Agriculture Reference
In-Depth Information
TABLE 6:
Changes in soil carbon and annual GHG emissions due to beef to pork
redistribution, and payback periods required for decreased GHG to compensate soil carbon
losses, under four scenarios 1 for using residual land 2 in 2001.
Scenario #
1
2 3 4
Soil carbon loss over 40 years (Tg CO2e)
East
0.10
9.57
2.12
1.67
West
7.67
54.48
15.48
13.32
Canada
7.77
64.06 17.60 14.99
Decrease 3 in annual GHG emissions (Tg CO2e)
East
0.43
0.24
0.02
0.08
West
2.04
1.75
0.56
0.23
Canada
2.46
2.02
0.59
0.15
Payback period (years)
East
0.2
40.1
92.7
-
West
3.8
31.2
27.6
57
Canada
3.2
31.9
29.9
96.9
1
scenarios include four uses of residual land for crop or beef production
2
residual land includes the area freed by displaced beef population
3
negative quantities represent an increase in annual emissions
The estimated annual GHG emissions from ∆rA under the four scenar-
ios are shown in Table 5. These GHG emissions were subtracted from the
GHG reductions in Table 4 to estimate the net changes in GHG emissions
under each scenario. Due to enteric methane, the highest GHG emissions
resulted from Scenario 4, followed by Scenario 3. The fertilizer N
2
O and
fossil CO
2
from farm fi eld operations under Scenario 2 resulted in lower
annual GHG emissions than from Scenarios 3 and 4. There were no GHG
emissions from ∆rA under Scenario 1 since ∆rA is supposed to remain
under perennial forage.
The expected 40 year losses in soil carbon [40] as a result of the four
scenarios are shown Table 6 (rows 1 to 3). The net changes in annual GHG
emissions associated with each of the four scenarios are then presented
(rows 4 to 6). In Scenario 1, the net annual reduction in GHG emissions
from Table 4 were compared to the changes in soil carbon under ∆cA.
