# Biomass Refined: 99% of Organic Carbon in Soils
## 3 Results and Discussion
### Total Global Soil SOC Refined
#### 3.5.8 Dissolved Organic Carbon (DOC) in Soils  
An estimate is of \(\sim\)13 Gt DOC in soils to 1 m depth [52; 135]; doubled, at least, for depth and possibly again for terrain, would raise this to 52 Gt DOC. Subsequently, ref. [136] estimated annual carbon release from DOC as 27.98 Gt C/yr; they say is three times greater than global fossil fuel carbon emissions from IPCC (of \(\sim\)9 Gt C/yr). Moreover, ref. [137]has \(\sim\)2-5 Gt/yr DOC/DIC processed by water. These will increase as Pernafrost melts further [53, 135].  
DOC intergrades with Soil Inorganic and Dissolved Inorganic C: viz. (SIC) and (DIC).  
3.5.9. Soil Inorganic Carbon (SIC) and Dissolved Inorganic Carbon (DIC) in Soils  
Earlier studies by [138] were updated by [50], who found: _\"Inorganic C as soil carbonate (2255 Pg C down to 2 m depth) and as bicarbonate in groundwater (1400 Pg C) together surpass SOC (2400 Pg C) as the largest terrestrial C pool\"_. Another recent report by [51] claims soil inorganic carbon is slightly higher at 2305 \(\pm\) 636 (\(\pm\)1 SD) Gt SIC to 2 m soil depth. Doubled for depth and/or terrain ups these latter SIC plus DIC values, giving total (2305 + 1400 = 3705 \(\times\) 2 = ) 7410 Gt SIC/DIC.  
It is possible that those dissolved portions of SIC within the water table, being at its own levels, as found in DIC, are not so obviously increased. Figure 12 summarizes this.  
As already noted, a mean soil depth of \(>\)13-21 m is six or ten times deeper than most samples, thus these values may truly be much higher. Moreover, terrain may factor in yet higher for SIC but possibly not so much, if at all, for DIC that finds its own level.  
Calcite (crystalline CaCO\({}_{3}\)) that contains about 12% carbon may be included in soil inorganic SIC totals as a minor but valid earthworm exudate mainly from atmospheric CO\({}_{2}\). Blakemore (2019--[[https://vermecology.wordpress.com/2019/11/11/earthworm-cast-](https://vermecology.wordpress.com/2019/11/11/earthworm-cast-)]([https://vermecology.wordpress.com/2019/11/11/earthworm-cast-](https://vermecology.wordpress.com/2019/11/11/earthworm-cast-)) carbon-storage-ecces/, accessed on 11 November 2024) estimated \(\sim\)1 Gt C/yr earthworm calcite, which is more than all the solid CaCO\({}_{3}\) in shells of all marine organisms, of just 0.7 Gt C/yr (IPCC 2001: 198--[[https://www.ipcc.ch/report/ar3/wg1/the-carbon-cycle-a](https://www.ipcc.ch/report/ar3/wg1/the-carbon-cycle-a)]([https://www.ipcc.ch/report/ar3/wg1/the-carbon-cycle-a](https://www.ipcc.ch/report/ar3/wg1/the-carbon-cycle-a)) nd-atmospheric-carbon-dioxide/, accessed 11 November 2024). Over the millennia, this would be a sizeable contribution from earthworms to SIC and DIC, especially since AR5 figure 10.5 in ref. [41] shows rock weathering less than this at just 0.1-0.3 Gt C/yr.  
Also noted above, in addition to DIC, the new total of dissolved organic DOC, that may, or may not, be counted within routine soil samples, amounts to \(\sim\)52 Gt DOC. When combined, these estimates of SIC/DIC/DOC add up to around (\(>\)7410 + 52 =) \(>\)7462 Gt C.