Boredom Central - I built an open, version-controlled emission factor dataset aligned to IPCC AR6 GWP-100

I was building GreenCalculus (carbon accounting/calculator platform — disclosure: it’s my project) and kept running into the same problem:

There’s no single clean, open, version-controlled emission factor dataset aligned to IPCC AR6 GWP-100.

The data exists, but it’s scattered across:

…with different units, different GWP vintages, and almost no visibility into what changed between versions.

So I consolidated it into one open repo:

Everything is free, public, and downloadable. No signup, no API key.

What’s inside:

gwp-values.json AR6 + AR5 values side-by-side for 16 greenhouse gases.
emission-factors.json + .csv Scope 1 fuel combustion + Scope 2 electricity grid factors across 15 countries.
METHODOLOGY.md Full calculation methodology with formulas + source references.
CITATION.cff Makes it easy to cite in BibTeX / APA.

One thing I think carbon accounting software gets wrong:

Emission factors should behave like versioned code dependencies.

If a methane GWP changes, you should be able to diff it, trace it, and reproduce historical outputs exactly.

Git is honestly a better audit trail than most ESG software I’ve seen.

Interesting migration issue I noticed while compiling this:

A lot of inventories still use older methane GWPs.

So moving from AR4 → AR6 increases fossil methane impact by ~19% using the exact same activity data.

Even AR5 → AR6 is still about +6%.

PRs/corrections are genuinely welcome.

And if you just want to calculate emissions instead of building your own model:

Happy to answer methodology questions or discuss factor provenance/versioning.

I Built An Open, Version-controlled Emission Factor Dataset Aligned To IPCC AR6 GWP-100 — Free To Use And Cite