Multi-Framework Carbon Reporting from One Dataset: NGER, AASB S2, CDP, GRI, GHG Protocol

A sustainability manager at an ASX-listed property company told us she maintains five separate spreadsheets. One for NGER. One for the company's GRI sustainability report. One for CDP. One that's formatted for GHG Protocol alignment. And now a fifth for AASB S2, because Group 1 mandatory reporting kicked in for financial years starting 1 January 2025.

Five spreadsheets. Same underlying emissions data. Different cuts, different formatting, slightly different methodological choices. And every time someone updates one sheet, the others fall behind. By October — when NGER is due and CDP scores are being finalised and the board wants a draft AASB S2 disclosure — the numbers across those five files have drifted apart. Not by much. But enough that an auditor notices.

We've spent two decades inside enterprise data systems at mining and energy companies. The idea that you'd maintain five separate copies of the same core dataset, manually reformatted for five different consumers, would get you laughed out of any data engineering standup. But that's exactly what most Australian companies do for multi-framework carbon reporting.

It doesn't have to work this way.

The frameworks want different views of the same data

Here's what's actually going on. The GHG Protocol Corporate Standard sits underneath almost everything. It defines how you draw your organisational boundary, how you classify Scope 1, 2, and 3, how you calculate emissions using activity data and emission factors. CDP explicitly requires companies to use GHG Protocol methodology. AASB S2 paragraph 29(a) references it directly. GRI 305 (Emissions) is built on GHG Protocol. NGER uses a slightly different methodology defined in the NGER Measurement Determination, but the underlying activity data — fuel consumed, electricity purchased, refrigerant lost — is the same.

So the raw data doesn't change. What changes is how each framework wants it sliced, labelled, and presented.

NGER wants facility-level emissions broken out by gas type (CO2, CH4, N2O, HFCs, PFCs, SF6, NF3), by scope, by ANZSIC code, submitted electronically through the EERS system by 31 October. It uses AR5 Global Warming Potential values as mandated by the Measurement Determination.

AASB S2 wants your emissions disclosed within a four-pillar structure — Governance, Strategy, Risk Management, Metrics & Targets — with both location-based and (optionally) market-based Scope 2, industry-based intensity metrics, and your seven constituent greenhouse gases converted to CO2-e. It technically requires AR6 GWP values, though the AASB S2025-1 amendments now provide jurisdictional relief so NGER reporters don't have to recalculate everything twice.

CDP wants investor-focused climate data across 13 modules, aligned with ISSB/IFRS S2 since the 2024 questionnaire restructure. It scores you on completeness, action, and verification. The response window opens mid-June and closes late October — right on top of NGER deadline season.

GRI 305 wants Scope 1, 2, and 3 in metric tonnes of CO2-e, plus biogenic CO2 separately, plus emissions intensity ratios. But GRI's materiality model is fundamentally different from AASB S2. GRI uses impact materiality — how your company affects the environment — while AASB S2 uses financial materiality — how climate affects your company's value. Same emissions data, different reason for disclosing it.

The point is: one well-structured emissions dataset, with facility-level granularity, per-gas breakdowns, both AR5 and AR6 GWP conversions, and location-based plus market-based Scope 2 calculations, can feed all of these. The dataset doesn't need to be rebuilt for each framework. The report templates do.

Where the numbers actually diverge (and it's less than you'd think)

The biggest technical divergence between frameworks is the AR5/AR6 GWP issue. NGER uses AR5 values: methane at 28 (biogenic) or 30 (fugitive), N2O at 265. If AASB S2 required AR6 — methane at 27.0 (biogenic, but fossil methane jumps to 29.8 with climate-carbon feedback) and N2O at 273 — you'd need two parallel calculations for every emission source.

Until December 2025, this was a genuine headache. Then the AASB approved AASB S2025-1, which grants jurisdictional relief. If you're required to report under NGER, you can use AR5 GWP values in your AASB S2 disclosure for the portion of your organisation covered by NGER. You don't have to recalculate. That's a significant simplification.

