Table 3.
O2-based global carbon budget 1990–2000
| Budget item | Pg of C yr−1
|
|
|---|---|---|
| Manning (33) | Revised budget | |
| Fossil-fuel burning | 6.33 ± 0.4 | 6.33 ± 0.4 |
| Atmospheric CO2 increase | 3.21 ± 0.1 | 3.21 ± 0.1 |
| Total ocean CO2 sink | 1.68 ± 0.5 | 1.86 ± 0.6 |
| Total land CO2 sink | 1.44 ± 0.7 | 1.26 ± 0.8 |
Budgets are based on the decadal trend in atmospheric O2/N2 ratio at two northern hemisphere stations in the Scripps O2/N2 network. Manning (33) assumes Z = 0.16 ± 0.16 × 1014 mol of O2 yr−1; revised budget assumes 0.29 ± 0.4 × 1014 mol of O2 yr−1 (see text). Budgets differ in assumed ocean warming rate, and in assumed oceanic O2 outgassing per unit warming. Both budgets allow for outgassing of N2 (which affects the observed O2/N2 ratio) at a rate based on N2 solubility of 2.2 nmol of N2 per J of warming.