This study aims to align major Green Building Rating Systems (GBRSs) with the principles of Whole Life Carbon Assessment (WLCA) to enhance the decarbonisation potential of sustainable buildings. While certification schemes such as BREEAM, LEED, DGNB, and the T & uuml;rkiye-specific YES-TR have contributed significantly to sustainability assessment practices, their weighting structures remain predominantly operational-energy oriented and rarely integrate embodied carbon performance. In this research, a comparative WLCA-based framework was developed to evaluate the carbon relevance of each system by reclassifying their categories into six thematic buckets: energy, materials, water, transport/site, management, and innovation. Each GBRS was then hybrid-weighted using empirical data derived from international whole-life carbon datasets representing typical residential and public building typologies. The results demonstrate that YES-TR and LEED achieve the highest carbon alignment, while BREEAM and DGNB display lower coherence with full life-cycle carbon weighting vectors. Sensitivity analyses confirm that embodied and operational carbon contributions remain the most influential components across all schemes. The findings emphasize the importance of harmonizing GBRS structures with standardized WLCA methods to support policy-level consistency and net-zero building objectives. The proposed framework offers a replicable and data-driven approach for integrating whole-life carbon considerations into green building certification systems at both national and international scales.