Docs / What was changed in each source

Changes to Stepwise 2006

Part of What was changed in each source. What is still open about Stepwise 2006 is on the issue tracker under the label stepwise.

Stepwise 2006 arrives as a SimaPro method file, Stepwise2006_v1.09.csv, so its flows are the rows its characterisation factors name: 6,064 of them, of which 6,055 are merged and nine are refused (listed at the end of this page). It is merged last, after ecoinvent 3.12, ecoinvent 3.8 and BAFU 2026 v1, on the build of 2026-08-29 from commit 54b0f9d.

The file ships no identifier of any kind. Every row on this page is therefore named the way the method file writes it — name, compartment and sub-compartment, unit — and that is how to find it in the CSV. The uuids this project gives Stepwise rows are derived from those same fields and are not quoted here.

Corrections to the file's own rows are in stepwise-2006-manual-fixes.json. Because Stepwise inherits ecoinvent 2's spellings and ecoinvent 2's data habits, it also receives every correction in simapro-lineage-manual-fixes.json, which is applied to each SimaPro-shaped list. Thirteen rows are sent to a chosen target by stepwise-2006-match-overrides.json, twelve of them because a kilogram or a cubic metre of a fuel has to land on a flow EF 3.1 accounts in megajoules.

In one line: two registry numbers were corrected (one removed, one replaced), no ionic charge was added, 51 rows were merged into 14 consensus flows, and no name was split across two substances.

One name, two substances

None. On the 2026-08-29 build no Stepwise name reaches two consensus substances. That is what a method file should do: it carries one row per name per compartment, with one registry number for the name wherever it appears, so there is nothing on a row for the merge to read differently from one compartment to the next.

An ionic charge was added or corrected

None. Stepwise writes a charge wherever it means an ion, in the SimaPro spelling: Chromium III and Chromium VI, six rows each, are published as Chromium(3+) and Chromium(6+), which is the same charge in the consensus list's notation. Ammonium, ion (six rows, CAS 14798-03-9) is published as Ammonium; the ion is what the name and the CAS number both say, and the consensus name leaves the word off because ammonium is only ever an ion.

Rows merged into one flow

Fifty-one Stepwise rows land on fourteen consensus flows, so a reader who follows one of those flows back to the method file finds more than one row there. Every case is one of four kinds.

A plain row beside its qualified twin

Stepwise ships four carbon dioxide rows into unspecified air, all carrying 124-38-9: Carbon dioxide, fossil, Carbon dioxide, biogenic, Carbon dioxide, land transformation, and a bare Carbon dioxide. The method itself says what the bare row is: it is characterised at 1.0 under Global warming, fossil and under nothing else, exactly like the fossil row. So the bare row is sent to the fossil substance by stepwise-2006-match-overrides.json (#811), and the two rows are one flow.

Two spellings of one substance

A fuel by mass and by energy

EF 3.1 accounts fossil fuels and uranium as resources by their energy content, in megajoules, because that is what the Resource use, fossils indicator counts. Stepwise ships each of these fuels twice — once as an energy row, in MJ, which lands directly, and once as a mass row, in kg, which stepwise-2006-match-overrides.json sends onto the same flow with a conversion factor. The factor used is always Stepwise's own: the method file states a higher heating value for the substance and states a Non-renewable energy factor for the row, and for every fuel but natural gas the two agree (#805).

These are gross (higher) heating values, which is why they sit above the 18.01, 9.41 and 43.4 MJ/kg that ecoinvent's and BAFU's kilograms of the same fuels take onto the same flows. Stepwise's own lower heating values — 8.75 for brown coal, 43.2 for crude oil — sit among the other lists' numbers, so the gap is the basis and not a disagreement about the fuel.

Natural gas is seven rows, and six of them state their own energy content in their name:

All seven are published as Natural Gas, Resource → Ground, in MJ.

Uranium is four rows in Raw / (unspecified), all in kilograms and all carrying 7440-61-1, and all four land on Uranium, Resource → Ground, in MJ. One is the plain Uranium row, sent there by the overrides at 560,000 MJ/kg — the gross fission energy content of natural uranium, the CAS number ecoinvent's and BAFU's uranium rows already take onto this flow. The other three are the rows whose names state their own value, and those are rebased by simapro-lineage-manual-fixes.json before the merge reads them: the unit is changed from kg to MJ at the factor the name states, and the name is then shortened to Uranium so the row reaches the substance (the original spelling is kept as a synonym).

Every one of these is fission energy content, never a heating value.

An ore grade in the name

Stepwise inherits ecoinvent 2's habit of writing the grade of the deposit into a resource flow's name: Copper, 0.52% in sulfide, Cu 0.27% and Mo 8.2E-3% in crude ore. The grade is a property of the mine and says nothing about what the metal is; every such row carries the metal's own registry number, and so lands on the metal.

Nine rows that are refused

These rows are in the method file and are neither merged nor published. They are recorded in stepwise-2006-additional-flows.json so that their absence is a decision and not an oversight.

Registry numbers corrected

Two, both before anything reads the row — and a third entry in the lineage file that Stepwise happens not to trigger.

The lineage file also renames one Stepwise row without touching its CAS number: Carbon dioxide, in air (Raw / (unspecified), kg, 124-38-9) becomes Carbon dioxide, biogenic, in air. Carbon dioxide taken from the air is what growing biomass takes up, and this is where ecoinvent's row of exactly this name goes through its own correspondence table and where BAFU's three rows are sent. Without the word the CAS number reaches all nine carbon dioxides at once; with it the row lands on Carbon Dioxide (biogenic), Resource → Air. The vendor's spelling is kept as a synonym.