For many Australian businesses, the biggest challenge in emissions reporting is not measuring what happens inside their own operations. It is understanding what happens across the value chain.
Scope 3 emissions can represent a significant share of an organisation’s overall greenhouse gas footprint, but the data behind them is often less mature than the information available for Scope 1 and Scope 2.
AASB S2 now requires Scope 3 disclosure. Group 1 entities with a December year-end are already in their first year of mandatory Scope 3 reporting, and Group 2 entities began reporting from 1 July 2026. That gap can no longer be ignored.
The businesses handling this well have recognised something important: Scope 3 isn’t a calculation problem. It’s a data supply chain problem – and it needs to be managed with the same discipline as financial data.
The data sits outside the business
Scope 1 and 2 emissions come from activities a business directly controls. Scope 3 doesn’t. It spans 15 categories, including purchased goods and services, capital goods, transportation, fuel and energy-related activities, employee commuting, business travel and the processing, use or disposal of products.
The information required to calculate these emissions can therefore sit across procurement systems, suppliers, invoices, financial records and other parts of the business.
For companies managing large operations or complex supply chains, bringing this information together can quickly become a significant reporting exercise.
The challenge is particularly acute in Western Australia. For resources, mining services and energy businesses, purchased goods and services and the use of sold products can far outweigh operational emissions – and the data for both sits largely with suppliers and customers. Many companies have historically relied on spreadsheets, estimates or one-off calculations to fill the gaps.
That may provide a starting point, but it can become difficult to maintain when the same data needs to be updated, reviewed and ultimately supported by evidence.
The challenge is not simply getting a number
There is a tendency to view Scope 3 reporting as a calculation problem. In practice, it is a governance challenge involving data provenance, calculations and assurance.
Businesses need to understand where their data comes from, which emission factors have been applied, what assumptions have been made and how those calculations can be reproduced from one reporting period to the next.
“Scope 3 should not be treated as another compliance exercise. Its real value is exposing the transition risks sitting latent in your value chain – and you can’t manage what you haven’t measured,” says Greenbase Sustainability and Climate Manager Fraser Eynon.
This becomes particularly important as climate-related disclosures receive greater scrutiny each year. ASIC has begun reviewing the first mandatory sustainability reports, and assurance requirements will extend further as the regime phases in.
The objective does not need to be perfect Scope 3 data from day one. A more practical approach is to establish a consistent, structured and transparent methodology, then improve the quality of the underlying data over time.
Turning Scope 3 into a manageable process
For businesses, the next step is moving Scope 3 away from an annual exercise and towards a structured, continuous process of data collection, evaluation and reporting.
That means establishing clear boundaries, identifying the materiality of the 15 categories, standardising data collection, documenting assumptions and creating a clear audit trail from the original activity data through to the reported emissions figure.
In Greenbase’s experience, the businesses that cope best treat Scope 3 like financial data, with every figure traceable to its source. That thinking underpins Greenbase’s Envago sustainability reporting platform, which brings Scope 3 data into the same reporting environment as other emissions and sustainability information.
Rather than treating Scope 3 as a separate spreadsheet exercise, businesses can capture activity data, emission factors, data sources and calculation methodologies within a structured system.
This creates greater visibility over how emissions figures have been developed and provides the audit trail required for review and assurance.
Building for better data over time
A practical Scope 3 system also needs to accommodate different levels of data maturity. Not every supplier will provide detailed emissions information, and not every organisation will have the systems needed to collect it immediately.
A reporting framework can therefore start with reasonable estimates and progressively incorporate better information as it becomes available.
This approach allows businesses to improve their Scope 3 inventory without having to rebuild their reporting process each year. It also creates an opportunity to use the same underlying data for more than compliance.
Once businesses have greater visibility over their value-chain emissions, the information can support procurement decisions, supplier engagement, emissions reduction planning and broader sustainability strategies.
From reporting requirement to business insight
The growing focus on Scope 3 is changing the way businesses need to think about emissions data. The question is no longer simply how to calculate a Scope 3 figure for an annual disclosure.
It is how to establish a reporting process that is consistent, transparent and capable of improving as the quality of business and supplier data improves.
For businesses preparing for increasingly detailed climate disclosures, those that treat Scope 3 as a data supply chain problem and not as an annual calculation problem will be best placed not just to report emissions, but to eventually reduce them.
How Greenbase can help
Whether you are establishing your Scope 3 inventory or looking to strengthen your existing reporting processes, Envago can help create a more consistent and transparent approach to emissions data.
Envago helps businesses bring sustainability data, calculations and reporting into a more structured environment – supporting the move from fragmented spreadsheets and estimates towards more consistent, traceable and reviewable data.
Contact Greenbase to learn more or book a free demo.
