Home Methodology & sources

Methodology & sources

Cairn exists to be auditable. Every number on this site traces back to a versioned, pinned official source, transformed by reviewed code. This page records the provenance and the known limitations — read it before quoting a figure.

Sources

Source Role Dataset Release pinned in
CBS StatLine 85669NED Sector benchmark (whole-economy denominator) GHG emissions per climate sector, IPCC method, annual sources/cbs/manifest.yml
euets.info Installation benchmark (large-emitter numerator) Reprocessed EU Transaction Log, per-installation verified emissions + native NACE sources/euets/manifest.yml
EEA Union Registry Cross-check & denominator Official aggregate by country × activity × year sources/eea/manifest.yml

Each source's exact release is pinned by sha256 in an append-only manifest. A weekly CI job re-verifies the pinned raw files; a change is an integrity alarm, not flakiness.

Sector benchmark (CBS) — method & limitations

Headline gas: total greenhouse gases (CO₂-eq). Only leaf climate-sector categories are summed, so the national total is partitioned exactly once. CBS source categories are mapped to NACE sections via a version-controlled seed (sector_mapping_cbs); the mapping is reviewed via PR so its numeric impact shows up in a CI benchmark diff.

  • Provisional years are excluded (Definitief only), so the latest year may lag.
  • ~30–35% of national emissions land in UNMAPPED — households, land use, transport, and the CBS G–U services aggregate, which CBS does not attribute to a single NACE section. They are still counted, just not sector-attributed.
  • Unit is megatonnes (CBS "miljard kg CO₂-equivalent"), rounded by CBS to 0.1 Mt.
  • Bunkers are IPCC memo items outside the national total and are excluded.

Installation benchmark (EU ETS) — method & limitations

NL registry, euets trading system only (linked Swiss chets duplicates excluded), stationary installations only (aircraft/maritime excluded), verified emissions only. Sector = NACE section, native to the source. The sector mean/median are computed across the NL stationary ETS population per (NACE section, year). A coverage test reconciles the ETS total against the EEA aggregate (both derive from the EUTL; they match to ~0.02%).

  • This is the ETS large-emitter average, not the whole-economy sector average — use the sector page for that.
  • euets.info lags the EEA release (latest data ~2023 vs ~2025).
  • Installations without a NACE code are excluded (cannot be sector-benchmarked).

Classification basis

The mapping rests on SBI 2008 ⊃ NACE Rev.2. Both are migrating (NACE Rev.2.1 from 2025; SBI 2025 from 2026); when CBS switches 85669NED over, the seed mapping and the NACE section letters are revisited as a reviewed methodology change.

References