Table 2. Accounting of soil organic carbon in top 1m in areas of agricultural frontiers and resulting potential carbon emissions under RCP 8.5 and RCP 4.5.
Rows with grey shading apply GAEZ general soil suitability constraints and soil requirements for each crop to the climatically suitable frontier areas.
| Landcover classification | Soil organic carbon stock (GT) 1m | Low-end IPCC method estimate C release (GT) [forest 25%; grass/shrubland 10%; wetlands 20%] | High-end IPCC method estimate C release (GT) [forest 25%; grass/shrubland 10%; wetlands 110%] | 1m estimate C release (GT) [all land classes 25%] | 1m estimate C release (GT) [all land classes 40%] |
|---|---|---|---|---|---|
| Forests (RCP 8.5) | 267.5 [192.6–355.4] | 66.9 [48.1–88.9] | 66.9 [48.1–88.9] | 66.9 [48.1–88.9] | 107.4 [77.0–142.2] |
| 243.3 [174.6–328.6] | 60.8 [43.7–82.2] | 60.8 [43.7–82.2] | 60.8 [43.7–82.2] | 97.3 [69.9–131.5] | |
| Shrubland/Grassland (RCP 8.5) | 286.6 [133.6–564.0] | 28.7 [13.4–56.4] | 28.7 [13.4–56.4] | 71.6 [33.4–141.0] | 114.6 [53.5–225.6] |
| 265.9 [118.7–532.5] | 26.6 [11.9–53.3] | 26.6 [11.9–53.3] | 66.5 [29.7–133.1] | 106.4 [47.5–213.0] | |
| Permanent wetlands (RCP 8.5) | 73.6 [56.6–74.3] | 14.7 [11.3–14.9] | 81.0 [62.3–81.7] | 18.4 [14.2–18.6] | 29.4 [22.7–29.7] |
| 54.2 [54.8–38.5] | 10.8 [7.7–11.0] | 60.3 [42.3–59.6] | 13.5 [9.6–13.7] | 21.7 [15.4–21.9] | |
| Total soil organic carbon (RCP 8.5) | 632.4 [400.0–991.5] | 110.2 [72.8–160.1] | 176.5 [123.8–226.9] | 158.1 [100.0–247.9] | 251.1 [153.1–397.5] |
| 569.2 [347.6–914.0] | 98.2 [63.2–146.4] | 147.0 [97.8–195.7] | 142.3 [86.9–228.5] | 225.3 [132.7–366.4] | |
| Forests (RCP 4.5) | 271.9 [197.4–353.8] | 68.0 [49.3–88.4] | 68.0 [49.3–88.4] | 68.0 [49.3–88.4] | 109.8 [78.9–141.5] |
| 248.3 [178.9–326.7] | 62.1 [44.7–81.7] | 62.1 [44.7–81.7] | 62.1 [44.7–81.7] | 99.3 [71.5–130.7] | |
| Shrubland/Grassland (RCP 4.5) | 196.5 [77.2–434.9] | 19.7 [7.7–43.5] | 19.7 [7.7–43.5] | 49.1 [19.3–108.7] | 78.6 [30.9–174.0] |
| 178.1 [67.6–401.3] | 17.8 [6.8–40.1] | 17.8 [6.8–40.1] | 44.5 [16.9–100.3] | 71.2 [27.1–160.5] | |
| Permanent wetlands (RCP 4.5) | 71.5 [39.6–74.3] | 14.3 [7.9–14.9] | 78.6 [43.6–81.7] | 17.9 [9.9–18.6] | 28.6 15.9–29.7] |
| 52.4 [26.2–54.8] | 10.5 [5.2–11.0] | 57.7 [28.9–60.3] | 13.1 [6.6–13.7] | 21.0 [10.5–21.9] | |
| Total soil organic carbon (RCP 4.5) | 539.9 [314.2–862.9] | 101.9 [65.0–146.8] | 166.2 [100.7–213.6] | 135.0 [78.5–215.7] | 215.9 [125.7–345.2] |
| 470.8 [272.8–771.3] | 90.4 [56.7–132.8] | 137.5 [80.3–182.1] | 119.7 [68.2–195.7] | 191.5 [109.1–313.1] |