Since the 18th National Congress of the Communist Party of China, the country has significantly strengthened ecological and environmental protection, making major strides in building a “Beautiful China” and advancing toward a comprehensive green transformation of its economy and society. To support broader participation in the green and low-carbon transition and the co-creation of livable cities, the Institute of Public & Environmental Affairs (IPE), with technical guidance from the Chinese Research Academy of Environmental Sciences and support from the Energy Foundation, developed the City Green Synergy Index and launched a public participation platform. The performance of the 100 surveyed cities has improved steadily compared with the previous round. This positive trend shows that despite many challenges, major Chinese cities have generally maintained sound progress in green and low?carbon development.