# Methods: the vintages our figures cite

Every figure we publish names the dated vintage it was computed under. Each vintage is a file whose SHA-256 a reader can recompute.

Our records follow the SSP² specification, version 0.4.1, deposited with its compliance vectors and profile definitions as vintage 2.[^c1]

Emission estimates for Australian agriculture use the factor vintage `hdp-ef-au-ag-ghg-2026-v2` for activity dated from 1 July 2026. It holds the VEERG V1 factors and was registered on 22 October 2026 as an errata of `hdp-ef-au-ag-ghg-2026-v1`, with the same factors and an earlier start date.[^c2]

Scope 3 inputs use the factor vintage `hdp-ef-au-ag-inputs-2026-v2`[^c3], and agricultural chemicals use `hdp-ef-au-ag-agrichem-2026-v2`[^c5], for activity dated from 1 July 2026. They were registered on 22 October 2026 as errata of the `-v1` sets, with the same factors and an earlier start date. Activity dated before 1 July 2026 has no Scope 3 factor set.

Activity dated before 1 July 2026 is estimated under the prior vintage, `hdp-ef-au-ag-ghg-gaf30-2026-v1`: GAF release 3.0 as AIA's engine 3.0.2 holds it, frozen, for activity from 1 July 2025 to 30 June 2026.[^c4] Activity dated before 1 July 2025 has no vintage and is refused.

Each factor file is published here as a signed version, with the attribution its source asks for. The AusLCI values are AusLCI's. AusLCI does not endorse our figures. They are estimates, and we make no claim or comparison on partial life cycle data.

[^c1]: os:0e9c6b45998a78bac973f0833a801a06bd3a746025246d65e5aa8c52c5bbc70d doi:10.5281/zenodo.23490841 sha256:98f6b0d5f41e82c71752031cb178ee858a0922d7f4995c9a6af5b6fc4d15a49a
[^c2]: os:6f16bc06497cae70937aed320598edd690ac447e6899ca26dca8d74c5e0a9899 — file SHA-256 56a1334c4029f94e8ed11a8cd7edcd26cd7ecbc4ffe2cf7af72d7462c37262ab. Values from DCCEEW 2026, Voluntary Emissions Estimation and Reporting Guidelines for Agriculture, Fisheries and Forestry - Methodological Guidance Appendix A, Department of Climate Change, Energy, the Environment and Water, Canberra, March. CC BY 4.0; DCCEEW 2026, Voluntary Emissions Estimation and Reporting Guidelines for Agriculture, Fisheries and Forestry - Methodological Guidance Chapters 5-7 Fertiliser, Agriculture Residue Management, and Rice, Department of Climate Change, Energy, the Environment and Water, Canberra. CC BY 4.0; and DCCEEW 2026, Australian National Greenhouse Accounts Factors, Department of Climate Change, Energy, the Environment and Water, Canberra, August. CC BY 4.0.
[^c3]: os:93a36feb013938b1b0bad75fc4a4ef1c532b22370c19ba56673b0be34a7b70b6 — file SHA-256 1f8626c491539dd0865b0bd337723adf1f51c26518e411e7cc5b85597494a47d. Values from the AusLCI (V48) Carbon Emission Factors (May 2026), © AusLCI, Australian Life Cycle Inventory Database Initiative. AusLCI does not endorse these figures; they are estimates, and any claim made with them is the user's responsibility.
[^c5]: os:69239202c264b458e38452fdef9495c91202a7fbd0db94cfbceed23db7e3a11d — file SHA-256 d25770da2be48aba4e493c87159bb80f80771d446f5f031c6de2a4412fdeac01. Value from AusLCI Lifecycles GHG Emission Intensities for Material Inputs to AUS Ag Fisheries Forestry V48 (March 2026), © AusLCI, Australian Life Cycle Inventory Database Initiative. AusLCI does not endorse these figures; they are estimates, and any claim made with them is the user's responsibility.
[^c4]: os:2329eebcc304ed791451e37576110a16610519117a0673c4546d266e6dda4c15 — file SHA-256 3f30debd161e628b4ccea0d59cbe8f7bde7f5d7f2b6e9f21edb5b08096fa4940. This product incorporates the EAP Calculator Engine open-source code developed and maintained by Agricultural Innovation Australia Ltd. Free access to AIA's open-source code is supported by the Australian Government through funding from the Improving Consistency of On-Farm Emissions Estimates Program. Values read from engine 3.0.2 (GAF release 3.0), CC BY 4.0.