Resources

1Core definitional principle

The key point where Layer 0 departs from the UNEP IRP approach is this: UNEP IRP GMFD counts "everything touched in the ground / nature" - including flows that never actually leave the site or enter the market, such as raw/gross ore (including gangue and waste rock), crop residues, and grazed biomass. Layer 0, by contrast, counts only the mass that actually leaves the site and enters a real market.

This principle gives a consistent framework for deciding which figure counts as "correct" in the table: for every row, the question asked was "is this mass actually being moved from one place to another and sold?"

2Reconciling with UNEP IRP

Unit-error detection: The values in the UNEP reference table were labeled "(kg)." Summing the 13 categories produced 107 billion units; this matched the global annual extraction figure UNEP IRP itself reports in its own publications (100-110 billion tons). Conclusion: the table's unit was tons, not kg - identified and corrected as a labeling error in the source table.

3Independent validation sources

In addition to the UNEP comparison, each category was cross-checked against at least one independent third-party source. Validation method: for each category, UNEP's relevant sub-total was placed side by side with the independent source's most recent global production figure; where the difference exceeded 15%, it was determined whether the gap stemmed from a difference in accounting basis or from a genuine data error.

4What came out

5Where the limits are, extraction

6Completing the picture with trade data

In addition to Layer 0's extraction figures, a separate exercise was carried out to map physical trade flows from country to country. UNEP IRP GMFD has no bilateral (country-to-country) flow data - it reports only country totals. The actual bilateral source is BACI (CEPII) - the version widely accepted as the academic standard, which cleans up UN Comtrade's mirror-statistics inconsistencies and produces a single reconciled figure. HS6 code mapping was carried out for all 29 categories (below).

7Flow, stock, reserve - three states of the same material

§2-§7 build Layer 0's flow figure: the 85 Gton the world pulls out of the ground each year. This section adds two more questions about the same material - how much of what has been extracted so far is still in use (stock), and how much is left in the ground, lasting how many years at today's rate (reserve). Each category falls into one of three groups by behaviour:

8In-use stock (the technosphere)

Primary source: Krausmann, Wiedenhofer, Lauk, Haas, Tanikawa, Fishman, Miatto, Schandl, Haberl (2017), "Global socioeconomic material stocks rise 23-fold over the 20th century and require half of annual resource use", PNAS 114(8):1880-1885. Measured in-use stock in 2010 was 792 Gton (±5%); it grew 23-fold over 1900-2010; roughly half of all material extracted each year goes into building or renewing stock. Net additions to stock (NAS) 30 Gton/year (Krausmann et al. 2018, "From resource extraction to outflows of wastes").

9Reserve figures: source by source

R/P = known reserves ÷ annual production. Not "years left" - how long today's known reserves last at today's rate. Reserves shift every year with price, technology and discovery; historically most metals' reserves have grown despite consumption. Every figure below is taken from the source and rounded: the order of magnitude is right, no decimal precision is claimed.

10Where the limits are, stock & reserve

The figures on the "Stock & Reserve" page are not all at one level of certainty - some are measured directly from a primary source, some are a sourced educated guess. The page shows each number plainly; how solid each one is lives here. Confidence 0-100: 90+ direct primary source; 70-85 primary source + unit conversion / aggregation; 55-70 sourced educated guess (no global numeric data). Full item-by-item rationale: docs/layer0_stock_reserve_methodology.md in the civilization-dynamics repo.

11Historical series (Historical Development page)

§2-§11 build a snapshot of today. A separate Historical Development page (/layer0/tarihsel) tracks three Layer 0 magnitudes across 14 time points from 10,000 BCE to today: population, annual material extraction (Gton), and average logistics distance (km). For 10,000 BCE - 1800 CE material is built as population × a per-capita material coefficient (the agrarian era is smoothed; consistent with Krausmann's 1900 narrow-basis 2.3 t/person). From 1900 on it uses the Krausmann et al. 2009 Table 1 narrow basis directly - the primary-crop + wood share of biomass + fossils + metal ores + industrial minerals + construction minerals; 2025 = the Layer 0 model (85 Gton). Logistics distance is local in prehistory (10 km) and 1,566 km today (Layer 0's BACI trade study, §7).

Derived series (no new sourcing, same build): material per capita, material intensity (kg per $ of GDP), transport work (Gton × km) total and per capita, a decomposition of material growth (population effect vs per-capita intensity - a log decomposition), and the growth rate + doubling time. Full source list and method: docs/layer_history_methodology.md in the project repository.

12Perspective pages, Critical Chokepoints, Decoupling, Planetary Impact

The pages in the "Perspective" group of the Detailed Analysis section read Layer 0 from a new angle. Decoupling (/layer0/detay/decoupling) adds no new sourcing; it derives from the historical series in §11 (GDP, mass, kg/$). Planetary Impact (/layer0/detay/gezegene-etki) draws on two sources: the mass-balance part derives from the stock/reserve work in §8-§10; the thermodynamic-cost, deep-time, mass-balance and planetary-boundaries parts are a separate dataset (layer0_planetary_cost.json) compiled from published academic headline figures, outside the main pipeline. Critical Chokepoints (/layer0/detay/bogazlar) is likewise a separate compiled dataset (layer0_chokepoints.json).