District Scale GHG Emission Indicators for Canadian Field Crop and Livestock Production

Abstract

The three main farm products from Canadian agriculture, i.e., proteins, vegetable oils, and carbohydrates, account for 98% of the land in annual crops in Canada. The intensities and efficiencies of these field crops in relation to their Greenhouse Gas (GHG) emissions were assessed for their value as land use change indicators. To facilitate spatial comparisons, this assessment was carried out at the Ecodistrict (ED) scale. The Unified Livestock Industry and Crop Emissions Estimation System (ULICEES) model was modified to operate at the ED scale, and used to quantify the GHG emission intensity of protein. GHG emissions were also calculated for plant products not used for livestock feed. The livestock GHG emissions and GHG-protein intensities estimated using ED scale inputs to ULICEES were reasonably close to GHG-protein intensities generated by the version of ULICEES driven by provincial scale census data. Carbohydrates were split into two groups, i.e., whether or not they supported livestock. Annual farm product data at 5-year intervals were used to generate GHG emissions from all farm operations. The range of GHG emissions from all farm operations in Western Canada was from 42 to 54 Mt CO2e between in 1991 and 2011, while GHG emissions from livestock ranged from 22 to 34 Mt CO2e over the same period. The Eastern Canadian GHG emissions from all farm operations declined gradually from 24 to 22 Mt CO2e over the period, with most of the eastern GHG emissions being from livestock. Ruminant livestock accounted for most of the livestock GHG emissions, particularly in the west. Provincial scale GHG emission efficiencies of the four farm product groups were assessed on a per-unit of GHG emissions basis for 2006. The most GHG-efficient province for protein was Ontario, whereas the most GHG-efficient province for all three plant products was Saskatchewan. The coastal provinces were the least GHG-efficient sources of all four farm product groups.

Potential Role for Consumers to Reduce Canadian Agricultural GHG Emissions by Diversifying Animal Protein Sources

“…This scenario analysis is underpinned by the GHG-protein indicator [6,10,15,17]. The starting point for this paper was the premise that both medical and producer considerations had a potential role to play in reducing livestock GHG emissions [6].…”

“…Broilers, a non-RM carcass commodity, were included with the two RM commodities, beef and pork, because an increase in non-RM protein sources would be needed to maintain the NPI as the projected RM consumption is reduced [6]. Protein is an ideal common denominator for comparing livestock GHG emissions [10,17]. However, this indicator does not account for livestock by products, which, at least for beef, can have appreciable market value [18].…”

“…The protein-based GHG emission intensity indicator [17,20] defined the minimum boundary condition for the recommended livestock consumption calculations. The latest of the six census years common to the three source papers and with both GHG and land use estimates [12][13][14] was 2001.…”

“…The effectiveness of the shift from beef to pork in reducing GHG emissions is demonstrated in Table 2 by the magnitude of ∆ 2 PS-4 being twice the magnitude of ∆ 2 PS-2. Although broilers are the most popular non-RM protein source [23], this commodity is only one example for how consumers can diversify their protein sources beyond RM [5], many of which have lower GHG-protein emission intensities than broilers [17,20]. The difference in GHG emission intensity between pork and broiler production was less than the difference between either of these two commodities and beef.…”

An economic analysis software for evaluating best management practices to mitigate greenhouse gas emissions from cropland

“…For example, the annual GHG emissions from farm operations ranged from 42 Mt to 54 Mt of CO2 equivalent (CO2 eq) in Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) from 1991 to 2011. At the same time, those in Eastern Canada (Nova Scotia, Ontario, Quebec, New Brunswick, Prince Edward Island, Newfoundland) ranged from 22 to 24 Mt CO2 eq annually (Dyer et al, 2018). As a matter of fact, Alberta has permitted the farmers to enter Alberta's carbon market by adopting an agricultural practice improvement since 2012 .…”