This study examines whether equity investors value climate transition disclosures during a period of regulatory transition in Australia. Using a sample of ASX 100 firms from 2020 to 2023, the study analyses the association between firm value, carbon emissions, and climate transition–related disclosures. Our study confirms that carbon emissions are negatively associated with firm value in Australia during the sample period, indicating that Australian investors price emissions exposure as a financial liability. The study then examines whether climate transition disclosure provides incremental value-relevant information beyond emissions. At the aggregate level, overall transition disclosure is not associated with firm value. However, disaggregated analysis reveals substantial heterogeneity across disclosure types. Climate Ambition disclosures are positively associated with firm value, while Transition Preparedness disclosures are negatively associated with firm value. Transition Control disclosures do not exhibit an overall association with firm value, although further disaggregation indicates offsetting effects across governance, performance, and reporting quality components. Cross-sectional analyses show that these valuation patterns vary with industry exposure and firms’ emissions profiles. Overall, the findings indicate that investors differentiate across types of climate transition disclosure rather than valuing disclosure quantity per se. The results highlight the importance of disaggregating climate disclosure measures and provide evidence relevant to the design and interpretation of climate-related financial disclosure during the transition from voluntary to mandatory reporting regimes.