DCCEEW Releases Final National Climate Scenario Guidance to Standardise Physical Risk Assessments and Support Mandatory Disclosures

Overview

On 16 June 2026, the Australian Government’s Department of Climate Change, Energy, the Environment and Water (DCCEEW) officially released the finalised National Climate Scenario Guidance. This publication establishes the definitive national framework for assessing physical climate risks across Australia and represents the most significant methodological development in climate risk assessment practice since the IPCC Sixth Assessment Report (AR6) was adopted into mainstream professional use. It is the product of extensive public and industry consultation and is aimed squarely at businesses, governments, financial institutions, and environmental practitioners who need a standardised, science-backed approach to climate scenario analysis.

The timing is not incidental. Australia’s mandatory climate-related financial disclosure (CRFD) regime is now active under the Corporations Act 2001 (Cth), as amended by the Treasury Laws Amendment (Financial Market Infrastructure and Other Measures) Act 2024. Large entities classified as Group 1 reporters are already required to disclose physical and transition climate risks under Australian Sustainability Reporting Standard AASB S2. Until the release of this guidance, the industry lacked a nationally consistent methodology to underpin those disclosures. That gap created legal and reputational exposure for listed entities and their advisors alike. The National Climate Scenario Guidance closes it.

For environmental consultants, planners, civil engineers, and their clients, the practical consequence is immediate. Physical risk assessments prepared for development approvals, environmental impact statements, infrastructure design, and property transactions must now be measured against this framework. Assessments that cannot demonstrate alignment with the guidance’s prescribed emissions pathways and climate model selection approach will increasingly be regarded as deficient, whether by regulators, financiers, or the courts. This is not a voluntary best-practice document. It is the baseline.

Key details of the National Climate Scenario Guidance methodology

The National Climate Scenario Guidance is structured around a tiered decision-making framework that requires practitioners to select global warming levels (GWLs) and emissions pathways using multiple Shared Socioeconomic Pathways (SSPs) drawn from the IPCC AR6. The guidance specifically urges the use of more than one SSP to stress-test asset resilience across a range of futures, rather than anchoring analysis to a single pathway. This replaces older modelling conventions, many of which relied on Representative Concentration Pathways (RCPs) from the IPCC Fifth Assessment Report, which are now regarded as insufficiently granular for site-specific and infrastructure-scale assessments in the Australian context.

The guidance distinguishes clearly between two categories of physical hazard. Acute hazards include extreme rainfall events, bushfire, cyclones, and storm surge, all of which are characterised by discrete occurrence and often short duration but high consequence. Chronic hazards include sea-level rise, shifts in average temperature, extended drought periods, and changes to seasonal rainfall patterns, which accumulate over decadal timeframes and affect asset functionality and value progressively. Practitioners are required to evaluate both hazard categories using downscaled climate datasets that reflect regional conditions rather than global averages, which is a methodologically important distinction for a geographically and climatically diverse country like Australia.

A critical integration point is the guidance’s alignment with Australian Rainfall and Runoff (ARR 2019), specifically Book 1, Chapter 6, which covers climate change considerations in flood estimation. ARR 2019 requires variable climate change factors to be applied to design flood levels rather than the fixed percentage adjustments that were common practice under earlier versions of the guidelines. The National Climate Scenario Guidance provides the emissions pathway and GWL inputs that feed into those variable factors. This means stormwater management strategies, flood studies, and drainage designs that do not reference both documents simultaneously are now methodologically incomplete.

For entities subject to AASB S2, the link between the guidance and mandatory disclosure obligations is explicit. AASB S2 requires disclosure of the climate scenarios used, the time horizons assessed, and the physical risks identified. The National Climate Scenario Guidance defines the acceptable methodology for scenario selection. An entity that cannot demonstrate its physical risk assessment was conducted using appropriate SSPs and downscaled regional data will face scrutiny from auditors, the Australian Securities and Investments Commission (ASIC), and potentially institutional investors who are themselves subject to fiduciary obligations to understand the physical risk profile of their holdings.

Australian context: alignment with existing frameworks and state-level practice

Australia’s regulatory environment for physical climate risk assessment has, until now, been fragmented. State environment protection authorities, planning departments, and infrastructure agencies have each applied their own guidance, often referencing different climate projections, different time horizons, and different emissions scenarios. New South Wales planning policy has referenced the State Government’s NSW Climate Change Policy Framework. Queensland has drawn on Queensland Future Climate projections. Victoria has operated under its own Climate Change Act 2017 obligations. South Australia has referenced CSIRO projections embedded in its coastal planning policies. The result has been that a multi-jurisdictional development or portfolio assessment could involve three or four different methodological frameworks operating simultaneously, creating inconsistency in risk outputs and complicating comparison across assets and regions.

References and related sources

• Primary source: www.dcceew.gov.au
• listcorp.com
• aicd.com.au
• igcc.org.au
• actuaries.asn.au

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This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

Published: 23 Jun 2026

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