Canada’s agriculture sector’s net greenhouse gas emissions (GGEs) have remained relatively stable since 1990 while its CO2 equivalent gases have varied. Primary emissions (excluding fossil fuels emissions – another sector) are attributed to crop production, such as cereals and oilseeds, and livestock production, (beef, dairy, poultry and swine).
Climate Trace, a global non-profit coalition tracking GGEs by satellite and sensor data calculates Canada’s agriculture emissions as .74% of global agriculture emissions broken down further as three CO2e20 primary gases:
|2015-2021||0.71 B tonnes CO2e20||10.8 M tonnes carbon dioxide (CO2)||6.62 M tonnes methane (CH4)||0.54 M tonnes nitrous oxide (N2O)|
Trends during this period show CO2 reductions due to the adoption of Better Management Practices creating production efficiency improvements, such as reducing tillage intensity, shifting from summer fallow (leaving fields bare), increased conversion of annual to perennial crops to improve soil health with enhanced carbon storage in soil and better crop yields. Methane changes show a gradual reduction of cattle/pork populations, better livestock feed and more productive livestock breeds and N2O changes attributed to increased nitrogen fertilizer use, for example, corn, and some oilseed crops, particularly canola. A broader trend is the rising costs of inputs, land, machinery etc., fewer but larger farms, aging producers, and investor-owned lands.
Also, longer growing seasons and an increased extent of arable land moving north are impacted given climate change with increased precipitation (winter/spring), drier summers/falls, sudden storms creating floods/erosion, heat waves/droughts, wildfires, insects, stress to crops/livestock.
In 2015 and 2021 respectively, Climate Trace shows Canada’s agriculture CO2e20 emissions as:
|2015||0.10 B tonnes CO2e20||2.14 M tonnes CO2||0.94 M tonnes CH4||0.08 M tonnes N2O|
|2021||0.10 B tonnes CO2e20||1.16 M tonnes CO2||0.95 M tonnes CH4||0.08 M tonnes N2O|
Agriculture sub-sectors responsible (highest to lowest) during 2021 were 60.35 M tonnes enteric fermentation CO2e20, manure management 20.22 M tonnes CO2e20, synthetic fertilizer application 12.42 M tonnes CO2e20, other agricultural soil emissions 8.02 M tonnes CO2e20, cropland fires 1.65 M tonnes CO2e20 and rice cultivation 0.0 M tonnes CO2e20.
The largest sub-sector, enteric fermentation emissions (CH4) originate almost entirely from cattle (over 95%) and anaerobic decomposition of stored manure. Most of their feed is forage, notes Tim McAllister, Agriculture and Agri-Food Canada research scientist “where a lot of carbon sequestered in the ground as roots and grasses in those areas represent a significant carbon store.” CO2 and N2O result from manure, cropland, fertilizers and other production thus CH4 is a by-product of cattle’s digestion processes.
Research recommends large livestock operations manage manure emissions by capturing CH4 to generate heat and electricity as a viable option to reduce emissions. Addressing manure piles: by aerating them, stalling denitrification and reducing N2O emissions. Increasing farm production efficiencies through multi-product systems compared to single-product systems reduces emissions. In Australia, adding urease inhibitors to manure piles has reduced conversion from urea to N2O. Of course, eating less red meat and diversifying meat choices have an emissions impact.
The IISD recommends reducing chemical use, better crop rotations, rotational and mob grazing to improve pastures, and integrated crop and livestock rotations reducing the need for manure management practices and synthetic fertilizers. Government incentives, better livestock practices including manure management, feed practices of wild-foraged, or higher grain diets, (ie alfalfa), strategies to maximize herd health, and supplements to reduce digestive methane to reduce CH4.
A recent University of Calgary’s School of Public Policy report recommends no-till practices, optimizing animal feed and additives, feed supplements for improved digestibility, genetic selection and breeding, policies to expand anaerobic manure digestions, nitrification inhibitors and expanded use of controlled-release and stabilized fertilizers to reduce enteric fermentation.
Federal fund commitments (2021-2024) include improved farm nitrogen management, cover cropping, and rotational grazing under Agricultural Climate Solutions. Many farms have already taken steps but more targets, policies, industry support, data and roadmaps between improved practices and reduced climate risk to make efficiencies more economically viable for producers are needed.
This post was submitted by Climate Scorecard Canada Country Manager Diane Szoller