As countries commit to achieving zero-carbon targets, just transition has become a core agenda in global climate governance. This analysis reveals that the issue has evolved profoundly from a technical solution with a focus on domestic labor transition to a comprehensive global agenda integrating both technical and political logics. The decision at COP 27 in 2022 to establish a stand-alone work program on just transition pathways marked a critical turning point, expanding its scope to energy, socio-economic dimensions, and other areas, and explicitly anchoring it under the principle of common but differentiated responsibilities. This fundamentally altered the nature and scope of the issue, triggering intense contestation between developed and developing countries. Developed countries prefer limiting the agenda to technical knowledge-sharing to avoid new financial obligations, while developing countries emphasize its nature as an issue of international cooperation, demanding the establishment of a cooperation mechanism with substantive financial and technological support to reflect climate justice. Moving forward, promoting just transition from political contestation to practical cooperation is crucial for fulfilling global climate and sustainable development goals.