With the relocation of heavy industries moving from downstream region to upstream and midstream regions in the Yangtze River Economic Belt (YREB), it is critical to encourage coordinated low carbon development in different regions within the YREB. This paper uncovers the evolution of CO₂ emissions in different regions within the YREB for the period of 2000–2017. It decomposes regional CO₂ emission changes using the temporal and cross-regional three-layer logarithmic mean Divisia index (LMDI) method. Besides, it decomposes industrial CO₂ emission changes using the temporal two-layer LMDI method. The research results show that economic growth is the major driver for regional CO₂ emission disparities. The mitigation drivers, such as energy intensity and energy structure, lead to a more decreased CO₂ emission in the downstream region than in the upstream and midstream regions. In addition, it proposes several policy recommendations based upon the local realities, including improving energy efficiency, optimizing energy structure, promoting advanced technologies and equipment transfers, and coordinating the development in the upstream, midstream and downstream regions within the YREB.