# Biomass Refined: 99% of Organic Carbon in Soils
## 3 Results and Discussion
### Primary Productivity (NPP), Soil Respiration (SR), and CO\({}_{2}\) Drawdown  
Global Gross Primary Productivity (GPP) mainly on land (Figure 9) is \(\sim\)440 Gt C/year, which, less plant respiration, gives about 220 Gt C/yr Net Primary Productivity (NPP, with only around 5-20 Gt C/yr Ocean NPP, or just \(\sim\)2-8%) after [16]. This also implies \(\sim\)890 Gt C currently in atmospheric CO\({}_{2}\) is recycled in (890/440 =) \(\sim\)2-year cycles on land via land-plant photosynthesis fixation and soil respiration/decomposition mainly by the soil biota. Despite \"official\" estimates of just 60-70 Gt C/yr land NPP (as in Table 1), isotopic evidence supports these much higher rates and [59] imply terrestrial NPP as much as 232.5-275 Gt C/yr, exceeding a value of 220 Gt C/yr NPP. Critical comments on [59] are that although they cite 1.5 years, they also state: \"_the entire atmospheric CO\({}_{2}\) turnover time is not much longer than the tropospheric mixing time (less than \(\sim\) 5 months)_\", implying a much shorter time. Moreover, they are inconsistent in their data with terrestrial surface flux (F\({}_{\rm sur}\)) either 465 \(\pm\) 60 Gt C/year or \"_terrestrial gross flux is quantified to be 550 \(\pm\) 60 PgC/year_\". This latter value, if correct, supports raising NPP (and other land fluxes). They state: \"_our **best estimate** for tGPP is \(\sim\) 170-200 PgC/year_\" [my bolding] and that \"_the_ [current climate] _models should be revisited to achieve a full understanding of ecosystem changes due to the changing climate and environmental factors_\". \begin{table}
\begin{tabular}{l l l} \hline
**Solid Component** & **Prior Values (Gt C)** & **Present Value (Gt C)** \\ \hline Mineral soil SOC & 1700 (or just “1417”) & 10,000 \\ Permafrost SOC & 1400 & 5000 \\ Peat p-SOC & (Included or 11237) & 3000 \\ Sediment SeSOC & 2500 & 2500 \\ Phytomans (plus other biota +) & 450+ & 2400++ \\ Litter/logs & 300 & 600 \\ Biocrust/ Phytomenon & - & 15 \\ SIC/DIC/DOC & 2305 & 7462 \\ \hline
**TOTAL** & **6350+** & **30,9777++ \({}^{*}\)** \\ \hline \end{tabular} \({}^{*}\)Logs/liter, biocrust, biota, and DOC sum to \(\sim\)1000 Gt C, plus SIC/DIC are doubled to 7410 Gt C to give a new total soil range \(>\)30,000 Gt C. This is likely a minimum as terrain and depth factors may well be higher. If the fossil fuel inventory of 5000–10,000 is included, a total is closer to 40,000 Gt C. NPP rates in Table 1 are not presented in the Table above but are reviewed in the following section.  
\end{table} 
Table 2: Summary of the global SOC status prior to the current review (as in Table 1) now refined. Indirect support is also provided by global levels of photosynthetic Rubisco enzymes. Recently, ref. [79] doubled Rubisco on land to about 0.7 Gt (96%) vs. 0.03 Gt (4%) in marine environments. The land component is based upon flat biomes and thus may be readily doubled to 1.4 Gt (or 98%). Relating to rates of NPP, their contrived catalysis rates are unconvincing if not patently false (as shown above for marine NPP). These authors' land NPP starting assumptions of just 60 Gt, now raised to 220 Gt C/yr, or about 96-98% of global total which is roughly commensurate with their 96-98% Rubisco level. An Oceanic value of 2-4% then equates to NPP reduced to just about 5-10 Gt C/yr. Rationale for raised land values is shown in self-explanatory images (Figures 13 and 14). Gradual increase in atmospheric CO\({}_{2}\) in the 120 years 1900-2020 was estimated at 280 ppm to 412 ppm, or a 32% rise, while terrestrial GPP increased 35% over the same period, mainly due to a CO\({}_{2}\) greening effect [47]. The inability of plants to drawdown excess CO\({}_{2}\) is likely due to forest clearance for crops and stock, erosion, and topsoil loss.