Corporate action has always an impact - on the economy, the environment and the society. The Global Reporting Initiative (GRI) has been introduced in order to provide uniform reporting standards for all companies independent from their field and country of operation or their size. Effective environmental reporting is necessary in order to take actions, which are required for decreasing negative impacts on the environment. Thus, reporting standards and methods have to be continuously improved and adopted to our dynamic environment. In this thesis, a conflation of a theoretical approach with a practical approach leads to a conclusion on these probable future improvements and developments of environmental reporting frameworks, especially the GRI. On the theoretic side, critical remarks of academics regarding the GRI are analyzed. ^The practical approach comprises a comparative analysis of environmental reports of four companies in two different sectors, respectively two companies in each sector. This approach allows both, intra-sectorial and cross-sectorial comparison. The compared companies are VERBUND and OMV in the field of energy as well as Wienerberger and Palfinger in the field of construction materials. The juxtaposition of the theoretic and the practical approach results in the conclusion that environmental reporting steers towards a more mandatory framework. Furthermore, environmental reporting moves towards the model of Integrated Reporting, which merges the reports for the economy, the environment and the society. The GRI has to transit from an approach of compatibility with other international reporting frameworks to one of complementarity in order to maintain its prominence. ^The comparative analysis provides evidence that the content of environmental reports are barely comparable and that such comparison between industries is not expedient. Therefore, complete standardization cannot be the goal of future developments of environmental reporting; instead, the goal of transparency becomes more prominent. Moreover, environmental reporting frameworks will increasingly emphasize the importance of a comprehensive materiality principle, which is crucial for the meaningfulness of environmental reports.