On March 24, 2015, a political bureau meeting of the Communist Party of China Central Committee first proposed the political task of "greening" and placed unprecedented importance on the construction of an ecological civilization, aiming to guide China's economy and society toward green and low carbon development. This study aims to examine the impact of this "greening" policy on China's climate change mitigation. First, from an emissions reduction perspective, this study interprets greening as the process of constantly strengthening society's awareness and willingness regarding emissions reduction. Then, this study incorporates a carbon abatement willingness factor into a nonparametric model, and quantitatively simulates the impact of greening on carbon dioxide (CO2) emissions reduction in China. The results show that China can rapidly decrease its CO2 emissions in the early stages of greening. However, when greening passes a certain stage, it no longer affects CO2 emissions. Thus, the willingness to reduce emissions has a diminishing marginal effect on emissions reduction. Additionally, throughout the greening process, China is expected to reduce its CO2 emissions by 36.08%, or 3718.50 million tons. Finally, the impact of greening on China's CO2 emissions exhibits spatial variation, as its undeveloped western region can achieve greater CO2 emissions reductions by promoting greening. Base on the above results, corresponding policy implications are also provided at the end of this paper.