Glossary›Emissions accounting and measurement›Scope 1 emissions
Glossary term
Cluster D · D1
Tier 1
Scope 1 emissions
Definition
Scope 1 emissions are direct greenhouse gas emissions from sources an organisation owns or controls. They include fuel burned in company vehicles and equipment, natural gas combusted on site, emissions released by industrial processes, and refrigerant and other gases that leak from owned plant. They are the only emissions an organisation releases itself.
· paragraph 29(a)(i)(1), Appendix D definition · in force from each entity’s first reporting period
On this page
In practice
Scope 1 is the smallest of the three scopes for most Australian service businesses and the largest for manufacturing, transport, agriculture and resources. It is also the scope that gets assured first, in every entity’s first reporting year, which makes it the one where a first-time reporter’s evidence discipline is tested before anything else.
Four source types make up almost every Australian Scope 1 inventory, and they fail in four different ways.
Source type
What it covers
How it fails
Stationary combustion
Gas, diesel or LPG burned in boilers, furnaces, ovens and generators. The data is usually clean because it arrives on a retailer invoice.
Period. A gas bill cycle almost never aligns to 30 June, and an entity that takes twelve bills without apportioning the straddling ones has a cut-off error in a figure that was otherwise perfect.
Mobile combustion
Fuel burned in owned or leased vehicles, forklifts, plant and marine or air craft.
The unit. A fuel card statement in litres is measured data. Fuel expense in dollars converted at an assumed price per litre is an estimate, and the assumed price is a judgement that has to be documented. Entities routinely present the second as though it were the first.
Process emissions
Released by chemical or physical transformation rather than combustion: cement clinker, lime, aluminium smelting, some chemical manufacture.
Few captured entities have them; those that do usually have an NGER history and a method already.
Fugitive emissions
Leaks and releases: refrigerant from air conditioning and cold chain, methane from landfill and wastewater, SF6 from switchgear.
The single most under-reported Scope 1 source in Australia, and the reason is structural. There is no invoice for a leak. The activity data is the quantity of refrigerant recharged into equipment during the year, which lives in service contractor invoices, not in any system the finance team touches.
The judgement that decides the size of the whole number is not in any of those four. It is the organisational boundary. Under operational control (the dominant Australian approach) a leased site the entity operates is fully inside Scope 1 and a joint venture it does not operate is fully outside. Change the approach and the same physical assets move in or out wholesale. The boundary is decided once, disclosed, and applied consistently; it is not revisited because the answer is inconvenient.
One thing Scope 1 is not, and this catches boards. It is not “our emissions” in any complete sense. For most captured entities Scope 1 is a minority of the total and often a small one. An entity reporting a falling Scope 1 while its Scope 3 rises has not decarbonised; it has usually outsourced.
What the assurer does with it
Scope 1 attracts limited assurance from each entity’s first reporting year under ASSA 5010 paragraph 10, alongside Scope 2. The assurer’s work runs completeness first, accuracy second, and the order matters because completeness is the assertion that cannot be fixed by explanation.
The first request is a population, not a number: every site, every meter, every vehicle, every fuel account, agreed to something in the finance system. They build an independent population from the asset register, the lease schedule, the property listing and the fleet register, and they compare it to the inventory line by line. A site in the lease schedule that is absent from the inventory is a direct finding.
The second procedure is the general ledger bridge. Fuel expense for the year, less non-fuel items coded to the same account, divided by an average price per litre, compared to the litres in the inventory, with the residual explained. They re-perform the bridge and test the reconciling items. A bridge that explains most of the balance and names what it cannot explain is far stronger evidence than an unbridged figure, and entities consistently underestimate how much weight the assurer puts on it.
Then accuracy: a sample of source documents vouched to the inventory, quantities and periods agreed, factors recalculated against the cited edition of the factor set.
They accept an externally generated source document naming the reporting entity, the quantity and the period, tied to a line in the inventory. They reject a fuel volume derived from dollars with no documented price assumption, a refrigerant figure based on system nameplate capacity rather than recharge records, a site listing certified complete by management with no independent corroboration, and any factor applied without a cited source edition.
The single most common first-year finding is not arithmetic. It is a site, a subsidiary or a vehicle class that is inside the financial consolidation and outside the emissions inventory, with nothing written down explaining why.
Commonly confused with
Scope 2. Gas burned in your own boiler is Scope 1; electricity generated at a power station and consumed by you is Scope 2. The test is where the combustion physically happened and whether you controlled the source. Also confused with “emissions we are responsible for”, which is a moral framing rather than an accounting one: responsibility under AASB S2 extends across all three scopes.
Timing and relief
No relief. Scope 1 is disclosed and assured from the first annual reporting period. The only Appendix C relief that touches it is paragraph C4(a): an entity that used a non-GHG Protocol measurement method in the period immediately preceding its first application of the standard may continue using that method in its first period, and under paragraph C5 may keep relying on it when presenting that period as comparative information later. For an NGER reporter, that other method is the NGER Measurement Determination.
Sources
1
2
Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard (2004 revised edition)
GHG Protocol
3
ASSA 5010 Timeline for Audits and Reviews of Information in Sustainability Reports under the Corporations Act 2001
AUASB
Review status
Review required
Last reviewed
15 September 2026
Editorial pass, unsigned
Reviewer required
Carbon accounting specialist and registered company auditor
Next scheduled review
1 August 2027
next expected National Greenhouse Accounts Factors release
Part of
Cluster D, Emissions accounting and measurement
49 terms from the head term carbon accounting down to individual Scope 3 categories and the mechanics of factors, boundaries and data quality. The largest cluster in the glossary.
Related terms
The indirect half of the pair assured alongside Scope 1 from year one
The judgement that decides which sites and entities are inside Scope 1 at all
The dominant Australian boundary approach and what it pulls in
Related questions
What evidence do we need for each emissions number?
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Every reported number needs a source document you did not create for the report, the activity data drawn from it, the emission factor and its published edition, and the calculation joining them. Fleet fuel needs litres from fuel card statements, electricity needs kWh by site from retailer invoices with the matching state factor, and refrigerants need kilograms by gas type from service records.
What is our organisational boundary and who decides it?
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Your organisational boundary is the set of entities and facilities whose emissions you report, and the basis on which you include them. Management decides it, the board or audit committee approves it, and it should reconcile to the consolidated entity in your financial report. Operational control is the common Australian starting point, and the friction sits in joint ventures, leased sites, franchises and recent acquisitions.
What will our auditor actually ask for?
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In year one they ask for evidence behind the disclosures that are actually assured: Scope 1 and Scope 2 emissions, your governance disclosures, and the specified strategy paragraphs on climate risks and opportunities. In practice that means source documents, a calculation they can rebuild from those documents, and minutes showing the governance you described actually happened.
Other terms in this cluster
Scope 1 emissions