Carbon emissions make a significant contribution to climate change and global warming. The accounting standards, though, are silent on the treatment for carbon emissions and disclosures. As a result, stakeholders, other than the Australian Government, are reliant on voluntarily disclosed carbon emission information. This thesis investigates voluntary carbon emission disclosure practices of firms set within a carbon-based economy, Australia. Specially, this thesis notes the changes in voluntary carbon emission disclosures over time, prior to the introduction of the National Greenhouse and Energy Reporting (NGER) Act 2007 to post-legislation, 2005 to 2011. In addition, this thesis also investigates the determinants of such disclosures.
A multi-theoretical framework incorporating legitimacy, signalling and institutional theories support this thesis. The sample comprises of hand-collected and manually-coded data from 170 Australian Securities Exchange (ASX) listed firms with 85 of these firms listed on the NGER register; the other 85 firms are control firms chosen using matched-pair design. Content analysis is used to capture the changes in voluntary carbon emission disclosures while logistic regression analysis is used to investigate the determinants that contribute to these disclosures. Ordinary least squares regression results using the number of words and the number of sentences on voluntary carbon emission disclosures are generally consistent with the logistic regression results. This thesis finds voluntary carbon emission disclosures increased over the period 2005 through to 2011. However, heavy emitting firms that later listed on the NGER-registered voluntarily disclosed less carbon emission information during 2005 and 2006 than firms not required to register. Though, by 2008 registered firms’ propensity to voluntary disclose carbon emissions increased at a greater rate than other firms. In addition, it is found sustainability reports convey carbon emission data more than annual reports; however can be raised about the timeliness of information in such reports are not produced annually, if they are produced at all.