For enterprise & compliance
Audit-ready GHG inventories, built to survive assurance
If your Scope 1+2 numbers are heading for a third-party assurance review, the question isn't whether they look right — it's whether every factor in them can be traced back to a source when an assurer asks. I build greenhouse gas inventories the way an auditor would want to receive them: each emission factor documented, each multiplication step legible, and a provenance pack you keep. I'm assuming you're preparing for mandatory disclosure rather than a voluntary report; if the driver is different, tell me and I'll adjust the framing.
Why now
The reporting calendar is what makes this urgent. Under Source · hover or focusCalifornia SB 253 (Climate Corporate Data Accountability Act) applies to companies above $1B in revenue doing business in California; the first Scope 1+2 disclosures are due in 2026, with third-party assurance phasing in from 2027.. An inventory assembled quickly to hit a deadline and an inventory built to withstand assurance are not the same artifact — and the gap between them is exactly what a reviewer is paid to find. I can't tell you whether your specific filing is in scope; that's a determination for your counsel. What I can do is make sure that whatever you file has a defensible audit trail underneath it.
What you get · Fixed price
Productized offers
Fixed scope, a defined deliverable, and a price you can see before we talk. These are the offers that map most directly onto a compliance timeline; the full Services page lists the rest.
GHG Inventory Starter Pack
4 weeks $24–40KA Scope 1+2 inventory with a full provenance pack — every factor traceable to its source, built for third-party assurance — for a company facing a reporting deadline.
Methodology Audit
2 weeks $9–15KA line-by-line review of an existing inventory methodology, codebase, or model — what is defensible, what is not, and what to fix first — for a team that needs to know where it stands before an assurer does.
Independent Replication
4–8 weeks quotedYour inventory rebuilt from the data up by someone with no stake in the original — for when a number matters enough to need an outside check before it's filed.
Spatial Brief
2 weeks $9–15KOne well-defined geospatial question answered with publication-quality maps and a findings memo — useful when a facility-level or site-boundary question sits underneath your emissions accounting.
Why it holds up
Provenance is the audit trail
The multiplication chain is the evidence
A GHG number is activity data times an emission factor, repeated across every source. When an assurer traces a figure, they're walking that chain backward: which factor, from which published set, which version, applied to which activity total, from which record. If any link is undocumented, the whole line is a finding. I build the chain to be walked backward from the start — so review is confirmation, not archaeology.
Every factor traceable — deliverables you own
Each emission factor in the inventory is pinned to its source and version, not to my say-so. You get the workbook, the calculation logic, and the provenance pack as runnable artifacts you own outright — built on open-source tools, so nothing depends on renewing a license with me to keep using what you paid for. If your assurer wants a different factor set or a methodology note rewritten, you can act on it without waiting on a vendor.
Who's behind it
The work is senior-led — I'm the one on the keys. My background is a PhD in civil systems engineering and 16 published works, with GHG accounting experience spanning retail, aerospace, logistics, finance, and water, including multinationals with collective emissions over 500,000 tCO₂e. The method behind the provenance discipline is a published one. Full publication record on ResearchGate ↗.
Bring me the deadline
Tell me the filing you're preparing for and where your inventory stands today. I'll tell you honestly whether a four-week starter pack fits your window or whether you need something else first — including whether you need me at all.