The article revisits the climate mitigation targets set by 34 countries at the 2009 Copenhagen Conference of the Parties (COP15) and assesses their implementation. It finds that 12 countries failed to meet their targets, while 7 achieved them through a combination of domestic efforts and carbon leakage through international trade. Key factors in meeting targets were reductions in energy intensity and improvements in the energy mix. However, many countries' efforts fell short of their latest nationally determined contributions (NDCs). The article emphasizes the importance of timely tracking and review of mitigation efforts to meet the Paris Agreement targets. It also highlights the need for policy support to adjust energy and industrial structures to further reduce emission intensity. The analysis reveals that consumption-based emissions, which account for carbon emissions along global supply chains, are crucial for understanding the effectiveness of emission reduction strategies. The study concludes by discussing the challenges and opportunities for achieving NDCs and economic growth, emphasizing the need for continued policy support and collaboration to combat climate change effectively.The article revisits the climate mitigation targets set by 34 countries at the 2009 Copenhagen Conference of the Parties (COP15) and assesses their implementation. It finds that 12 countries failed to meet their targets, while 7 achieved them through a combination of domestic efforts and carbon leakage through international trade. Key factors in meeting targets were reductions in energy intensity and improvements in the energy mix. However, many countries' efforts fell short of their latest nationally determined contributions (NDCs). The article emphasizes the importance of timely tracking and review of mitigation efforts to meet the Paris Agreement targets. It also highlights the need for policy support to adjust energy and industrial structures to further reduce emission intensity. The analysis reveals that consumption-based emissions, which account for carbon emissions along global supply chains, are crucial for understanding the effectiveness of emission reduction strategies. The study concludes by discussing the challenges and opportunities for achieving NDCs and economic growth, emphasizing the need for continued policy support and collaboration to combat climate change effectively.