# Biomass Refined: 99% of Organic Carbon in Soils
## Appendix A Total Peat SOC (p-SOC)
They do attempt to differentiate, noting \"_Histels (perennially frozen peatland soils, Gelisols) and Histosols (unfrozen peatland soils)_\" with Gelisols (from Latin gelare, \"to freeze\") being soils of very cold climates that contain Permafrost within two metres of the surface. Nevertheless, the domains of Peat and Permafrost are somewhat intermixed and confused. Furthermore, in [161] Tropical peat depth of 11 m is only for Rwanda; other depths average 4-5 m with a mean ~4.5 m Tropical depth [162]. Confusingly, ref. [18] had: \"_An additional complication is that \(\sim\)300 Pg of the permafrost region soil carbon is stored in peatlands, which must not be counted twice_\". Probably a mistake, this contradicts their Permafrost peat (0-2 m) at 116 Gt SOC (by an extra ~184 Gt C!) and their non-Permafrost peat (0-3 m) already (427 + 92 + -40 =) \(\sim\)559 Gt SOC? If correct, would this not suggest global Peat to depth should be (559 + 300 =) 859 Gt rather than 675 Gt C? [PERSON] et al. may have limited depth for northern peatlands to 2.3 m (as per table 5 in ref. [160]); nevertheless, most other studies often tally total Peat at about ~600 Gt SOC. In effect, this would also remove 300 Gt C of peaks in Permafrost soils. Some Tundra region peats are claimed by [48] to total 1307 Gt SOC to depth, albeit they contrarily allow just 185 \(\pm\) 66 Gt C in Permafrost peatlands. Moreover, on Tropical peat depth and carbon stocks, ref. [163] had: \"_The best estimate of average peat thickness was 5.5 m and 7 m for Indonesia and Malaysia respectively\"_ and [161] expand on this: \"_The thickest peat deposits in this assessment are in Africa with best estimates of mean peat thickness of 11 m in Rwanda, 8 m in Burundi, 7.5 m in Congo, 5 m in Nigeria and 4 m in both Democratic Republic of Congo and Uganda. In Southeast Asia the thickest peat is in Malaysia and Brunei (7 m) followed by Indonesia (5.5 m). In Central America and the Caribbean, peat is thickest in Panama with a best estimate of 6 m, followed by Jamaia (5 m), Cuba (1.8 m) and Trinidad and Tobago (1.3 m). There is no information on peat thickness for most other countries in this region and the default best estimate of 0.5 m has been applied to them. South American petals seem to be shallower with a mean thickness of 4 m in Venezuela, 2 m in Brazil and 1.75 m in Peru.\"_ Their total tropical peat tally was 88.6 Gt C, as already noted, but this is lower than [162] with Tropical peat to mean depth around 3.5 m of up to 220 Gt C. This itself lower than [23] with 315 Gt C in Tropical peatlands. [164] had determined more Tropical peatland in South America than in SE Asia and to greater depths than previously estimated; thus, they reported a higher value yet of: \"_350 GtC, more than three times current_ estimates, e.g., of the mere 88 Gt C by [161]. Further, ref. [165] have: \"_Tropical peatlands play an important role in the global carbon cycle due to their immense storage capacity, preserving between 469 and 694 Gt C in a relatively small area (90-170 Mha), equivalent to one third of the total global carbon pool_\". Although a substantial contribution, not all of their data sources are traceable. Ref. [166] expand on SE Asia peat information but a summary in their report is elusive. Total Peat in [19] was 1683 Gt SOC but their source errors are noted above and in the Introduction. As already remarked on above, ref. [162] Tropical peat to mean depth of 3.5 m of up to 220 Gt C, although much shallower, is far above [PERSON] et al. 's 89 Gt C. In summary, assuming \(\sim\)2 m peat depth is unrepresentative, then an estimated 1325-1375 Gt C, doubled for true depth, ranges in both Boreal and Tropical peats, totals somewhere between 2246-2750 Gt p-SOC. However, if [24] value of \(\sim\)1030 Gt C in northern peatlands does allow total depth, the additional (315 + 15 = ) 330 Gt C in other regions, doubled (or quadrupled?) for depth of 2 m (or 4 m?) to 660 (or 1320? ), when added, totals \(>\)1690 Gt C (or 2350 Gt C?