The escalating pressure and systemic risks generated by climate change, the depletion of global resources, and environmental degradation manifest across numerous sectors through sustainability and green transformation initiatives, thereby necessitating a paradigm shift in the financial sector. As one of the most recent and significant applications of this transformation process, the 'Green Asset Ratio' has been developed to serve as a transparent core performance indicator for banks, particularly in integrating environmental filters into their conventional balance sheets. The legal and technical infrastructure, along with the calculation methodology of the Green Asset Ratio indicator, was initially formulated by the European Banking Authority in alignment with European Union Taxonomy standards, and subsequently integrated into Turkey's national legislation through the regulatory efforts of the Banking Regulation and Supervision Agency. Accordingly, this study examines the emergence, historical development, calculation methodology, and potential implications of the Green Asset Ratio framework. Following the emergence of the Green Asset Ratio spearheaded by the European Union, it is observed that although the legal framework was rapidly enacted in Turkey, banks have not yet commenced regular public disclosures of their corresponding metrics due to the ongoing transition period. One of the primary reasons for this situation can be attributed to the gaps encountered in data verification and documentation processes, particularly regarding corporate borrowers financed by banks. In conclusion, establishing Green Asset Ratio statistics as an accurate, consistent, standardized, and comparable periodic dataset requires not only the integration of the real sector alongside banks, but also strategic policy support from the central government and transparent oversight through rigorous regulatory audits. Fulfilling these prerequisites will play a pivotal role in channeling green capital into Turkey and attaining the broader goals of green transformation and sustainable development.