Please find my comments in the attached file.

The  paper presents the C-PEAT Global Peatland Carbon Database v.2025, with 267 peat cores and large numbers of depth measurements, including dry bulk density, organic matter, carbon, nitrogen, raw chronological data, and calibrated ages.

Few comments

-The title says “Global Peatland Carbon Database”, which is fine   but the dataset is heavily dominated by northern extratropical sites.  This is a major limitation because tropical peatlands differ strongly in peat formation, hydrology,etc. The paper does clearly discuss this

Whether there is a possibility for future improvements for e.g. many data are now collected in the ttropics eg

Anshari, Gusti Z., et al. "Peatland inception and development across Kalimantan, Indonesia." Scientific Reports (2026).

-The manuscript says PANGAEA performed quality control, but it does not fully explain what was checked, what was corrected, and what remains uncertain. 

For example, Table 5 reports unrealistic values of max : dry bulk density values up to 3.380 g cm⁻³,  total carbon up to 100%, and nitrogen at 56.6%.  

- Table 6. The peat versus mineral soil comparison is interesting, but it is distracting. The comparison needs more caution because NCSS is not a globally representative mineral-soil dataset in the same way that C-PEAT is not globally representative of peatlands. Also, the NCSS table includes impossible or problematic values such as negative SOC and coarse fraction up to 4229%,

- The manuscript compares C-PEAT with the NCSS pedon database and reports that “On average, soil organic carbon content for the top 100 cm was 16 times greater in peat soils 17.53 g cm⁻² than in mineral soils 1.08 g cm⁻².” This seems to be erroneous

SOC stock=bulk density×C fraction×depth

For the top 100 cm: 0.140×0.467×100=6.54 g C /cm2

Alternatively, using their reported mean organic C density: 0.058×100=5.8 g C /cm2

So the cited value does not make sense

-“C-PEAT GD contains 267 cores”, explain whether duplicate cores across previous syntheses were reconciled and how.

“carbon content values (total carbon and carbon combined)”  Better “C%, TC%, and TOC% records combined.”

-The paper includes age determination and calibrated age parameters, but the treatment of chronological uncertainty is still descriptive. The number of chronological constraints varies from 1 to 41 per core, with a median of 6, and the average is only 0.76 dates per 1000 years. That means carbon accumulation rates can be highly uncertain

-For a data  paper, the question is: How should users use this database correctly? The paper has usage notes, but they are too general.

The database is useful for summarising peat properties, analysing Holocene apparent carbon accumulation rates, and benchmarking Earth system models, and global mapping of peat properties. See also recent peat data and mapping effort that the C-peat can contribute to

Skye et al. "Peat-DBase v. 1: a compiled database of global peat depth measurements." Earth System Science Data Discussions 2025 (2025): 1-26.

Widyastuti et al. "Digital mapping of peat thickness and carbon stock of global peatlands." Catena 258 (2025): 109243.

The writing is generally clear but somewhat sloppy in presentation, mainly because of inconsistent terminology, awkward phrasing, formatting errors.

Some examples:

L.39 "peat soil-c density" -> "peat soil C density" or "peat-soil C density"

L.63–64 "The need for transparency in methods, code, and data have also been fueling..." -> "The need for transparency in methods, code, and data has.."

L.79 "provides means to assess" -> "a means to assess"

L.97 "with the latter also acknowledging..." -> "Fig. 2 also acknowledges..."

L.128 "peatland C storage (kgC)" -> "peatland C storage (kg C)"

L.129 "C density (kgC/m2)" -> "C density (kg C m⁻²)"

L.131 "gC/m2/yr" -> "g C m⁻² yr⁻¹"

L.143 "the use of these datasets come with important limitations" -> "the use of these datasets comes with important limitations"

L.212 "4 thesis, dissertations, and conference papers" -> "4 theses "

L.233 "labs where the analysis were performed" -> "laboratories where the analyses were performed"

L.252,259, 310 "representativity" -> "representativeness"

L.260 "MAT and MAP was extracted" -> "MAT and MAP were extracted"

L.268 "we also contrast changes" -> "we also contrasted changes"

L.315–320 "KoppenGeiger" / "Koppen climate classes" -> "Köppen–Geiger" / "Köppen climate classes"

L.344 "g/cm3" -> "g cm⁻³"

L.367 "may be used as references" -> "may be used as reference values"

L.403–405 "IQT" -> "IQR"

L.405 "1.5 x IQT" -> "1.5 × IQR"

L.431 "Soil Organic Carbon" -> "soil organic carbon"

L.455 "some of them may not have reached" -> "some cores may not have reached"

L.456 "Along those lines" -> "Similarly" or "In addition"

L.459 "collected near the edge" -> "collected near basin margins"

Etc.