But the relief only applies to the part of your business that's subject to NGER. If you have overseas operations or facilities that fall below NGER thresholds, those emissions technically need AR6. So we store both sets of GWP values. For most domestic-only reporters, the difference is now moot. For multinationals, it still matters.

The other divergence is Scope 2 methodology. NGER has traditionally been location-based only, though a voluntary market-based method has been available since 2023-24, with state-level Residual Mix Factors introduced for 2025-26. AASB S2 paragraph 29(a)(v) requires location-based Scope 2 as the primary method, with market-based available as a supplementary disclosure. CDP wants both, and will penalise you if you only provide one. GRI 305-2 also asks for both.

In Carbonly, we track location-based and market-based Scope 2 as separate parallel calculations from the moment electricity data enters the system. The same kWh figure generates two emissions numbers — one using the NGA Factors 2025 state-based grid factors (NSW 0.64, VIC 0.78, SA 0.22 kg CO2-e/kWh), and one using the national Residual Mix Factor of 0.81 for any uncovered consumption. Every report template pulls whichever method that specific framework requires.

What a single-dataset approach actually looks like

We built Carbonly's report generation to work from one emissions dataset across six report templates: NGER, GHG Protocol, CDP, TCFD, GRI, and AASB S2. Plus custom templates for companies that need something specific for their board or supply chain partners. Here's how it works in practice.

Every utility bill, fuel receipt, refrigerant log, or travel expense that enters the system goes through our 7-phase AI processing pipeline. It gets classified, extracted, validated, normalised, and converted into emissions using NGA emission factors. The output lands in a single facility-level emissions ledger with full audit trail — every number traced back to its source document, emission factor, and calculation method.

That ledger stores emissions at the granularity needed to serve any framework: per-facility, per-gas, per-scope, per-reporting-period. Both AR5 and AR6 conversions. Both location-based and market-based Scope 2. All 15 Scope 3 categories where data exists.

When you generate a report, you pick a template. The NGER template pulls facility-level data structured for EERS submission — emissions by gas, by scope, energy production and consumption, method statements. The AASB S2 template organises the quantitative Metrics & Targets pillar (paragraphs 28-37), including cross-industry metrics, Scope 1/2/3 disclosures, and target tracking. The CDP template maps data into Module 7's climate performance structure. The GRI template formats emissions per GRI 305-1 through 305-5, including biogenic CO2 and intensity ratios. GHG Protocol format produces a standard corporate inventory.

Each template applies the specific formatting, categorisation, and methodological choices that framework requires. But the underlying numbers come from one place.

You can export as PDF, Excel, or CSV. You can schedule reports to generate automatically — useful when you've got an October NGER deadline and a CDP submission window overlapping.

What doesn't auto-populate (honesty section)

I'd be lying if I said software generates a complete report for every framework. It doesn't. And anyone who tells you otherwise is selling something you'll regret buying.

The quantitative sections — your actual emissions numbers, energy data, intensity metrics, target tracking — those come directly from the dataset. That's maybe 40% of an AASB S2 report and 60-70% of a CDP climate response. The rest is qualitative.

AASB S2's Governance pillar (paragraphs 5-12) asks about your board's oversight structure, management roles, competency, and how climate feeds into remuneration. No software can write that for you. Strategy (paragraphs 13-22) requires scenario analysis narratives and transition plan descriptions. Risk Management (paragraphs 25-27) describes your processes for identifying and prioritising climate risks. These sections need human input.

CDP's questionnaire changes every year. In 2026, they're adding an Oceans module and expanding forest commodity scoring to include cocoa, coffee, and rubber. The structural changes mean that even well-automated CDP responses need manual review against the current questionnaire. We update our CDP template annually when the new questionnaire drops (usually late April), but there's always a window where new questions need fresh answers.

GRI's materiality assessment is its own exercise. Because GRI uses impact materiality — "how do we affect the world?" rather than AASB S2's financial materiality — the scope of what's material can be completely different. A topic might be material under GRI but immaterial under AASB S2, or vice versa. The emissions data might be the same, but the framing, context, and narrative around it aren't.

