{
  "meta": {
    "name": "Aftermine abandoned-mine methane dataset",
    "version": "1.0.0",
    "released": "2026-08-02",
    "status": "venture research artefact — not peer-reviewed",
    "licence": "CC BY 4.0 — cite the underlying primary sources when reusing figures",
    "provenance": "Derived from the Aftermine field study; every record carries an evidence label. Primary sources: Global Energy Monitor Global Coal Mine Tracker abandoned-mine methane dataset (June 2024); Regulation (EU) 2024/1787; IPCC AR6 WG1 Table 7.15; Kholod et al. 2020 (doi:10.1016/j.jclepro.2020.120489); UNECE Best Practice Guidance No. 64.",
    "evidence_labels": {
      "measured": "Read from an instrument at the mine or emission source, with a stated method and date",
      "reported": "Published by an authority, operator, inventory or dataset — a record, not an instrument reading",
      "reference": "A scientific constant or conversion factor from published literature",
      "modelled": "Produced by a published model from stated inputs",
      "estimated": "Derived from analogues or expert ranges",
      "conflicting": "Two or more credible sources disagree",
      "unknown": "No defensible value is available"
    },
    "scope": {
      "geography": "European Union",
      "mine_type": "underground hard-coal mines (surface mines counted but not modelled)",
      "closure_window": "operations ceased 2015-2023 as recorded by GEM June 2024",
      "note": "This is NOT all EU abandoned mines; national inventories using different populations and methods report materially different totals (see conflicts)."
    }
  },
  "inventory": {
    "counts": { "total": 70, "underground": 53, "surface": 17, "evidence": "reported" },
    "flooded_status_of_underground": { "unknown": 34, "dry": 13, "flooded": 6, "evidence": "reported" },
    "annual_methane": {
      "unit": "kt CH4/yr",
      "range_min": 185,
      "range_max": 200,
      "midpoint_convention": 193,
      "evidence": "modelled",
      "note": "Range spans the all-unknown-flooded (185) to all-unknown-dry (200) scenarios; the midpoint is a convention, not a probability-weighted estimate.",
      "scenarios": [
        { "label": "all unknown-status mines assumed dry", "mcm_per_yr": 298.2, "kt_per_yr": 200 },
        { "label": "all unknown-status mines assumed flooded", "mcm_per_yr": 275.7, "kt_per_yr": 185 },
        { "label": "every mine assumed flooded (best case)", "mcm_per_yr": 238.7, "kt_per_yr": null }
      ]
    },
    "conflicts": [
      {
        "claim": "EU 2023 GHG inventory attributes 235 kt CH4 (2021) to abandoned underground mines",
        "against": "GEM asset-level dataset finds ≈193 kt for 2015-2023 closures only; Romania's own UNFCCC reporting alone claims ≈195 kt",
        "evidence": "conflicting",
        "interpretation": "plausibly different mine populations, reporting years and methods (asset-level modelling vs national inventory accounting); unresolved"
      }
    ]
  },
  "mines": [
    { "id": "csa", "name": "ČSA Coal Mine", "country": "Czech Republic", "closed": 2021, "closed_evidence": "reported", "mcm_ch4_per_yr": 36, "emissions_evidence": "modelled", "flooded_status": "unknown" },
    { "id": "auguste-victoria", "name": "Auguste Victoria Colliery", "country": "Germany", "closed": 2015, "closed_evidence": "reported", "mcm_ch4_per_yr": 28, "emissions_evidence": "modelled", "flooded_status": "unknown" },
    { "id": "myslowice-wesola", "name": "KWK Mysłowice-Wesoła I", "country": "Poland", "closed": null, "closed_evidence": "unknown", "mcm_ch4_per_yr": 26, "emissions_evidence": "modelled", "flooded_status": "unknown" },
    { "id": "darkov", "name": "Darkov Mine", "country": "Czech Republic", "closed": 2021, "closed_evidence": "reported", "mcm_ch4_per_yr": 24, "emissions_evidence": "modelled", "flooded_status": "unknown" },
    { "id": "rydultowy", "name": "KWK Rydułtowy I", "country": "Poland", "closed": null, "closed_evidence": "unknown", "mcm_ch4_per_yr": 19, "emissions_evidence": "modelled", "flooded_status": "unknown" },
    { "id": "prosper-haniel", "name": "Prosper-Haniel Mine", "country": "Germany", "closed": 2018, "closed_evidence": "reported", "mcm_ch4_per_yr": 18, "emissions_evidence": "modelled", "flooded_status": "unknown" }
  ],
  "six_mines_total": { "mcm_per_yr": 152, "kt_per_yr": 102, "evidence": "modelled", "note": "≈ half of the study-inventory total" },
  "countries": [
    { "name": "Poland", "mcm_per_yr": 110, "evidence": "modelled", "note": "≈40% of study-inventory abandoned-mine methane" },
    { "name": "Czech Republic", "mcm_per_yr": 90, "evidence": "modelled", "note": "ČSA and Darkov are ≈70% of the country's total" },
    { "name": "Germany", "mcm_per_yr": 55, "evidence": "modelled", "note": "reportedly utilises ≈99% of its captured abandoned-mine methane; denominator (captured vs total) unresolved in sources" }
  ],
  "regulation_eu_2024_1787": {
    "evidence": "reported",
    "milestones": [
      { "date": "2025-08-05", "article": "Art. 25(1)", "obligation": "member state inventories of closed and abandoned underground coal mines (operations ceased after 3 Aug 1954)" },
      { "date": "2026-05-05", "article": "Art. 25(2)", "obligation": "methane measurement on inventoried elements emitting above 0.5 t CH4/yr" },
      { "date": "2026-08-05", "article": "Art. 25(6)", "obligation": "first yearly source-level emissions reports; annually by 31 May thereafter" },
      { "date": "2027-02-05", "article": "Art. 26(1)", "obligation": "member state mitigation plans, closed and abandoned mines alike" },
      { "date": "2030-01-01", "article": "Art. 26(2)", "obligation": "venting and flaring prohibited; exceptions only for demonstrated infeasibility or safety" }
    ]
  },
  "constants": {
    "gwp20_fossil_ch4": { "value": 82.5, "uncertainty": 25.8, "evidence": "reference", "source": "IPCC AR6 WG1 Table 7.15" },
    "gwp100_fossil_ch4": { "value": 29.8, "uncertainty": 11, "evidence": "reference", "source": "IPCC AR6 WG1 Table 7.15" },
    "ch4_density_kg_per_m3": { "value": 0.67, "evidence": "reference", "source": "IPCC 2006 convention, 0 °C and 1 atm", "note": "1 MCM CH4 ≈ 0.67 kt CH4" }
  },
  "mitigation_ladder": {
    "unit": "kt CH4/yr",
    "note": "Gross modelled source emissions. NOT technically addressable, NOT economically addressable, NOT expected destruction — each of those is a strictly smaller number that this dataset does not yet quantify.",
    "rungs": [
      { "label": "one good site", "min": 1, "central": 2, "max": 3, "evidence": "estimated" },
      { "label": "the six named mines", "central": 102, "evidence": "modelled" },
      { "label": "study-inventory range (53 underground mines)", "min": 185, "central": 193, "max": 200, "evidence": "modelled" },
      { "label": "global abandoned coal mines", "min": 4500, "max": 5000, "evidence": "estimated" }
    ]
  }
}