Abstract: This thesis aims to examine the nature and extent of climate change disclosure (CCD) of carbon-intensive firms operating in the Gulf Cooperation Council (GCC) region and identify disclosure's main determinants. The study is based on cross-sectional data of 212 firms for the year 2022. Content analysis is preformed to evaluate the scope of sampled firms' CCD in annual and sustainability reports based on a disclosure index that is suitable for the GCC context. The results reveal a concerning low level of carbon disclosure across the region and limited external assurance over disclosed information. In order to identify disclosure influencers, a regression model is developed to test the effect of firm size, age, profitability, leverage, board independence, the existence of sustainability or environmental committees, the adoption of Global Reporting Initiative (GRI) standards, and countries' environmental performance index (EPI) scores on CCD. It is worth noting that the regression results accept the research hypotheses pertaining to the positive relationship between factors including size, debt levels, as well as GRI adoption and CCD at the 1% significance level. Hypotheses concerning the positive impact of both sustainability or environmental committees and EPI scores are also accepted, yet at the 10% significance level only, whereas firm age, profitability, and board independence have not been found to be significant determinants of CCD. The study contributes to the existing body of literature by providing empirical evidence of CCD determinants in the GCC, a region that has been overlooked by prior studies within the same field of research. The insight provided by the study regarding the nature and extent of CCD is expected to improve users' comprehension of the current status of CCD within the region, thus enabling them to approach and evaluate such disclosure critically. Furthermore, research findings can be utilized by regulators to form policies and plans aimed at fostering a culture of greater corporate transparency and sustainability. Keywords: Climate change, Climate change disclosure, Carbon disclosure, GHG, Sustainability reporting