Table 3 Latitudinal CH4 emissions, carbon burial, and offsets in mangroves.

Mangrove latitudinal areas are based on Giri et al. (25). Error (±) is scaled error (see text) unless marked with “a” (in these cases, the SE is used).

LatitudeMangrove
area (km2)
Average
CH4 flux
rate
(μmol m−2
day−1)*
Latitudinal
CH4
emission
(Tg CH4
year−1)
Latitudinal
CH4
emission
(Tg C
year−1)
Latitudinal
CH4
(CO2 eq.)
emission,
GWP20 (Tg
C year−1)
Latitudinal
CH4
(CO2 eq.)
emission,
GWP100
(Tg C year−1)
Average
burial
rate
(g C m−2
year−1)
Latitudinal
carbon
burial
(Tg C year−1)
Offset
(%)
Sensitivity
analysis
offset
range (%)
0–5°44,00040.26
(± 40.3)a
0.010
(± 0.005)
0.008
(± 0.004)
0.24
(± 0.12)
0.10
(± 0.05)
396.6
(± 108.5)a
17.45
(± 4.78)
1.4(1.0–1.6)
5–10°30,000143.8
(± 78.3)a
0.025
(± 0.013)
0.019
(± 0.009)
0.59
(± 0.29)
0.23
(± 0.12)
651.0
(± 298.0)a
19.53
(± 8.94)
3.0(2.8–3.1)
10–15°23,500251.0
(± 72.8)a
0.034
(± 0.006)
0.026
(± 0.004)
0.81
(± 0.14)
0.32
(± 0.05)
286.8
(± 63.3)a
6.74
(± 1.49)
12.0(11.5–12.7)
15–20°16,500265.1
(± 95.5)a
0.026
(± 0.001)
0.019
(± 0.001)
0.60
(± 0.03)
0.24
(± 0.01)
104.4
(± 10.4)a
1.72
(± 0.17)
34.8(33.4–36.5)
20–25°18,800800.5
(± 310.4)a
0.088
(± 0.032)
0.066
(± 0.024)
2.06
(± 0.75)
0.81
(± 0.30)
166.6
(± 50.7)a
3.13
(± 0.95)
65.8(63.2–67.2)
25–30°4,300264.1
(± 50.3)a
0.007
(± 0.003)
0.005
(± 0.002)
0.16
(± 0.06)
0.06
(± 0.02)
182.8
(± 19.7)a
0.79
(± 0.08)
19.8(13.5–24.8)
30–35°310194.9
(± 18.9)a
0.0004
(± 0.0001)
0.0003
(± 0.0001)
0.008
(± 0.003)
0.003
(± 0.001)
182.8
(± 19.7)a
0.057
(± 0.006)
14.6(10.0–18.3)
35–40°350125.7
(± 88.1)a
0.0003
(± 0.0001)
0.0002
(± 0.0001)
0.006
(± 0.002)
0.002
(± 0.001)
182.8
(± 19.7)a
0.064
(± 0.007)
9.4(6.4–11.8)
TotalAverageTotalTotalTotalTotalAverageTotalAverageRange
Latitudinal
total
137,760260.6
(± 94.3)a
0.191
(± 0.057)
0.143
(± 0.043)
4.47
(± 1.34)
1.77
(± 0.53)
269.2
(± 73.7)a
49.48
(± 16.4)
20.1(17.7–22.0)

*Combined sediment-atmosphere and water-atmosphere flux accounting for mangrove ecosystems being inundated 50% of the time (water-atmosphere flux) and exposed 50% of the time (sediment-atmosphere flux; see table S4).

†Offset is calculated from carbon burial (Tg C year−1) and the CH4 flux using the GWP20 (Tg C year−1).

‡Carbon burial rates (Tg C year−1) and CH4 emissions (GWP20, Tg C year−1) are adjusted up and down by their scaled errors.