Objective Urban and rural green space as an important carrier of carbon sink function in territorial space, plays an important role in such aspects as carbon sequestration and oxygen release, cooling and humidification, alleviation of urban heat island effect, and enhancement of social low-carbon publicity. As an important acting point for breaking the urban-rural dual economic and social structure, implementing the scientific development concept, and promoting the coordinated development of regional ecology, urban and rural green space is of great significance for optimizing urban and rural green spatial pattern and improving the efficiency of carbon sink to clarify the research progress of carbon sink.

Methods This research, in the theme of carbon sink in urban and rural green space, conducts a literature metrology analysis on 7, 321 English journals and 2, 807 Chinese academic journal papers. In addition, the research reviews the research progress of carbon sink in urban and rural green space from the four aspects of relevant theories, research objects, research contents and measurement monitoring methods, and summarizes the similarities and differences between and hotspots and duration characteristics of domestic and foreign researches on carbon sink in urban and rural green space.

Results The hotspots and frontiers in both domestic and foreign researches on carbon sink in urban and rural green space mainly focus on the measurement and evaluation of carbon sink, the exploration of carbon sink response mechanism and the optimization practice of green space. Specifically, in terms of the measurement and evaluation of carbon sink, both domestic and foreign researches focus on the accurate measurement of carbon sink in small-scale green spaces such as parks, and the rapid measurement and monitoring of carbon sink in green spaces at or above regional scale. In terms of the response mechanism of carbon sink, both domestic and foreign researches focus on the simulation of carbon cycle process, the evaluation of carbon sink cycle research, and the identification of the driving factors and driving mechanism for carbon sink. In terms of the optimization practice of urban and rural green space, the assessment of carbon footprint in the whole life cycle of green space and the simulation and prediction of carbon sink under different scenarios are research hotspots at present. Domestic and foreign researches follow the same trend in relevant theories, research objects, research contents and measurement and monitoring methods. Specifically, with the expansion of relevant theoretical researches from connotation to extension, the connotations of carbon cycle theory, low-carbon economy theory, carbon footprint theory and other relevant theories have been constantly expanded and gradually penetrated into economic, social and other fields. Research objects have changed from elements to systems, that is, from vegetation, soil and other elements in green spaces to urban and rural green spaces differing in category, scale, ecosystem type and structural level. Research contents and methods tend to be coordinated and improved in multiple fields. On one hand, improving the capacity of carbon sink and coping with climate change are the consistent themes of domestic and foreign researches; on the other hand, the research scope has been expanded from the initial measurement and monitoring of carbon sink to the response mechanism and optimization approach of carbon sink that involve the economic, social and other fields. In the early stage of the research on carbon sink in urban and rural green space, domestic and foreign researches on green space elements have made similar progress, but with the further development of research, they gradually focus on different fields. Due to the large differences between domestic and foreign countries in such aspects as the dimension of territorial space, social ideology and development mode, and organization structure for administrative division management, foreign researches pay more attention to the measurement and evaluation of carbon sink for green space elements and the identification of carbon sink response mechanism for individual green space while in China the research on carbon sink urban and rural green space at the macro scale has entered the stage of rapid development since 2010, with a lot of practical exploration in green space planning and design.

Conclusion This research summarizes existing research results and divides the research process into four stages: the embryonic stage of the research on carbon sink in urban and rural green space (before 2003), the early stage of carbon sink research focusing on ontology elements of urban and rural green space (2003–2010), the development stage of carbon sink research for low-carbon cities and multi-field collaboration (2010–2020), and the new stage of carbon sink research for carbon peaking and carbon neutrality goals (2020 to present). In view of the goal of carbon neutrality, China should establish a monitoring platform and accounting standard system for carbon sink in urban and rural green space to make extensive, consistent and reliable long-term observation of carbon sink in urban and rural green space to serve systematic research on carbon sink in urban and rural green space. Additionally, it is necessary to further clarify the driving response mechanism of carbon sink in urban and rural green space, to optimize the pattern and improve the resource allocation of urban and rural green space. This research explores a multidisciplinary approach to increasing carbon sink with landscape architecture practice as the starting point, with a view to efficiently and comprehensively improving the comprehensive carbon sink efficiency of urban and rural green space.