxide emissions is primarily due to the growth of nitrogen fertilizer application. You can see this trend in Figure 5.

Figure 5: Nitrogen fertilizer consumption (millions of tonnes), 1981 to 2016
Description - Figure 5
Figure 5 – Nitrogen fertilizer consumption in millions of tonnes, 1981 to 2011
Region 1981 1986 1991 1996 2001 2006 2011 2016
Eastern Canada 0.29 0.32 0.29 0.29 0.30 0.29 0.35 0.41
Western Canada 0.65 0.90 0.87 1.29 1.30 1.25 1.66 2.15
Canada 0.94 1.22 1.16 1.58 1.60 1.54 2.01 2.56

Reasons for trend 2

In 1981, national consumption was about 0.94 million tonnes of nitrogen, which more than doubled to 2.5 million tonnes in 2016. This increase has not been evenly distributed across the country; consumption in Western Canada has increased by more than 200%, whereas consumption in Eastern Canada has only increased by 42%. The dramatic increase in the use of nitrogen fertilizer has helped to set repeated crop production records in Canada, but as a consequence has also increased nitrous oxide emissions.

Trend 3 – Declining animal populations and methane emissions

Agricultural methane emissions in Canada increased by 7% between 1981 and 2016, but decreased substantially between 2006 and 2011 (see Figure 6).

Figure 6: Growth and decline in animal production
Description - Figure 6
Region 1981 1986 1991 1996 2001 2006 2011 2016
Beef Cattle 10.99 9.88 10.75 13.00 13.43 14.32 11.89 11.13
Dairy Cows 1.77 1.50 1.32 1.23 1.08 1.01 0.96 0.94
Swine 9.99 9.92 10.46 11.49 14.11 15.01 12.63 13.87

Reasons for trend 3

The majority (88%) of agricultural methane emissions comes from beef and dairy cattle.

Dairy cattle

Between 1981 and 2016, the dairy cow population in Canada steadily declined from about 1.8 to 0.9 million head. This reduction was made without affecting total milk production in Canada thanks to productivity gains in milk production per cow.

Beef cattle

The beef cattle population increased between 1986 and 2006, before significantly decreasing between 2006 and 2011. There are a variety of reasons for this decline, including:

  • holdover effects from the bovine spongiform encephalopathy (BSE) crisis in 2003–2004,
  • a high Canadian dollar that has made exports to the USA more expensive, and
  • country-of-origin labelling that may discourage consumers in other nations from consuming Canadian beef.

These and other factors have combined to create a challenging economic environment for Canadian cattle producers. This has resulted in a reduction in the beef herd of about 3 million head, equaling a 22% decline since 2006.

Other livestock

While they have increased by 39% since 1981, the number of swine has also declined since 2006. Swine do not produce as much methane as cattle through enteric fermentation. However, since their manure is largely stored in liquid manure management systems, swine manure is a contributing factor to overall methane emissions.

Trend 4 - Eastern Canada farming changes result in increased net GHG emissions

Between 1981 and 2016, Eastern Canada, large areas of southwestern Ontario, the St. Lawrence River Valley, and the St. John River Valley all experienced a net increase in agricultural GHG emissions.

Using the interactive maps in Figure 7, to see the net increase in GHG emissions over last 35 years.

Figure 7: Net agricultural GHG emissions in Eastern Canada (kilograms of CO2 equivalents per hectare), 1981 and 2016
< 750 kg CO2e/ha 750 to 1500 kg CO2e/ha 1500 to 2250 kg CO2e/ha 2250 to 3000 kg CO2e/ha ≥ 3000 kg CO2e/ha

Reasons for trend 4

Dairy herds in these regions have declined, prompting the conversion of perennial forages to annual crops that has resulted in increased soil carbon dioxide emissions. There has also been an increase in nitrogen-demanding crops, such as corn.

Why this indicator matters

Greenhouse gas emissions have been conclusively linked to climate change, and continued emissions may worsen this problem for future generations.

Agriculture has the potential to mitigate by:

  1. Implementing BMPs that either reduce emissions or encourage the capture and storage of carbon in agricultural soils, and
  2. Reducing the intensity of emissions on a per-unit production basis, whereby technological and management solutions are used to lower the amount of emissions it takes to produce a unit of product, such as meat or milk.

Beneficial management practices

In the Prairies especially, producers can increase their land's carbon storage capacity by reducing summerfallow and tillage intensity and by converting annual crops to perennial cropping systems. Other innovations, such as dietary management to lower methane emissions or manure management to reduce nitrous oxide emissions, are encouraged. Canada is one of the founding members of the Global Research Alliance (GRA) on Agricultural Greenhouse Gases, an international network of more than 30 member-countries, devoted to collaboration in agricultural research on greenhouse gas mitigation and BMPs for farmers in Canada and around the world.

Reducing emissions intensity

Due to the need to produce an increasing amount of food to satisfy growing Canadian and global demand, combined with the limitations of existing agricultural GHG mitigation measures, it is important to acknowledge that reducing net Canadian agricultural GHG emissions in the future is likely to be a significant challenge. Therefore, a more realistic expectation of the agricultural sector may be to achieve declining intensity of emissions for a given product over time. For this reason, AAFC is in the process of developing an Emission Intensity Metric which represents the combined GHG emissions associated with the growth, transportation and processing of one unit of a given product, for instance a tonne of grain or a kilogram of beef.

Additionally, AAFC has developed Holos, a model and software program that estimates GHG emissions based on information entered for individual farms.

Carbon Dioxide Equivalent

Carbon dioxide equivalent (CO2e) is a measure for describing how much global warming a given type and amount of GHG may cause, using the functionally equivalent amount or concentration of carbon dioxide as the reference. A CO2e is calculated by multiplying the amount of gas by its associated global warming potential. The global warming potential accounts for the unique ability of each gas to absorb radiation and for its residence time in the atmosphere.

The global warming potentials below are based on the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, as these are the calculations used in determining the GHG indicator findings for 2016, reported above.

Global warming potentials on the Intergovernmental Panel on Climate Change
Greenhouse Gas Global Warming Potential
Carbon dioxide 1
Methane 25
Nitrous oxide 298

This means that 1 kilogram of methane has 25 times the impact of carbon dioxide, and 1 kilogram of nitrous oxide has 298 times the impact of carbon dioxide on global warming.

The global warming potential values have since been revised and reported in the Sixth Assessment report. Recalculating the indicator with these values will result in a change in the magnitude of the emissions, but will not affect the trend in the emissions. The Environment and Climate Change Canada website has more information on global warming potentials.

About the performance indices

The agri-environmental performance index shows environmental performance state and trends over time, based on weighting the percentage of agricultural land in each indicator class, such that the index ranges from 0 (all land in the most undesirable category) to 100 (all land in the most desirable category). An index value that is increasing over time suggests improving environmental performance, while a decreasing index value suggests deteriorating environmental performance over time.

Related indicators

Additional resources and downloads