Last week, as part of Climate Action Week Sydney, Chartered Accountants Australia and New Zealand hosted a panel discussion in Sydney on how organisations can implement mandatory climate‑related financial disclosures in a way that is both compliant and decision‑useful.

The session, Climate Disclosures: Aligning Business for Consistent, Decision‑Useful Reporting, brought together perspectives from Samantha Sing Key CA (Grant Thornton Australia), Alex Rudman CA (Stockland) and Mark Robinson (NAB)—spanning sustainability reporting, corporate implementation and banking and capital markets. Held under Chatham House Rules, the discussion reflected practical, on‑the‑ground experience as organisations move into mandatory reporting.

Mandatory climate reporting has already commenced for Group 1 entities, with Group 2 beginning this year and Group 3 following in 2027. In the fourth year of reporting, reasonable assurance across all climate disclosures will be required. This timeline means organisations must start building capability, systems and discipline now.

Different starting points, shared expectations

Organisations are at very different stages of climate reporting maturity. Some are just beginning, while others—particularly large emitting entities, banks and certain other large organisations—have voluntarily integrated climate risk into governance and finance processes for years. AASB S2 Climate-related disclosures (aligned with IFRS S2) recognises these differences, focusing on investor focused, decision‑useful information rather than enforcing uniform processes.

Progress matters more than perfection. What is critical is that organisations understand their business model and their climate‑related risks and opportunities, and how these interact over time.

You probably have more information than you think

Many organisations worry they lack the “right” data. In practice, much of the required information already exists within risk registers, asset management plans and operational processes. The real challenge lies in connecting this information, applying professional judgement and presenting it in a way that meets AASB S2 requirements.

Accountants and finance teams are central to this task.

Scenario analysis: hard, but worth it

Scenario analysis is one of the most challenging aspects of AASB S2, but also one of the most valuable. It tests strategic resilience by exploring how the business may perform under different climate futures. While these conversations can be uncomfortable, they frequently surface insights that would not otherwise emerge.

Judgement and transparency are essential

Climate reporting requires judgement, particularly as data quality and methodologies continue to evolve. AASB S2 expects transparency—clear disclosure of assumptions, methods and limitations. This transparency builds credibility and supports better decision‑making by users.

Minimum compliance still drives real change

Whilst meeting minimum requirements under AASB S2 represents a significant undertaking, reporting is already changing mindsets. For example, organisations are reassessing risks that were previously considered immaterial as longer time horizons are applied.

Climate risk extends beyond the organisation

Climate risk often transfers through supply chains, insurance markets and financial institutions. AASB S2’s focus on the value chain—including Scope 3 emissions where material—is challenging but essential. Understanding where risks lie supports more informed strategic and financial decisions.

Financial impacts: uncomfortable, but indispensable

Assessing anticipated financial effects is one of the most difficult aspects of climate reporting. It challenges traditional notions of materiality and requires organisations to think longer term. This is also where disclosures become truly decision‑useful for investors and other stakeholders.

Assurance is coming—ready or not

Assurance on climate disclosures is already underway. Early engagement with assurance providers and strong documentation of assumptions and sources are critical. Building a solid foundation now will make a material difference as expectations increase.

Why accountants matter more than ever

Accountants and finance teams are central to successful climate reporting. Their expertise in systems, controls, professional judgement and assurance is essential to integrating climate information into core business processes.

From reporting to execution

Climate reporting is not just about compliance—it is about execution. AASB S2 provides a framework for understanding and communicating climate risk, planning for transition and embedding climate considerations into strategy. Starting early and improving over time is far better than waiting for perfect information.

Organisations that act now will be better placed not only to meet regulatory requirements, but to build resilience and long‑term value in a climate‑constrained future.