390
1960s as determined by DGVMs by incorporating the estimated budget residual in
response to the increase in cumulative atmospheric CO 2 (Fig. 18.4). This DGVM
mean of 2.8 ± 0.7 GtC/year is technically the observational average for 2006–2015,
which is estimated from the budget residual (Fig. 18.5).
Subsequently, the entire CO 2 land flux (S LAND − E LUC ), which is extended by
atmospheric inversion, is greatly beneficial to the calculation of the global budget,
G ATM , along with the assumption of relative uncertainty in S OCEAN and E FF due to the
inversions. The total land flux has the same magnitude considering the decadal
mean, which for 2006–2015 accounted for three inversions of 2.2, 2.3, and 3.4 GtC/
year relative to the total flux calculation of 2.1 ± 0.7 GtC/year using Eq. (18.1). The
total land sequestrations by these inversions are 1.8, 1.8, and 3.0 GtC/year including
the average of all reverse flux variables, 0.45 GtC/year. Interestingly, the inter- annual
variation within the inversions matched the residual-based S LAND very closely
(Fig. 18.5). Therefore, the total land fluxes determined by DGVM confirm that the
calculation of the carbon budget and its inversion in the atmosphere has a decadal
mean of 1.7 ± 0.5 GtC/year (Table 18.1 and Fig. 18.5).
Cumulative CO 2 Emissions and Atmospheric Impact
In this study, the total emission from fossil fuel burning and land-use change from
1870 to 2015 was calculated as 555 ± 55 GtC. Within the atmosphere, the emissions
are partitioned among the atmosphere (235 ± 5 GtC per the atmospheric CO 2 concentrations of 288 ppm in 1870 and 399.1 ppm in 2015), the ocean (160 ± 20 GtC),
and the land (160 ± 60 GtC). The total emissions during the preindustrial development period of 1750–1869 were 3 GtC for E FF and approximately 45 GtC for E LUC
(rounded to the nearest 5), of which 10 GtC was emitted in the 1850–1870 period
and 30 GtC in the 1750–1850 period for an average of 25 GtC, which revealed that
the atmospheric CO 2 concentration growth rate during this period was 25 GtC; that
of ocean sequestration was 20 GtC; and that of terrestrial land sequestration was 5
GtC [13, 35].
Based on the calculations in this study, the growth of the atmospheric CO 2
concentration (G ATM ) is projected to increase in 2016 to 6.7 ± 1.1 GtC
(3.15 ± 0.53 ppm). Combining the projected E FF and G ATM reveals that summing the
sequestration by the land and ocean and subtracting the emissions from land-use
change (S LAND + S OCEAN − E LUC ) only yield approximately 3 GtC. S OCEAN accounted
for 3.0 GtC in 2015 and is expected to increase in 2016 [31, 34], and E LUC accounted
for 1.3 GtC in 2015 with a decadal average of 1.0 GtC/year. Here, the remaining
terrestrial sequestration, S LAND , for 2016 is, as expected, far below the mean balance
of E LUC for 2006–2015 [17, 24]. Therefore, to determine the total carbon accumulated and its rate of increase in the atmosphere since 1750 or 2016, I have used the
atmospheric CO 2 concentrations of 288 ± 3 or 399 ± 3 ppm, respectively. The variation of ±3 ppm (converted to ±1σ) was obtained from IPCC data, and the rate of
growth of the atmospheric CO 2 concentration was calculated using MATLAB soft18 Air
1960s as determined by DGVMs by incorporating the estimated budget residual in
response to the increase in cumulative atmospheric CO 2 (Fig. 18.4). This DGVM
mean of 2.8 ± 0.7 GtC/year is technically the observational average for 2006–2015,
which is estimated from the budget residual (Fig. 18.5).
Subsequently, the entire CO 2 land flux (S LAND − E LUC ), which is extended by
atmospheric inversion, is greatly beneficial to the calculation of the global budget,
G ATM , along with the assumption of relative uncertainty in S OCEAN and E FF due to the
inversions. The total land flux has the same magnitude considering the decadal
mean, which for 2006–2015 accounted for three inversions of 2.2, 2.3, and 3.4 GtC/
year relative to the total flux calculation of 2.1 ± 0.7 GtC/year using Eq. (18.1). The
total land sequestrations by these inversions are 1.8, 1.8, and 3.0 GtC/year including
the average of all reverse flux variables, 0.45 GtC/year. Interestingly, the inter- annual
variation within the inversions matched the residual-based S LAND very closely
(Fig. 18.5). Therefore, the total land fluxes determined by DGVM confirm that the
calculation of the carbon budget and its inversion in the atmosphere has a decadal
mean of 1.7 ± 0.5 GtC/year (Table 18.1 and Fig. 18.5).
Cumulative CO 2 Emissions and Atmospheric Impact
In this study, the total emission from fossil fuel burning and land-use change from
1870 to 2015 was calculated as 555 ± 55 GtC. Within the atmosphere, the emissions
are partitioned among the atmosphere (235 ± 5 GtC per the atmospheric CO 2 concentrations of 288 ppm in 1870 and 399.1 ppm in 2015), the ocean (160 ± 20 GtC),
and the land (160 ± 60 GtC). The total emissions during the preindustrial development period of 1750–1869 were 3 GtC for E FF and approximately 45 GtC for E LUC
(rounded to the nearest 5), of which 10 GtC was emitted in the 1850–1870 period
and 30 GtC in the 1750–1850 period for an average of 25 GtC, which revealed that
the atmospheric CO 2 concentration growth rate during this period was 25 GtC; that
of ocean sequestration was 20 GtC; and that of terrestrial land sequestration was 5
GtC [13, 35].
Based on the calculations in this study, the growth of the atmospheric CO 2
concentration (G ATM ) is projected to increase in 2016 to 6.7 ± 1.1 GtC
(3.15 ± 0.53 ppm). Combining the projected E FF and G ATM reveals that summing the
sequestration by the land and ocean and subtracting the emissions from land-use
change (S LAND + S OCEAN − E LUC ) only yield approximately 3 GtC. S OCEAN accounted
for 3.0 GtC in 2015 and is expected to increase in 2016 [31, 34], and E LUC accounted
for 1.3 GtC in 2015 with a decadal average of 1.0 GtC/year. Here, the remaining
terrestrial sequestration, S LAND , for 2016 is, as expected, far below the mean balance
of E LUC for 2006–2015 [17, 24]. Therefore, to determine the total carbon accumulated and its rate of increase in the atmosphere since 1750 or 2016, I have used the
atmospheric CO 2 concentrations of 288 ± 3 or 399 ± 3 ppm, respectively. The variation of ±3 ppm (converted to ±1σ) was obtained from IPCC data, and the rate of
growth of the atmospheric CO 2 concentration was calculated using MATLAB soft18 Air