The impacts of technological overlap on international collaboration in China’s green innovation endeavors

North-South cooperation in green innovation activities is an essential avenue for promoting global climate governance. This study examines the impact of technological overlap on the scale of international cooperation in environmental technologies (ETs) between Chinese and foreign geographical units. The results show that technological overlap significantly increases the scale of international cooperation in ETs. The main international cooperation partners are located in the G7 countries, with the United States being the most significant partner. Technological overlap has not only promoted China to send many patent inventors to other countries but also encouraged China to introduce more foreign inventors. Further research reveals a significant interaction effect between the scale of existing inventor cooperation, local technological advantages, and technological overlap, which expands the scale of international cooperation. This paper calls for strengthened ET cooperation between developed and developing countries to address climate change.