We're honest about this split. Software handles the data. Humans handle the story. The value of single-dataset reporting is that you're not re-entering numbers and introducing transcription errors across five spreadsheets. Not that you skip the thinking.

The real cost of separate spreadsheets

KPMG's 2024 Sustainability Reporting Survey found that 76% of ASX100 companies were already reporting aligned with TCFD, 90% had set carbon targets, and 37% had SBTi-aligned targets. That's a lot of reporting. And for the 961 NGER-registered controlling corporations — all of whom are automatically pulled into ASRS Group 2 if they aren't already Group 1 — the framework count is about to jump.

Consider a mid-sized resources company that reports under NGER (because it exceeds the 50kt corporate threshold), is now in ASRS Group 2 (because NGER reporters are automatically captured via the registration pathway), gets a CDP request from its largest customer, and publishes a GRI-aligned sustainability report because its investors expect it.

That's four frameworks. If each report is built from scratch — separate data pulls, separate formatting, separate QA — you're looking at roughly 8-12 weeks of work across the year just for reporting. At consultant rates of $250-$400/hr, that's $80,000-$150,000 annually. And the worst part isn't the cost. It's the risk that the numbers disagree.

When your NGER submission says 47,200 tonnes and your CDP response says 48,100 — because someone used a different reporting period boundary, or forgot to update the electricity factor after switching from the 2024 NGA Factors to the 2025 edition, or double-counted a facility that changed ownership mid-year — you've got a reconciliation problem. Your auditor will flag it under ASSA 5010. The CER's data analytics might catch it. And if your CDP score gets published alongside an AASB S2 disclosure that shows different numbers, you've got an ACCC exposure issue on top of everything else.

One dataset eliminates this. Not because the reports are identical — they shouldn't be, because the frameworks ask different questions — but because every quantitative figure traces back to the same source.

Framework convergence is real but incomplete

There's a popular narrative that the frameworks are converging and we'll eventually have one global standard. That's half right. TCFD disbanded in October 2023 — it's fully absorbed into ISSB/AASB S2. The ISSB granted GHG emissions equivalence to the new GRI 102 in mid-2025, meaning a single set of emissions disclosures can satisfy both. CDP restructured around ISSB alignment. GHG Protocol sits at the methodological foundation of all of them.

But "converging" doesn't mean "identical." NGER is a regulatory compliance scheme with its own legislation, its own measurement determination, its own reporting format, and its own enforcement body (the Clean Energy Regulator). It isn't going away just because AASB S2 exists — in fact, being an NGER reporter now pulls you into mandatory ASRS reporting. GRI remains the go-to framework for double materiality and stakeholder-focused reporting, which AASB S2 explicitly doesn't cover. CDP adds the investor-requestor dynamic and the scoring mechanism that no other framework replicates.

So while the data requirements are converging, the report outputs stay distinct. That's exactly why a single-dataset, multi-template approach makes sense. You're not trying to force five frameworks into one report. You're feeding five different report generators from one verified dataset.

We don't think the framework count is going down any time soon. If anything, TNFD (nature-related disclosures) and the EU's CSRD are adding to the pile for Australian companies with European exposure. The answer isn't fewer frameworks — it's better data architecture underneath them.

Start with your NGER data and build outward

If you're an NGER reporter, you already have the most granular dataset of the lot. Facility-level, per-gas, method-specific emissions with energy production and consumption. That's more detail than any other framework demands. AASB S2 needs less granularity (entity-level, not facility-level, though your auditor will want to see the facility breakdown). CDP needs different granularity (sector-specific questions, verification status, reduction targets). GRI needs different framing (impact materiality context).

The practical move is this: get your NGER data right first. Make sure every facility's emissions are calculated from source documents with a full audit trail. Store both AR5 and AR6 conversions. Track location-based and market-based Scope 2 from day one. Then let report templates do the reformatting.

If you're building five spreadsheets for five frameworks, you're not doing five times the work. You're doing five times the risk.

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